diff --git a/platform/core.startup/src/org/netbeans/core/startup/ModuleList.java b/platform/core.startup/src/org/netbeans/core/startup/ModuleList.java
index e1595f153ea2..67e22314f568 100644
--- a/platform/core.startup/src/org/netbeans/core/startup/ModuleList.java
+++ b/platform/core.startup/src/org/netbeans/core/startup/ModuleList.java
@@ -24,13 +24,12 @@
 import java.io.BufferedInputStream;
 import java.io.ByteArrayInputStream;
 import java.io.CharArrayWriter;
+import java.io.DataInputStream;
 import java.io.DataOutputStream;
 import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.InputStream;
-import java.io.ObjectInputStream;
-import java.io.ObjectOutputStream;
 import java.io.OutputStream;
 import java.io.OutputStreamWriter;
 import java.io.PushbackInputStream;
@@ -51,6 +50,7 @@
 import java.util.jar.JarFile;
 import java.util.logging.Level;
 import java.util.logging.Logger;
+import java.util.stream.Collectors;
 import org.netbeans.DuplicateException;
 import org.netbeans.Events;
 import org.netbeans.InvalidException;
@@ -111,7 +111,7 @@ final class ModuleList implements Stamps.Updater {
     /** to fire events with */
     private final Events ev;
     /** map from code name (base)s to statuses of modules on disk */
-    private final Map<String,DiskStatus> statuses = new HashMap<String,DiskStatus>(100);
+    private final Map<String, DiskStatus> statuses = new HashMap<>(100);
     /** whether the initial round has been triggered or not */
     private boolean triggered = false;
     /** listener for changes in modules, etc.; see comment on class Listener */
@@ -197,8 +197,7 @@ private File findJarByName(String jar, String name) throws IOException {
                 for (File candidate : jars) {
                     int candidateMajor = -1;
                     SpecificationVersion candidateSpec = null;
-                    JarFile jf = new JarFile(candidate);
-                    try {
+                    try (JarFile jf = new JarFile(candidate)) {
                         java.util.jar.Attributes attr = jf.getManifest().getMainAttributes();
                         String codename = attr.getValue("OpenIDE-Module");
                         if (codename != null) {
@@ -211,8 +210,6 @@ private File findJarByName(String jar, String name) throws IOException {
                         if (sv != null) {
                             candidateSpec = new SpecificationVersion(sv);
                         }
-                    } finally {
-                        jf.close();
                     }
                     if (newest == null || candidateMajor > major || (spec != null && candidateSpec != null && candidateSpec.compareTo(spec) > 0)) {
                         newest = candidate;
@@ -434,7 +431,10 @@ private Object processStatusParam(String k, String v) throws NumberFormatExcepti
     
     /** Just checks that all the right stuff is there.
      */
-    private void sanityCheckStatus(Map<String,Object> m) throws IOException {
+    private static void sanityCheckStatus(Map<String, Object> m) throws IOException {
+        if (m.isEmpty()) {
+            throw new IOException("Must define properties"); // NOI18N
+        }
         String jar = (String) m.get("jar"); // NOI18N
         if (jar == null) {
             throw new IOException("Must define jar param"); // NOI18N
@@ -612,7 +612,7 @@ private String readTo(InputStream is, char delim) throws IOException {
         }
     }
 
-    final Map<String,Map<String,Object>> readCache() {
+    final Map<String, Map<String, Object>> readCache() {
         InputStream is = Stamps.getModulesJARs().asStream("all-modules.dat"); // NOI18N
         if (is == null) {
             // schedule write for later
@@ -620,30 +620,14 @@ final Map<String,Map<String,Object>> readCache() {
             return null;
         }
         LOG.log(Level.FINEST, "Reading cache all-modules.dat");
-        try {
-            ObjectInputStream ois = new ObjectInputStream(is);
-
-            Map<String,Map<String,Object>> ret = new HashMap<String, Map<String, Object>>(1333);
-            while (is.available() > 0) {
-                Map<String, Object> prop = readStatus(ois, false);
-                if (prop == null) {
-                    LOG.log(Level.CONFIG, "Cache is invalid all-modules.dat");
-                    return null;
-                }
-                Set<?> deps;
-                try {
-                    deps = (Set<?>) ois.readObject();
-                } catch (ClassNotFoundException ex) {
-                    throw new IOException(ex);
-                }
-                prop.put("deps", deps);
-                String cnb = (String)prop.get("name"); // NOI18N
-                ret.put(cnb, prop);
+        try (DataInputStream dis = new DataInputStream(is)) {
+            Map<String, Map<String, Object>> cache = new HashMap<>(1333);
+            while (dis.available() > 0) {
+                Map<String, Object> props = readProps(dis);
+                props.put("deps", readDeps(dis));
+                cache.put((String) props.get("name"), props);
             }
-
-
-            is.close();
-            return ret;
+            return cache;
         } catch (IOException ex) {
             LOG.log(Level.INFO, "Cannot read cache", ex);
             writeCache();
@@ -651,6 +635,41 @@ final Map<String,Map<String,Object>> readCache() {
         }
     }
 
+    private static Set<Dependency> readDeps(DataInputStream is) throws IOException {
+        int depCount = is.readInt();
+        if (depCount < 0) {
+            throw new IOException("negative count");
+        } else if (depCount == 0) {
+            return Set.of();
+        }
+        Set<Dependency> deps = new HashSet<>((int) Math.ceil(depCount / 0.75));
+        for (int i = 0; i < depCount; i++) {
+            deps.add(Dependency.read(is));
+        }
+        return deps;
+    }
+
+    private static Map<String, Object> readProps(DataInputStream is) throws IOException {
+        Map<String, Object> props = new HashMap<>(8);
+        for (String str : is.readUTF().split(",")) {
+            String[] entry = str.split("=", 2);
+            // must match computeProperties()
+            try {
+                Object val = switch (entry[0]) {
+                    case "name", "jar" -> entry[1];
+                    case "enabled", "autoload", "eager", "reloadable" -> Boolean.valueOf(entry[1]);
+                    case "startlevel" -> Integer.valueOf(entry[1]);
+                    default -> throw new IOException("unknown key " + entry[0]);
+                };
+                props.put(entry[0], val);
+            } catch (IllegalArgumentException | ArrayIndexOutOfBoundsException ex) {
+                throw new IOException("unexpected value", ex);
+            }
+        }
+        sanityCheckStatus(props);
+        return props;
+    }
+
     final void writeCache() {
         Stamps.getModulesJARs().scheduleSave(this, "all-modules.dat", false);
     }
@@ -661,14 +680,23 @@ public void cacheReady() {
 
     @Override
     public void flushCaches(DataOutputStream os) throws IOException {
-        ObjectOutputStream oss = new ObjectOutputStream(os);
         for (Module m : mgr.getModules()) {
             if (m.isFixed()) {
                 continue;
             }
-            Map<String, Object> prop = computeProperties(m);
-            writeStatus(prop, oss);
-            oss.writeObject(m.getDependencies());
+            // props
+            String list = computeProperties(m).entrySet()
+                    .stream()
+                    .map(e -> e.getKey() + "=" + e.getValue())
+                    .collect(Collectors.joining(","));
+            os.writeUTF(list);
+
+            // deps
+            Set<Dependency> deps = m.getDependencies();
+            os.writeInt(deps.size());
+            for (Dependency dep : deps) {
+                dep.write(os);
+            }
         }
     }
     
@@ -694,7 +722,7 @@ private void writeStatus(Map<String, Object> m, OutputStream os) throws IOExcept
 
