Fix issue #19 - allow to load models from InputStream/URL/URI

src/main/java/com/github/jfasttext/JFastText.java

@@ -3,15 +3,40 @@
 import org.bytedeco.javacpp.PointerPointer;
 
 import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.net.MalformedURLException;
+import java.net.URI;
+import java.net.URL;
+import java.nio.file.CopyOption;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.StandardCopyOption;
 import java.util.ArrayList;
 import java.util.List;
 
 public class JFastText {
 
-    private FastTextWrapper.FastTextApi fta;
+    private FastTextWrapper.FastTextApi fta = new FastTextWrapper.FastTextApi();;
 
     public JFastText() {
-        fta = new FastTextWrapper.FastTextApi();
+    }
+
+    public JFastText(final String modelFile) {
+        loadModel(modelFile);
+    }
+
+    public JFastText(final URI modelUri) throws IOException {
+        loadModel(modelUri);
+    }
+
+    public JFastText(final URL modelUrl) throws IOException {
+        loadModel(modelUrl);
+    }
+
+    public JFastText(final InputStream modelStream) throws IOException {
+        loadModel(modelStream);
     }
 
     public void runCmd(String[] args) {
@@ -22,9 +47,9 @@ public void runCmd(String[] args) {
         fta.runCmd(cArgs.length, new PointerPointer(cArgs));
     }
 
-    public void loadModel(String modelFile) {
+    public void loadModel(String modelFile) throws IllegalArgumentException {
         if (!new File(modelFile).exists()) {
-            throw new IllegalArgumentException("Model file doesn't exist!");
+            throw new IllegalArgumentException("Model file " + modelFile + " doesn't exist!");
         }
         if (!fta.checkModel(modelFile)) {
             throw new IllegalArgumentException(
@@ -33,6 +58,39 @@ public void loadModel(String modelFile) {
         fta.loadModel(modelFile);
     }
 
+    /**
+     * Loads model from location specified by URI, by copying its content into local file & then loading it.
+     *
+     * @param modelUri location of the model
+     */
+    public void loadModel(URI modelUri) throws IOException {
+        loadModel(modelUri.toURL());
+    }
+
+    /**
+     * Loads model from location specified by URL, by copying its content into local file & then loading it.
+     *
+     * @param modelUrl location of the model
+     */
+    public void loadModel(URL modelUrl) throws IOException {
+        loadModel(modelUrl.openStream());
+    }
+
+    /**
+     * Loads model given InputStream, by copying its content into local file & then loading it.
+     *
+     * @param modelStream stream for model
+     */
+    public void loadModel(InputStream modelStream) throws IOException {
+        Path tmpFile = Files.createTempFile("jft-", ".model");
+        try {
+            Files.copy(modelStream, tmpFile, StandardCopyOption.REPLACE_EXISTING);
+            loadModel(tmpFile.toString());
+        } finally {
+            Files.deleteIfExists(tmpFile);
+        }
+    }
+
     public void unloadModel() {
         fta.unloadModel();
     }

src/test/java/com/github/jfasttext/JFastTextTest.java

@@ -4,6 +4,9 @@
 import org.junit.Test;
 import org.junit.runners.MethodSorters;
 
+import java.io.FileInputStream;
+import java.io.InputStream;
+import java.net.URL;
 import java.util.List;
 
 @FixMethodOrder(MethodSorters.NAME_ASCENDING)
@@ -57,8 +60,7 @@ public void test04Predict() throws Exception {
 
     @Test
     public void test05PredictProba() throws Exception {
-        JFastText jft = new JFastText();
-        jft.loadModel("src/test/resources/models/supervised.model.bin");
+        JFastText jft = new JFastText("src/test/resources/models/supervised.model.bin");
         String text = "What is the most popular sport in the US ?";
         JFastText.ProbLabel predictedProbLabel = jft.predictProba(text);
         System.out.printf("\nText: '%s', label: '%s', probability: %f\n",
@@ -67,8 +69,7 @@ public void test05PredictProba() throws Exception {
 
     @Test
     public void test06MultiPredictProba() throws Exception {
-        JFastText jft = new JFastText();
-        jft.loadModel("src/test/resources/models/supervised.model.bin");
+        JFastText jft = new JFastText("src/test/resources/models/supervised.model.bin");
         String text = "Do you like soccer ?";
         System.out.printf("Text: '%s'\n", text);
         for (JFastText.ProbLabel predictedProbLabel: jft.predictProba(text, 2)) {
@@ -79,11 +80,12 @@ public void test06MultiPredictProba() throws Exception {
 
     @Test
     public void test07GetVector() throws Exception {
-        JFastText jft = new JFastText();
-        jft.loadModel("src/test/resources/models/supervised.model.bin");
-        String word = "soccer";
-        List<Float> vec = jft.getVector(word);
-        System.out.printf("\nWord embedding vector of '%s': %s\n", word, vec);
+        try (InputStream is = new FileInputStream("src/test/resources/models/supervised.model.bin")) {
+            JFastText jft = new JFastText(is);
+            String word = "soccer";
+            List<Float> vec = jft.getVector(word);
+            System.out.printf("\nWord embedding vector of '%s': %s\n", word, vec);
+        }
     }
 
     /**
@@ -92,8 +94,7 @@ public void test07GetVector() throws Exception {
     @Test
     public void test08ModelInfo() throws Exception {
         System.out.printf("\nSupervised model information:\n");
-        JFastText jft = new JFastText();
-        jft.loadModel("src/test/resources/models/supervised.model.bin");
+        JFastText jft = new JFastText("src/test/resources/models/supervised.model.bin");
         System.out.printf("\tnumber of words = %d\n", jft.getNWords());
         System.out.printf("\twords = %s\n", jft.getWords());
         System.out.printf("\tlearning rate = %g\n", jft.getLr());
@@ -120,4 +121,15 @@ public void test09ModelUnloading() throws Exception {
         System.out.println("Unloading model ...");
         jft.unloadModel();
     }
+
+    /**
+     * Loads model from specified URL (resource, web, etc.)
+     *
+     */
+    @Test
+    public void test10ModelFromURL() throws Exception {
+        URL modelUrl = this.getClass().getClassLoader().getResource("models/supervised.model.bin");
+        JFastText jft = new JFastText(modelUrl);
+        System.out.printf("\tnumber of words = %d\n", jft.getNWords());
+    }
 }