         // Use TreeMap to sort the keys by name; since the module status files might
         // be version-controlled we want to avoid gratuitous format changes.
-        for (Map.Entry<String, Object> entry: new TreeMap<String, Object>(m).entrySet()) {
+        for (Map.Entry<String, Object> entry : new TreeMap<>(m).entrySet()) {
             String name = entry.getKey();
             if (
                 name.equals("name") || // NOI18N
@@ -749,11 +777,8 @@ public void run() throws IOException {
                 LOG.fine("ModuleList: (re)writing " + nue.file);
                 FileLock lock = nue.file.lock();
                 try {
-                    OutputStream os = nue.file.getOutputStream(lock);
-                    try {
+                    try (OutputStream os = nue.file.getOutputStream(lock)) {
                         writeStatus(nue.diskProps, os);
-                    } finally {
-                        os.close();
                     }
                 } finally {
                     lock.releaseLock();
@@ -944,12 +969,13 @@ private void moduleChanged(Module m, DiskStatus status) {
         }
     }
     
-    /** Compute what properties we would want to store in XML
+    /** 
+     * Compute what properties we would want to store in XML (or the startup cache)
      * for this module. I.e. 'name', 'reloadable', etc.
      */
-    private Map<String,Object> computeProperties(Module m) {
+    private Map<String, Object> computeProperties(Module m) {
         if (m.isFixed() || ! m.isValid()) throw new IllegalArgumentException("fixed or invalid: " + m); // NOI18N
-        Map<String,Object> p = new HashMap<String,Object>();
+        Map<String, Object> p = new HashMap<>(8);
         p.put("name", m.getCodeNameBase()); // NOI18N
         if (!m.isAutoload() && !m.isEager()) {
             p.put("enabled", m.isEnabled()); // NOI18N
@@ -960,8 +986,7 @@ private Map<String,Object> computeProperties(Module m) {
         if (m.getStartLevel() > 0) {
             p.put("startlevel", m.getStartLevel()); // NOI18N
         }
-        if (m.getHistory() instanceof ModuleHistory) {
-            ModuleHistory hist = (ModuleHistory) m.getHistory();
+        if (m.getHistory() instanceof ModuleHistory hist) {
             p.put("jar", hist.getJar()); // NOI18N
         }
         return p;
@@ -990,6 +1015,7 @@ private final class Listener implements PropertyChangeListener, ErrorHandler, En
         // Property change coming from ModuleManager or some known Module.
         
         private boolean listening = true;
+        @Override
         public void propertyChange(PropertyChangeEvent evt) {
             if (! triggered) throw new IllegalStateException("Property change before trigger()"); // NOI18N
             // REMEMBER this is inside *read* mutex, it is forbidden to even attempt
@@ -1036,15 +1062,19 @@ public void propertyChange(PropertyChangeEvent evt) {
         
         // SAX stuff.
         
+        @Override
         public void warning(SAXParseException e) throws SAXException {
             LOG.log(Level.WARNING, null, e);
         }
+        @Override
         public void error(SAXParseException e) throws SAXException {
             throw e;
         }
+        @Override
         public void fatalError(SAXParseException e) throws SAXException {
             throw e;
         }
+        @Override
         public InputSource resolveEntity(String pubid, String sysid) throws SAXException, IOException {
             if (pubid.equals(PUBLIC_ID)) {
                 if (VALIDATE_XML) {
@@ -1062,6 +1092,7 @@ public InputSource resolveEntity(String pubid, String sysid) throws SAXException
         
         // Changes in Modules/ folder.
         
+        @Override
         public void fileDeleted(FileEvent ev) {
             if (isOurs(ev)) {
                 if (LOG.isLoggable(Level.FINE)) {
@@ -1073,6 +1104,7 @@ public void fileDeleted(FileEvent ev) {
             fileDeleted0(fo.getName(), fo.getExt()/*, ev.getTime()*/);
         }
         
+        @Override
         public void fileDataCreated(FileEvent ev) {
             if (isOurs(ev)) {
                 if (LOG.isLoggable(Level.FINE)) {
@@ -1084,6 +1116,7 @@ public void fileDataCreated(FileEvent ev) {
             fileCreated0(fo.getName(), fo.getExt()/*, ev.getTime()*/);
         }
         
+        @Override
         public void fileRenamed(FileRenameEvent ev) {
             if (isOurs(ev)) {
                 throw new IllegalStateException("I don't rename anything! " + ev); // NOI18N
@@ -1124,6 +1157,7 @@ private void fileDeleted0(String name, String ext/*, long time*/) {
             } // else ignore
         }
         
+        @Override
         public void fileChanged(FileEvent ev) {
             if (isOurs(ev)) {
                 if (LOG.isLoggable(Level.FINE)) {
@@ -1150,9 +1184,11 @@ public void fileChanged(FileEvent ev) {
             } // else ignore
         }
         
+        @Override
         public void fileFolderCreated(FileEvent ev) {
             // ignore
         }
+        @Override
         public void fileAttributeChanged(FileAttributeEvent ev) {
             // ignore
         }
@@ -1549,7 +1585,7 @@ public void run() {
             Map<String, Map<String, Object>> cache = readCache();
             String[] names;
             if (cache != null) {
-                names = cache.keySet().toArray(new String[cache.size()]);
+                names = cache.keySet().toArray(String[]::new);
             } else {
                 FileObject[] children = folder.getChildren();
                 List<String> arr = new ArrayList<String>(children.length);
@@ -1572,7 +1608,7 @@ public void run() {
                         LOG.fine("Strange file encountered in modules folder: " + f);
                     }
                 }
-                names = arr.toArray(new String[0]);
+                names = arr.toArray(String[]::new);
             }
             ev.log(Events.MODULES_FILE_SCANNED, names.length);
             XMLReader reader = null;
@@ -1635,12 +1671,12 @@ public void run() {
                     }
                     ModuleHistory history = new ModuleHistory(jar, "loaded from " + f); // NOI18N
                     Boolean reloadableB = (Boolean) props.get("reloadable"); // NOI18N
-                    boolean reloadable = reloadableB != null ? reloadableB.booleanValue() : false;
-                    boolean enabled = enabledB != null ? enabledB.booleanValue() : false;
+                    boolean reloadable = reloadableB != null ? reloadableB : false;
+                    boolean enabled = enabledB != null ? enabledB : false;
                     Boolean autoloadB = (Boolean) props.get("autoload"); // NOI18N
-                    boolean autoload = autoloadB != null ? autoloadB.booleanValue() : false;
+                    boolean autoload = autoloadB != null ? autoloadB : false;
                     Boolean eagerB = (Boolean) props.get("eager"); // NOI18N
-                    boolean eager = eagerB != null ? eagerB.booleanValue() : false;
+                    boolean eager = eagerB != null ? eagerB : false;
                     NbInstaller.register(name, props.get("deps")); // NOI18N
                     Integer startLevel = (Integer)props.get("startlevel"); // NOI18N
                     Module m = createModule(jarFile, history, reloadable, autoload, eager, startLevel);
diff --git a/platform/core.startup/src/org/netbeans/core/startup/ModuleSystem.java b/platform/core.startup/src/org/netbeans/core/startup/ModuleSystem.java
index 7408107ffa43..90355763b664 100644
--- a/platform/core.startup/src/org/netbeans/core/startup/ModuleSystem.java
+++ b/platform/core.startup/src/org/netbeans/core/startup/ModuleSystem.java
@@ -19,7 +19,6 @@
 
 package org.netbeans.core.startup;
 
-import java.beans.PropertyChangeEvent;
 import java.beans.PropertyChangeListener;
 import java.io.File;
 import java.io.IOException;
@@ -84,11 +83,9 @@ public ModuleSystem(FileSystem systemFileSystem) throws IOException {
 
     final void init(FileSystem systemFileSystem) throws IOException {
         if (Boolean.getBoolean("org.netbeans.core.startup.ModuleSystem.CULPRIT")) Thread.dumpStack(); // NOI18N
-        PropertyChangeListener l = new PropertyChangeListener() {
-            public void propertyChange(PropertyChangeEvent ev) {
-                if (ModuleManager.PROP_CLASS_LOADER.equals(ev.getPropertyName())) {
-                    org.netbeans.core.startup.MainLookup.systemClassLoaderChanged(mgr.getClassLoader());
-                }
+        PropertyChangeListener l = (evt) -> {
+            if (ModuleManager.PROP_CLASS_LOADER.equals(evt.getPropertyName())) {
+                org.netbeans.core.startup.MainLookup.systemClassLoaderChanged(mgr.getClassLoader());
             }
         };
         mgr.addPropertyChangeListener(l);
@@ -135,7 +132,7 @@ public Events getEvents() {
     public List<File> getModuleJars () {
         mgr.mutexPrivileged().enterReadAccess();
         try {
-            List<File> l = new ArrayList<File>();
+            List<File> l = new ArrayList<>();
             for (Module m: mgr.getEnabledModules()) {
                 l.addAll(m.getAllJars());
             }
@@ -158,7 +155,7 @@ public void loadBootModules() {
         // Keep a list of manifest URL bases which we know we do not need to
         // parse. Some of these manifests might be signed, and if so, we do not
         // want to touch them, as it slows down startup quite a bit.
-        Set<File> ignoredJars = new HashSet<File>();
+        Set<File> ignoredJars = new HashSet<>();
         String javaHome = System.getProperty("java.home"); // NOI18N
         if (javaHome != null) {
             File lib = new File(new File(javaHome).getParentFile(), "lib"); // NOI18N
@@ -173,7 +170,7 @@ public void loadBootModules() {
         mgr.mutexPrivileged().enterWriteAccess();
         ev.log(Events.START_LOAD_BOOT_MODULES);
         try {
-            bootModules = new HashSet<Module>(10);
+            bootModules = new HashSet<>(10);
             ClassLoader upperLoader = ModuleSystem.class.getClassLoader();
             // wrap alien loader, so it can be used among parent loaders of module (instanceof ProxyClassLoader)
             ClassLoader loader = new JarClassLoader(Collections.<File>emptyList(), new ClassLoader[] { Module.class.getClassLoader() });
@@ -183,7 +180,7 @@ public void loadBootModules() {
             ev.log(Events.PERF_TICK, "got all manifests"); // NOI18N
             
             // There will be duplicates: cf. #32576.
-            Set<URL> checkedManifests = new HashSet<URL>();
+            Set<URL> checkedManifests = new HashSet<>();
             
             // process libs in 2 passes; first, process bootstrap libraries in platform/libs, creating
             // FixedModules with a classloader that only loads from those libs.
@@ -284,16 +281,16 @@ public void readList() {
         } finally {
             mgr.mutexPrivileged().exitWriteAccess();
         }
-	ev.log(Events.PERF_END, "ModuleSystem.readList"); // NOI18N
+        ev.log(Events.PERF_END, "ModuleSystem.readList"); // NOI18N
     }
     
     /** Install read modules.
      */
     public void restore() {
-	ev.log(Events.PERF_START, "ModuleSystem.restore"); // NOI18N
+        ev.log(Events.PERF_START, "ModuleSystem.restore"); // NOI18N
         mgr.mutexPrivileged().enterWriteAccess();
         try {
-            Set<Module> toTrigger = new HashSet<Module>(bootModules/*Collections.EMPTY_SET*/);
+            Set<Module> toTrigger = new HashSet<>(bootModules/*Collections.EMPTY_SET*/);
             list.trigger(toTrigger);
             mgr.releaseModuleManifests();
         } finally {
@@ -312,9 +309,7 @@ public void restore() {
     public boolean shutDown(final Runnable midHook) {
         try {
             return shutDownAsync(midHook).get();
-        } catch (InterruptedException ex) {
-            Exceptions.printStackTrace(ex);
-        } catch (ExecutionException ex) {
+        } catch (InterruptedException | ExecutionException ex) {
             Exceptions.printStackTrace(ex);
         }
         return false;
@@ -333,12 +328,9 @@ public boolean shutDown(final Runnable midHook) {
      */
     public Future<Boolean> shutDownAsync(final Runnable midHook) {
         mgr.mutexPrivileged().enterWriteAccess();
-        Runnable both = new Runnable() {
-            @Override
-            public void run() {
-                midHook.run();
-                Stamps.getModulesJARs().shutdown();
-            }
+        Runnable both = () -> {
+            midHook.run();
+            Stamps.getModulesJARs().shutdown();
         };
         Future<Boolean> res;
         try {
@@ -370,7 +362,7 @@ final void deployTestModule(File jar) throws IOException {
             // The test module:
             Module tm = null;
             // Anything that needs to be turned back on later:
-            Set<Module> toReenable = new HashSet<Module>();
+            Set<Module> toReenable = new HashSet<>();
             // First see if this refers to an existing module.
             // (If so, make sure it is reloadable.)
             for (Module m : mgr.getModules()) {
@@ -406,7 +398,7 @@ final void deployTestModule(File jar) throws IOException {
                         tm = mgr.create(jar, new ModuleHistory(jar.getAbsolutePath()), true, false, false);
                     } catch (DuplicateException dupe2) {
                         // Should not happen.
-                        throw (IOException) new IOException(dupe2.toString()).initCause(dupe2);
+                        throw new IOException(dupe2);
                     }
                 }
             }
@@ -514,6 +506,7 @@ public static void markForRestart() throws UnsupportedOperationException {
      */
     private static final class QuietEvents extends Events {
         QuietEvents() {}
+        @Override
         protected void logged(String message, Object[] args) {}
     }
 
diff --git a/platform/o.n.bootstrap/src/org/netbeans/Module.java b/platform/o.n.bootstrap/src/org/netbeans/Module.java
index ff81bba3e10a..c040a503f8ce 100644
--- a/platform/o.n.bootstrap/src/org/netbeans/Module.java
+++ b/platform/o.n.bootstrap/src/org/netbeans/Module.java
@@ -20,17 +20,19 @@
 package org.netbeans;
 
 import java.io.DataInput;
+import java.io.DataInputStream;
 import java.io.DataOutput;
 import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
-import java.io.ObjectInput;
-import java.io.ObjectInputStream;
-import java.io.ObjectOutput;
-import java.lang.reflect.Method;
 import java.net.URL;
 import java.security.CodeSource;
-import java.util.*;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.Enumeration;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
 import java.util.jar.Manifest;
 import java.util.logging.Level;
 import java.util.logging.Logger;
@@ -80,7 +82,7 @@ public abstract class Module extends ModuleInfo {
     private ModuleData data;
     private NbInstrumentation instr;
     
-    private static final Object DATA_LOCK = new Object();
+    private final Object DATA_LOCK = new Object();
 
     /** Use ModuleManager.create as a factory. */
     protected Module(ModuleManager mgr, Events ev, Object history, boolean reloadable, boolean autoload, boolean eager) throws IOException {
@@ -115,7 +117,7 @@ protected Module(ModuleManager mgr, Events ev, Object history, ClassLoader class
         enabled = false;
     }
     
-    ModuleData createData(ObjectInput in, Manifest mf) throws IOException {
+    ModuleData createData(DataInput in, Manifest mf) throws IOException {
         if (in != null) {
             return new ModuleData(in);
         } else {
@@ -123,7 +125,7 @@ ModuleData createData(ObjectInput in, Manifest mf) throws IOException {
         }
     }
     
-    final void writeData(ObjectOutput out) throws IOException {
+    final void writeData(DataOutput out) throws IOException {
         data().write(out);
     }
     
@@ -136,6 +138,9 @@ final ModuleData data() {
     }
     
     final ModuleData dataWithCheck() throws InvalidException {
+        if (data != null) {
+            return data;
+        }
         synchronized (DATA_LOCK) {
             if (data != null) {
                 return data;
@@ -143,10 +148,8 @@ final ModuleData dataWithCheck() throws InvalidException {
             Util.err.log(Level.FINE, "Initialize data {0}", getJarFile()); // NOI18N
             InputStream is = mgr.dataFor(getJarFile());
             if (is != null) {
-                try {
-                    ObjectInputStream ois = new ObjectInputStream(is);
+                try (DataInputStream ois = new DataInputStream(is)) {
                     ModuleData mine = createData(ois, null);
-                    ois.close();
                     assert data == null;
                     data = mine;
                     return mine;
@@ -286,8 +289,9 @@ public final boolean provides(String token) {
     
     @Override
     public Set<Dependency> getDependencies() {
-        return new HashSet<Dependency>(Arrays.asList(getDependenciesArray()));
+        return new HashSet<>(Arrays.asList(getDependenciesArray()));
     }
+
     public final Dependency[] getDependenciesArray() {
         Dependency[] dependenciesA;
         try {
@@ -317,8 +321,8 @@ public String getBuildVersion() {
     
     public @Override boolean owns(Class<?> clazz) {
         ClassLoader cl = clazz.getClassLoader();
-        if (cl instanceof Util.ModuleProvider) {
-            return ((Util.ModuleProvider) cl).getModule() == this;
+        if (cl instanceof Util.ModuleProvider mp) {
+            return mp.getModule() == this;
         }
         if (cl != classloader) {
             return false;
@@ -341,11 +345,8 @@ static String findClasspathModuleCodeName(Class<?> clazz) {
                     loc = new URL("jar:" + loc + "!/");
                 }
                 URL manifest = new URL(loc, "META-INF/MANIFEST.MF");
-                InputStream is = manifest.openStream();
-                try {
+                try (InputStream is = manifest.openStream()) {
                     return new Manifest(is).getMainAttributes().getValue("OpenIDE-Module");
-                } finally {
-                    is.close();
                 }
             } catch (IOException x) {
                 Logger.getLogger(Module.class.getName()).log(Level.FINE, null, x);
@@ -500,7 +501,7 @@ public void releaseManifest() {}
     public Set<Object> getProblems() { // cannot use Union2<Dependency,InvalidException> without being binary-incompatible
         if (! isValid()) throw new IllegalStateException("Not valid: " + this); // NOI18N
         if (isEnabled()) return Collections.emptySet();
-        Set<Object> problems = new HashSet<Object>();
+        Set<Object> problems = new HashSet<>();
         for (Union2<Dependency,InvalidException> problem : mgr.missingDependencies(this)) {
             if (problem.hasFirst()) {
                 problems.add(problem.first());
@@ -561,8 +562,8 @@ public Enumeration<URL> findResources(String resources) {
         try { // #149136
             ClassLoader cl = getClassLoader();
 
-            if (cl instanceof ProxyClassLoader) {
-                return ((ProxyClassLoader) cl).findResources(resources);
+            if (cl instanceof ProxyClassLoader pcl) {
+                return pcl.findResources(resources);
             }
             //TODO: other ClassLoaders - what can we expect here? can fallback to getResources for JVM classloaders, and nothing else should be here?
             throw new IllegalStateException("Unexpected ClassLoader: " + cl + ".");
diff --git a/platform/o.n.bootstrap/src/org/netbeans/ModuleData.java b/platform/o.n.bootstrap/src/org/netbeans/ModuleData.java
index 9e9f32710eee..a2eca1ef8f28 100644
--- a/platform/o.n.bootstrap/src/org/netbeans/ModuleData.java
+++ b/platform/o.n.bootstrap/src/org/netbeans/ModuleData.java
@@ -21,8 +21,6 @@
 import java.io.DataInput;
 import java.io.DataOutput;
 import java.io.IOException;
-import java.io.ObjectInput;
-import java.io.ObjectOutput;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
@@ -91,7 +89,7 @@ class ModuleData {
             if (verifyCNBs) {
                 Dependency.create(Dependency.TYPE_MODULE, codeName);
             }
-            codeNameRelease = (cnParse[1] != null) ? ((Integer) cnParse[1]).intValue() : -1;
+            codeNameRelease = (cnParse[1] != null) ? (Integer) cnParse[1] : -1;
             if (cnParse[2] != null) {
                 throw new NumberFormatException(codeName);
             }
@@ -120,7 +118,7 @@ class ModuleData {
                     publicPackages = ZERO_PACKAGE_ARRAY;
                 } else {
                     StringTokenizer tok = new StringTokenizer(exportsS, ", "); // NOI18N
-                    List<Module.PackageExport> exports = new ArrayList<Module.PackageExport>(Math.max(tok.countTokens(), 1));
+                    List<Module.PackageExport> exports = new ArrayList<>(Math.max(tok.countTokens(), 1));
                     while (tok.hasMoreTokens()) {
                         String piece = tok.nextToken();
                         if (piece.endsWith(".*")) { // NOI18N
@@ -148,7 +146,7 @@ class ModuleData {
                     if (exports.isEmpty()) {
                         throw new IllegalArgumentException("Illegal OpenIDE-Module-Public-Packages: " + exportsS); // NOI18N
                     }
-                    publicPackages = exports.toArray(new Module.PackageExport[0]);
+                    publicPackages = exports.toArray(Module.PackageExport[]::new);
                 }
             } else {
                 // XXX new link?
@@ -166,7 +164,7 @@ class ModuleData {
                 String friends = attr.getValue("OpenIDE-Module-Friends"); // NOI18N
                 if (friends != null) {
                     StringTokenizer tok = new StringTokenizer(friends, ", "); // NOI18N
-                    set = new HashSet<String>();
+                    set = new HashSet<>();
                     while (tok.hasMoreTokens()) {
                         String piece = tok.nextToken();
                         if (piece.indexOf('/') != -1) {
@@ -209,7 +207,7 @@ class ModuleData {
         } catch (IllegalArgumentException iae) {
             throw (InvalidException) new InvalidException("While parsing " + codeName + " a dependency attribute: " + iae.toString()).initCause(iae); // NOI18N
         }
-        this.coveredPackages = new HashSet<String>();
+        this.coveredPackages = new HashSet<>();
         this.agentClass = attr.getValue("Agent-Class");
     }
     
@@ -242,41 +240,53 @@ class ModuleData {
         this.publicPackages = null;
         this.provides = computeProvides(m, mf.getMainAttributes(), false, true);
         this.dependencies = computeImported(mf.getMainAttributes());
-        this.coveredPackages = new HashSet<String>();
+        this.coveredPackages = new HashSet<>();
         this.agentClass = getMainAttribute(mf, "Agent-Class"); // NOI18N
         this.fragmentHostCodeName = null;
     }
     
-    ModuleData(ObjectInput dis) throws IOException {
-        try {
-            this.codeName = dis.readUTF();
-            this.codeNameBase = dis.readUTF();
-            this.codeNameRelease = dis.readInt();
-            this.coveredPackages = readStrings(dis, new HashSet<String>(), true);
-            this.dependencies = (Dependency[]) dis.readObject();
-            this.implVersion = dis.readUTF();
-            this.buildVersion = dis.readUTF();
-            this.provides = readStrings(dis);
-            this.friendNames = readStrings(dis, new HashSet<String>(), false);
-            this.specVers = new SpecificationVersion(dis.readUTF());
-            this.publicPackages = Module.PackageExport.read(dis);
-            this.agentClass = dis.readUTF();
-            String s = dis.readUTF();
-            if (s != null) {
-                s = s.trim();
-            }
-            this.fragmentHostCodeName = s == null || s.isEmpty() ? null : s;
-        } catch (ClassNotFoundException cnfe) {
-            throw new IOException(cnfe);
+    ModuleData(DataInput dis) throws IOException {
+        this.codeName = dis.readUTF();
+        this.codeNameBase = dis.readUTF();
+        this.codeNameRelease = dis.readInt();
+        this.coveredPackages = readStrings(dis, new HashSet<>(), true);
+        this.dependencies = readDeps(dis);
+        this.implVersion = dis.readUTF();
+        this.buildVersion = dis.readUTF();
+        this.provides = readStrings(dis);
+        this.friendNames = readStrings(dis, new HashSet<>(), false);
+        this.specVers = new SpecificationVersion(dis.readUTF());
+        this.publicPackages = Module.PackageExport.read(dis);
+        this.agentClass = dis.readUTF();
+        String s = dis.readUTF();
+        if (s != null) {
+            s = s.trim();
+        }
+        this.fragmentHostCodeName = s == null || s.isEmpty() ? null : s;
+    }
+
+    private static Dependency[] readDeps(DataInput dis) throws IOException {
+        int count = Math.max(dis.readInt(), 0);
+        Dependency[] deps = new Dependency[count];
+        for (int i = 0; i < deps.length; i++) {
+            deps[i] = Dependency.read(dis);
         }
+        return deps;
     }
     
-    void write(ObjectOutput dos) throws IOException {
+    void write(DataOutput dos) throws IOException {
         dos.writeUTF(codeName);
         dos.writeUTF(codeNameBase);
         dos.writeInt(codeNameRelease);
         writeStrings(dos, coveredPackages);
-        dos.writeObject(dependencies);
+        if (dependencies == null) {
+            dos.writeInt(0);
+        } else {
+            dos.writeInt(dependencies.length);
+            for (Dependency dep : dependencies) {
+                dep.write(dos);
+            }
+        }
         dos.writeUTF(implVersion);
         dos.writeUTF(buildVersion);
         writeStrings(dos, provides);
@@ -291,7 +301,7 @@ private Dependency[] computeImported(Attributes attr) {
         String pkgs = attr.getValue("Import-Package"); // NOI18N
         List<Dependency> arr = null;
         if (pkgs != null) {
-            arr = new ArrayList<Dependency>();
+            arr = new ArrayList<>();
             StringTokenizer tok = createTokenizer(pkgs); // NOI18N
             while (tok.hasMoreElements()) {
                 String dep = beforeSemicolon(tok);
@@ -301,7 +311,7 @@ private Dependency[] computeImported(Attributes attr) {
         String recomm = attr.getValue("Require-Bundle"); // NOI18N
         if (recomm != null) {
             if (arr == null) {
-                arr = new ArrayList<Dependency>();
+                arr = new ArrayList<>();
             }
             StringTokenizer tok = createTokenizer(recomm); // NOI18N
             while (tok.hasMoreElements()) {
@@ -309,7 +319,7 @@ private Dependency[] computeImported(Attributes attr) {
                 arr.addAll(Dependency.create(Dependency.TYPE_RECOMMENDS, "cnb." + dep)); // NOI18N
             }
         }
-        return arr == null ? null : arr.toArray(new Dependency[0]);
+        return arr == null ? null : arr.toArray(Dependency[]::new);
     }
 
     private static StringTokenizer createTokenizer(String osgiDep) {
@@ -355,7 +365,7 @@ private String[] computeExported(boolean useOSGi, Collection<String> arr, Attrib
     private String[] computeProvides(
         Module forModule, Attributes attr, boolean verifyCNBs, boolean useOSGi
     ) throws InvalidException, IllegalArgumentException {
-        Set<String> arr = new LinkedHashSet<String>();
+        Set<String> arr = new LinkedHashSet<>();
         // Token provides
         String providesS = attr.getValue("OpenIDE-Module-Provides"); // NOI18N
         if (providesS != null) {
@@ -394,11 +404,11 @@ private String[] computeProvides(
     private Dependency[] initDeps(Module forModule, Set<?> knownDeps, Attributes attr)
         throws IllegalStateException, IllegalArgumentException {
         if (knownDeps != null) {
-            return knownDeps.toArray(new Dependency[0]);
+            return knownDeps.toArray(Dependency[]::new);
         }
 
         // deps
-        Set<Dependency> deps = new HashSet<Dependency>(20);
+        Set<Dependency> deps = new HashSet<>(20);
         // First convert IDE/1 -> org.openide/1, so we never have to deal with
         // "IDE deps" internally:
         @SuppressWarnings(value = "deprecation")
@@ -428,7 +438,7 @@ private Dependency[] initDeps(Module forModule, Set<?> knownDeps, Attributes att
         deps.addAll(Dependency.create(Dependency.TYPE_NEEDS, attr.getValue("OpenIDE-Module-Needs"))); // NOI18N
         deps.addAll(Dependency.create(Dependency.TYPE_RECOMMENDS, attr.getValue("OpenIDE-Module-Recommends"))); // NOI18N
         forModule.refineDependencies(deps);
-        return deps.toArray(new Dependency[0]);
+        return deps.toArray(Dependency[]::new);
     }
     
     final String getFragmentHostCodeName() {
@@ -496,13 +506,12 @@ private <T extends Collection<String>> T readStrings(
         }
         return set;
     }
-    private String[] readStrings(ObjectInput dis) throws IOException {
-        List<String> arr = new ArrayList<String>();
+    private String[] readStrings(DataInput dis) throws IOException {
+        List<String> arr = new ArrayList<>();
         readStrings(dis, arr, false);
-        return arr.toArray(new String[0]);
+        return arr.toArray(String[]::new);
     }
-    private void writeStrings(DataOutput dos, Collection<String> set) 
-    throws IOException {
+    private void writeStrings(DataOutput dos, Collection<String> set) throws IOException {
         if (set == null) {
             dos.writeInt(0);
             return;
@@ -512,7 +521,7 @@ private void writeStrings(DataOutput dos, Collection<String> set)
             dos.writeUTF(s);
         }
     }
-    private void writeStrings(ObjectOutput dos, String[] provides) throws IOException {
+    private void writeStrings(DataOutput dos, String[] provides) throws IOException {
         writeStrings(dos, Arrays.asList(provides));
     }
     
diff --git a/platform/o.n.bootstrap/src/org/netbeans/ModuleManager.java b/platform/o.n.bootstrap/src/org/netbeans/ModuleManager.java
index 615b59c6069e..01bf8a1d6d80 100644
--- a/platform/o.n.bootstrap/src/org/netbeans/ModuleManager.java
+++ b/platform/o.n.bootstrap/src/org/netbeans/ModuleManager.java
@@ -29,7 +29,6 @@
 import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
-import java.io.ObjectOutputStream;
 import java.lang.ref.Reference;
 import java.lang.ref.WeakReference;
 import java.net.URL;
@@ -1272,10 +1271,10 @@ public void enable(Set<Module> modules) throws IllegalArgumentException, Invalid
      * from other objects, that can't be compatibly passed 'willEnable' info.
      */
     static class EnableContext {
-        final List<Module> willEnable;
+        final Set<Module> willEnable;
 
         public EnableContext(List<Module> willEnable) {
-            this.willEnable = willEnable;
+            this.willEnable = new HashSet<>(willEnable);
         }
     }
     
@@ -2546,9 +2545,9 @@ public void flushCaches(DataOutputStream os) throws IOException {
                 os.writeUTF(m.getCodeNameBase());
                 
                 ByteArrayOutputStream data = new ByteArrayOutputStream();
-                ObjectOutputStream dos = new ObjectOutputStream(data);
-                m.writeData(dos);
-                dos.close();
+                try (DataOutputStream dos = new DataOutputStream(data)) {
+                    m.writeData(dos);
+                }
                 
                 byte[] arr = data.toByteArray();
                 os.writeInt(arr.length);
diff --git a/platform/o.n.bootstrap/src/org/netbeans/NetigsoModule.java b/platform/o.n.bootstrap/src/org/netbeans/NetigsoModule.java
index 29eb2aea9bcf..63f9466d02a8 100644
--- a/platform/o.n.bootstrap/src/org/netbeans/NetigsoModule.java
+++ b/platform/o.n.bootstrap/src/org/netbeans/NetigsoModule.java
@@ -19,9 +19,9 @@
 
 package org.netbeans;
 
+import java.io.DataInput;
 import java.io.File;
 import java.io.IOException;
-import java.io.ObjectInput;
 import java.net.URL;
 import java.util.Collections;
 import java.util.Enumeration;
@@ -30,7 +30,6 @@
 import java.util.jar.Manifest;
 import java.util.logging.Level;
 import java.util.logging.Logger;
-import org.openide.util.Enumerations;
 import org.openide.util.Exceptions;
 
 /** Special module for representing OSGi bundles 
@@ -51,7 +50,7 @@ public NetigsoModule(Manifest mani, File jar, ModuleManager mgr, Events ev, Obje
     }
 
     @Override
-    ModuleData createData(ObjectInput in, Manifest mf) throws IOException {
+    ModuleData createData(DataInput in, Manifest mf) throws IOException {
         if (in != null) {
             return new ModuleData(in);
         } else {
diff --git a/platform/o.n.bootstrap/src/org/netbeans/Stamps.java b/platform/o.n.bootstrap/src/org/netbeans/Stamps.java
index b5b083a8efbd..fc926d682e76 100644
--- a/platform/o.n.bootstrap/src/org/netbeans/Stamps.java
+++ b/platform/o.n.bootstrap/src/org/netbeans/Stamps.java
@@ -46,7 +46,6 @@
 import java.util.List;
 import java.util.Locale;
 import java.util.Random;
-import java.util.Set;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.concurrent.atomic.AtomicLong;
 import java.util.concurrent.atomic.AtomicReference;
@@ -183,8 +182,7 @@ private ByteBuffer asByteBuffer(String cache, boolean direct, boolean mmap) {
             return null;
         }
         
-        try {
-            FileChannel fc = new FileInputStream(cacheFile).getChannel();
+        try (FileChannel fc = new FileInputStream(cacheFile).getChannel()) {
             ByteBuffer master;
             if (mmap) {
                 master = fc.map(FileChannel.MapMode.READ_ONLY, 0, len[0]);
@@ -198,9 +196,6 @@ private ByteBuffer asByteBuffer(String cache, boolean direct, boolean mmap) {
                 }
                 master.flip();
             }
-
-            fc.close();
-            
             return master;
         } catch (IOException ex) {
             LOG.log(Level.WARNING, "Cannot read cache " + cacheFile, ex); // NOI18N
@@ -309,17 +304,16 @@ private static AtomicLong stamp(boolean checkStampFile) {
     private static void stamp(boolean checkStampFile, AtomicLong result, AtomicReference<File> newestFile) {
         StringBuilder sb = new StringBuilder();
         
-        Set<File> processedDirs = new HashSet<File>();
         String[] relativeDirs = Clusters.relativeDirsWithHome();
         String home = System.getProperty ("netbeans.home"); // NOI18N
         if (home != null) {
-            long stamp = stampForCluster (new File (home), result, newestFile, processedDirs, checkStampFile, true, null);
+            long stamp = stampForCluster (new File (home), result, newestFile, checkStampFile, true, null);
             sb.append(relativeDirs[0]).append('=').append(stamp).append('\n');
         }
         String[] drs = Clusters.dirs();
         for (int i = 0; i < drs.length; i++) {
             final File clusterDir = new File(drs[i]);
-            long stamp = stampForCluster(clusterDir, result, newestFile, processedDirs, checkStampFile, true, null);
+            long stamp = stampForCluster(clusterDir, result, newestFile, checkStampFile, true, null);
             if (stamp != -1) {
                 sb.append("cluster.").append(relativeDirs[i + 1]).append('=').append(stamp).append('\n');
             }
@@ -327,7 +321,7 @@ private static void stamp(boolean checkStampFile, AtomicLong result, AtomicRefer
         File user = Places.getUserDirectory();
         if (user != null) {
             AtomicInteger crc = new AtomicInteger();
-            stampForCluster(user, result, newestFile, new HashSet<File>(), false, false, crc);
+            stampForCluster(user, result, newestFile, false, false, crc);
             sb.append("user=").append(result.longValue()).append('\n');
             sb.append("crc=").append(crc.intValue()).append('\n');
             sb.append("locale=").append(Locale.getDefault()).append('\n');
@@ -352,7 +346,7 @@ observed to contain absolute paths to the NetBeans install directory (netbeans.h
     }
     
     private static long stampForCluster(
-        File cluster, AtomicLong result, AtomicReference<File> newestFile, Set<File> hashSet,
+        File cluster, AtomicLong result, AtomicReference<File> newestFile,
         boolean checkStampFile, boolean createStampFile, AtomicInteger crc
     ) {
         File stamp = new File(cluster, ".lastModified"); // NOI18N
@@ -436,12 +430,10 @@ private static boolean compareAndUpdateFile(File file, String content, AtomicLon
         try {
             byte[] expected = content.getBytes(StandardCharsets.UTF_8);
             byte[] read = new byte[expected.length];
-            FileInputStream is = null;
             boolean areCachesOK;
             boolean writeFile;
             long lastMod;
-            try {
-                is = new FileInputStream(file);
+            try (FileInputStream is = new FileInputStream(file)) {
                 int len = is.read(read);
                 areCachesOK = len == read.length && is.available() == 0 && Arrays.equals(expected, read);
                 writeFile = !areCachesOK;
@@ -451,16 +443,12 @@ private static boolean compareAndUpdateFile(File file, String content, AtomicLon
                 areCachesOK = true;
                 writeFile = true;
                 lastMod = result.get();
-            } finally {
-                if (is != null) {
-                    is.close();
-                }
             }
             if (writeFile) {
                 file.getParentFile().mkdirs();
-                FileOutputStream os = new FileOutputStream(file);
-                os.write(expected);
-                os.close();
+                try (FileOutputStream os = new FileOutputStream(file)) {
+                    os.write(expected);
+                }
                 if (areCachesOK) {
                     file.setLastModified(lastMod);
                 }
@@ -492,7 +480,6 @@ private static void deleteCache(File cacheFile) throws IOException {
                 LOG.log(Level.INFO, "cannot rename (#{0}): {1}", new Object[]{i, cacheFile}); // NOI18N
                 // try harder
                 System.gc();
-                System.runFinalization();
                 LOG.info("after GC"); // NOI18N
                 if (r == null) {
                     r = new Random();
@@ -558,12 +545,8 @@ static void checkPopulateCache() {
         if (is == null) {
             return;
         }
-        ZipInputStream zip = null;
-        FileOutputStream os = null;
-        try {
-            byte[] arr = new byte[4096];
+        try (ZipInputStream zip = new ZipInputStream(is)) {
             LOG.log(Level.FINE, "Found populate.zip about to extract it into {0}", cache);
-            zip = new ZipInputStream(is);
             for (;;) {
                 ZipEntry en = zip.getNextEntry();
                 if (en == null) {
@@ -574,17 +557,10 @@ static void checkPopulateCache() {
                 }
                 File f = new File(cache, en.getName().replace('/', File.separatorChar));
                 f.getParentFile().mkdirs();
-                os = new FileOutputStream(f);
-                for (;;) {
-                    int len = zip.read(arr);
-                    if (len == -1) {
-                        break;
-                    }
-                    os.write(arr, 0, len);
+                try (FileOutputStream os = new FileOutputStream(f)) {
+                    zip.transferTo(os);
                 }
-                os.close();
             }
-            zip.close();
         } catch (IOException ex) {
             LOG.log(Level.INFO, "Failed to populate {0}", cache);
         }
@@ -598,22 +574,12 @@ private static boolean clustersChanged() {
         final String clustersCache = "all-clusters.dat"; // NOI18N
         File f = fileImpl(clustersCache, null, -1); // no timestamp check
         if (f != null) {
-            DataInputStream dis = null;
-            try {
-                dis = new DataInputStream(new FileInputStream(f));
+            try (DataInputStream dis = new DataInputStream(new FileInputStream(f))) {
                 if (Clusters.compareDirs(dis)) {
                     return false;
                 }
             } catch (IOException ex) {
                 return clustersChanged = true;
-            } finally {
-                if (dis != null) {
-                    try {
-                        dis.close();
-                    } catch (IOException ex) {
-                        LOG.log(Level.INFO, null, ex);
-                    }
-                }
             }
         } else {
             // missing cluster file signals caches are OK, for 
@@ -708,12 +674,10 @@ public boolean store(AtomicInteger delay) {
 
                 LOG.log(Level.FINE, "Storing cache {0}", cacheFile);
                 os = new FileOutputStream(cacheFile, append); //append new entries only
-                DataOutputStream dos = new DataOutputStream(new BufferedOutputStream(this, 1024 * 1024));
-                
-                this.delay = delay;
-        
-                updater.flushCaches(dos);
-                dos.close();
+                try (DataOutputStream dos = new DataOutputStream(new BufferedOutputStream(this, 1024 * 1024))) {
+                    this.delay = delay;
+                    updater.flushCaches(dos);
+                }
                 LOG.log(Level.FINE, "Done Storing cache {0}", cacheFile);
             } catch (IOException ex) {
                 LOG.log(Level.WARNING, "Error saving cache {0}", cacheFile);
@@ -953,8 +917,7 @@ static void writeRelativePath(String path, DataOutput dos) throws IOException {
 
     private static void produceRelativePath(String path, Object out) throws IOException {
         if (path.isEmpty()) {
-            if (out instanceof DataOutput) {
-                DataOutput dos = (DataOutput)out;
+            if (out instanceof DataOutput dos) {
                 dos.writeUTF(path);
             }
             return;
@@ -964,7 +927,7 @@ private static void produceRelativePath(String path, Object out) throws IOExcept
         }
         int cnt = 0;
         for (String p : Clusters.dirs()) {
-            if (testWritePath(path, p, "" + cnt, out)) {
+            if (testWritePath(path, p, Integer.toString(cnt), out)) {
                 return;
             }
             cnt++;
@@ -988,8 +951,7 @@ private static boolean testWritePath(String path, String prefix, String codeName
         return false;
     }
     private static void doWritePath(String codeName, String relPath, Object out) throws IOException {
-        if (out instanceof DataOutput) {
-            DataOutput dos = (DataOutput) out;
+        if (out instanceof DataOutput dos) {
             dos.writeUTF(codeName);
             dos.writeUTF(relPath);
         } else {
diff --git a/platform/o.n.bootstrap/src/org/netbeans/StandardModule.java b/platform/o.n.bootstrap/src/org/netbeans/StandardModule.java
index 5d770d8460be..9eb0b47f2f1b 100644
--- a/platform/o.n.bootstrap/src/org/netbeans/StandardModule.java
+++ b/platform/o.n.bootstrap/src/org/netbeans/StandardModule.java
@@ -24,10 +24,10 @@
 // INTERACTIONS SHOULD GO ELSEWHERE.
 // (NbBundle.getLocalizedValue is OK here.)
 
+import java.io.DataInput;
 import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
-import java.io.ObjectInput;
 import java.security.AllPermission;
 import java.security.CodeSource;
 import java.security.PermissionCollection;
@@ -93,7 +93,7 @@ public StandardModule(ModuleManager mgr, Events ev, File jar, Object history, bo
     }
 
     @Override
-    ModuleData createData(ObjectInput in, Manifest mf) throws IOException {
+    ModuleData createData(DataInput in, Manifest mf) throws IOException {
         if (in != null) {
             return new StandardModuleData(in);
         } else {
@@ -132,6 +132,7 @@ ModuleData createData(ObjectInput in, Manifest mf) throws IOException {
      * explicitly suppressed from this list; should only be used for
      * documented localizable attributes such as OpenIDE-Module-Name etc.
      */
+    @Override
     public Object getLocalizedAttribute(String attr) {
         String locb = getManifest().getMainAttributes().getValue("OpenIDE-Module-Localizing-Bundle"); // NOI18N
         boolean usingLoader = false;
@@ -164,11 +165,8 @@ public Object getLocalizedAttribute(String attr) {
                     try {
                         // check if the jar file still exists (see issue 82480)
                         if (jar != null && jar.isFile ()) {
-                            JarFile jarFile = new JarFile(jar, false);
-                            try {
+                            try (JarFile jarFile = new JarFile(jar, false)) {
                                 loadLocalizedProps(jarFile, getManifest());
-                            } finally {
-                                jarFile.close();
                             }
                         } else {
                             Util.err.log(Level.FINE, "Cannot get localized attr {0} from module {1} (missing or deleted JAR file: {2})", new Object[] {attr, getCodeNameBase(), jar});
@@ -203,6 +201,7 @@ public Object getLocalizedAttribute(String attr) {
         }
     }
     
+    @Override
     public boolean isFixed() {
         return false;
     }
@@ -252,13 +251,10 @@ private void loadManifest() throws IOException {
                 jarBeingOpened = physicalJar; // might be null
                 ensurePhysicalJar();
                 jarBeingOpened = physicalJar; // might have changed
-                JarFile jarFile = new JarFile(physicalJar, false);
-                try {
+                try (JarFile jarFile = new JarFile(physicalJar, false)) {
                     Manifest m = jarFile.getManifest();
                     if (m == null) throw new IOException("No manifest found in " + physicalJar); // NOI18N
                     manifest = m;
-                } finally {
-                    jarFile.close();
                 }
             } else {
                 jarBeingOpened = jar;
@@ -346,11 +342,8 @@ private void loadLocalizedProps(JarFile jarFile, Manifest m) throws IOException
                 // May not be present in base JAR: might only be in e.g. default locale variant.
                 if (bundleFile != null) {
                     localizedProps = new Properties();
-                    InputStream is = jarFile.getInputStream(bundleFile);
-                    try {
+                    try (InputStream is = jarFile.getInputStream(bundleFile)) {
                         localizedProps.load(is);
-                    } finally {
-                        is.close();
                     }
                 }
             }
@@ -373,23 +366,17 @@ private void loadLocalizedProps(JarFile jarFile, Manifest m) throws IOException
                     File localeJar = pair.file;
                     String suffix = pair.suffix;
                     String rsrc = name + suffix + ext;
-                    JarFile localeJarFile = new JarFile(localeJar, false);
-                    try {
+                    try (JarFile localeJarFile = new JarFile(localeJar, false)) {
                         ZipEntry bundleFile = localeJarFile.getEntry(rsrc);
                         // Need not exist in all locale variants.
                         if (bundleFile != null) {
                             if (localizedProps == null) {
                                 localizedProps = new Properties();
                             } // else append and overwrite base-locale values
-                            InputStream is = localeJarFile.getInputStream(bundleFile);
-                            try {
+                            try (InputStream is = localeJarFile.getInputStream(bundleFile)) {
                                 localizedProps.load(is);
-                            } finally {
-                                is.close();
                             }
                         }
-                    } finally {
-                        localeJarFile.close();
                     }
                 }
             }
@@ -437,6 +424,7 @@ public List<File> getAllJars() {
      * Must be called from within a write mutex.
      * @param r whether the module should be considered reloadable
      */
+    @Override
     public void setReloadable(boolean r) {
         getManager().assertWritable();
         if (reloadable != r) {
@@ -449,6 +437,7 @@ public void setReloadable(boolean r) {
      * If an exception is thrown, the module is considered
      * to be in an invalid state.
      */
+    @Override
     public void reload() throws IOException {
         // Probably unnecessary but just in case:
         destroyPhysicalJar();
@@ -468,6 +457,7 @@ public void reload() throws IOException {
     /** Turn on the classloader. Passed a list of parent modules to use.
      * The parents should already have had their classloaders initialized.
      */
+    @Override
     protected void classLoaderUp(Set<Module> parents) throws IOException {
         if (Util.err.isLoggable(Level.FINE)) {
             Util.err.fine("classLoaderUp on " + this + " with parents " + parents);
@@ -533,7 +523,7 @@ protected void classLoaderUp(Set<Module> parents) throws IOException {
                 classloader = createNewClassLoader(classp, loaders);
             } catch (IllegalArgumentException iae) {
                 // Should not happen, but just in case.
-                throw (IOException) new IOException(iae.toString()).initCause(iae);
+                throw new IOException(iae);
             }
         }
     }
@@ -551,13 +541,15 @@ protected ClassLoader getParentLoader(Module parent) {
     }
 
     /** Turn off the classloader and release all resources. */
+    @Override
     protected void classLoaderDown() {
-        if (classloader instanceof ProxyClassLoader) {
-            ((ProxyClassLoader)classloader).destroy();
+        if (classloader instanceof ProxyClassLoader pcl) {
+            pcl.destroy();
         }
         classloader = null;
     }
     /** Should be called after turning off the classloader of one or more modules &amp; GC'ing. */
+    @Override
     protected void cleanup() {
         if (isEnabled()) throw new IllegalStateException("cleanup on enabled module: " + this); // NOI18N
         if (classloader != null) throw new IllegalStateException("cleanup on module with classloader: " + this); // NOI18N
@@ -566,6 +558,7 @@ protected void cleanup() {
     }
     
     /** Notify the module that it is being deleted. */
+    @Override
     public void destroy() {
         moduleJARs.remove(jar);
     }
@@ -609,6 +602,7 @@ public OneModuleClassLoader(List<File> classp, ClassLoader[] parents) throws Ill
             super(classp, parents, false, StandardModule.this);
         }
         
+        @Override
         public Module getModule() {
             return StandardModule.this;
         }
@@ -681,8 +675,8 @@ public Module getModule() {
                 return false;
             }
             Module other;
-            if (parent instanceof Util.ModuleProvider) {
-                other = ((Util.ModuleProvider)parent).getModule();
+            if (parent instanceof Util.ModuleProvider mp) {
+                other = mp.getModule();
             } else {
                 other = null;
             }
diff --git a/platform/o.n.bootstrap/src/org/netbeans/StandardModuleData.java b/platform/o.n.bootstrap/src/org/netbeans/StandardModuleData.java
index 8ec3d96791cc..9daa11d2ba50 100644
--- a/platform/o.n.bootstrap/src/org/netbeans/StandardModuleData.java
+++ b/platform/o.n.bootstrap/src/org/netbeans/StandardModuleData.java
@@ -22,10 +22,8 @@
 import java.io.DataOutput;
 import java.io.File;
 import java.io.IOException;
-import java.io.ObjectInput;
-import java.io.ObjectOutput;
-import java.io.UnsupportedEncodingException;
 import java.net.URLDecoder;
+import java.nio.charset.StandardCharsets;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
@@ -47,7 +45,7 @@ final class StandardModuleData extends ModuleData {
      * different modules try to load the same extension (which would cause them
      * to both load their own private copy, which may not be intended).
      */
-    private static final Map<File, Set<File>> extensionOwners = new HashMap<File, Set<File>>();
+    private static final Map<File, Set<File>> extensionOwners = new HashMap<>();
     /** Set of locale-variants JARs for this module (or null).
      * Added explicitly to classloader, and can be used by execution engine.
      */
@@ -80,12 +78,7 @@ public StandardModuleData(Manifest mf, StandardModule forModule) throws InvalidE
         if (classPath != null) {
             StringTokenizer tok = new StringTokenizer(classPath);
             while (tok.hasMoreTokens()) {
-                String ext;
-                try {
-                    ext = URLDecoder.decode(tok.nextToken(), "UTF-8");
-                } catch (UnsupportedEncodingException ex) {
-                    throw new IllegalStateException(ex);
-                }
+                String ext = URLDecoder.decode(tok.nextToken(), StandardCharsets.UTF_8);
                 File extfile;
                 if (ext.equals("${java.home}/lib/ext/jfxrt.jar")) { // NOI18N
                     // special handling on JDK7
@@ -158,7 +151,7 @@ public StandardModuleData(Manifest mf, StandardModule forModule) throws InvalidE
         }
     }
 
-    public StandardModuleData(ObjectInput dis) throws IOException {
+    public StandardModuleData(DataInput dis) throws IOException {
         super(dis);
         localeVariants = readFiles(dis);
         localeExtensions = readFiles(dis);
@@ -166,7 +159,7 @@ public StandardModuleData(ObjectInput dis) throws IOException {
     }
 
     @Override
-    void write(ObjectOutput dos) throws IOException {
+    void write(DataOutput dos) throws IOException {
         super.write(dos);
         writeFiles(dos, localeVariants);
         writeFiles(dos, localeExtensions);
@@ -175,7 +168,7 @@ void write(ObjectOutput dos) throws IOException {
     
     private static Set<File> readFiles(DataInput is) throws IOException {
         int size = is.readInt();
-        Set<File> set = new HashSet<File>();
+        Set<File> set = new HashSet<>((int) Math.ceil(size / 0.75));
         while (size-- > 0) {
             set.add(new File(Stamps.readRelativePath(is)));
         }
diff --git a/platform/openide.modules/src/org/openide/modules/Dependency.java b/platform/openide.modules/src/org/openide/modules/Dependency.java
index f30b589bea03..e4c59a7b6d80 100644
--- a/platform/openide.modules/src/org/openide/modules/Dependency.java
+++ b/platform/openide.modules/src/org/openide/modules/Dependency.java
@@ -19,15 +19,18 @@
 
 package org.openide.modules;
 
+import java.io.DataInput;
+import java.io.DataOutput;
+import java.io.IOException;
 import java.io.Serializable;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Map;
+import java.util.Objects;
 import java.util.Set;
 import java.util.StringTokenizer;
 import java.util.regex.Pattern;
-import org.openide.util.BaseUtilities;
 
 /** A dependency a module can have. Since version 7.10 this class is
  * {@link Serializable}.
@@ -115,6 +118,7 @@ public final class Dependency implements Serializable {
 
     /** Implementation version of the Java VM. */
     public static final String VM_IMPL = System.getProperty("java.vm.version"); // NOI18N
+
     private final int type;
     private final int comparison;
     private final String name;
@@ -361,6 +365,39 @@ public static Set<Dependency> create(int type, String body) throws IllegalArgume
         return deps;
     }
 
+    /**
+     * Reads a dependency from the stream.
+     *
+     * Custom persistence for faster serialization.
+     * @see #write(java.io.DataOutput) 
+     */
+    public static Dependency read(DataInput is) throws IOException {
+        int type = is.readByte();
+        int comp = is.readByte();
+        String name = is.readUTF();
+        if (name == null || name.isBlank()) {
+            throw new IOException("name expected");
+        }
+        String version = is.readUTF();
+        if (version.isBlank()) {
+            version = null;
+        }
+        return new Dependency(type, name, comp, version);
+    }
+
+    /**
+     * Writes a dependency to the stream.
+     *
+     * Custom persistence for faster serialization.
+     * @see #read(java.io.DataInput)
+     */
+    public void write(DataOutput os) throws IOException {
+        os.writeByte(getType());
+        os.writeByte(getComparison());
+        os.writeUTF(getName());
+        os.writeUTF(getVersion() != null ? getVersion() : "");
+    }
+
     /** Get the type. */
     public final int getType() {
         return type;
@@ -390,8 +427,7 @@ public boolean equals(Object o) {
 
         Dependency d = (Dependency) o;
 
-        return (type == d.type) && (comparison == d.comparison) && name.equals(d.name) &&
-        BaseUtilities.compareObjects(version, d.version);
+        return (type == d.type) && (comparison == d.comparison) && name.equals(d.name) && Objects.equals(version, d.version);
     }
 
     /** Overridden to hash by contents. */
@@ -522,15 +558,18 @@ public DependencyKey(Dependency d) {
             //System.err.println("Key for " + d + " is " + this);
         }
 
+        @Override
         public int hashCode() {
             return name.hashCode();
         }
 
+        @Override
         public boolean equals(Object o) {
             return (o instanceof DependencyKey) && ((DependencyKey) o).name.equals(name) &&
             (((DependencyKey) o).type == type);
         }
 
+        @Override
         public String toString() {
             return "DependencyKey[" + name + "," + type + "]"; // NOI18N
         }