Add Java API for text-to-speech (#811)

sherpa-onnx/java-api/src/com/k2fsa/sherpa/onnx/GeneratedAudio.java

@@ -0,0 +1,32 @@
+// Copyright 2024 Xiaomi Corporation
+
+package com.k2fsa.sherpa.onnx;
+
+public class GeneratedAudio {
+    static {
+        System.loadLibrary("sherpa-onnx-jni");
+    }
+
+    private final float[] samples;
+    private final int sampleRate;
+
+    public GeneratedAudio(float[] samples, int sampleRate) {
+        this.samples = samples;
+        this.sampleRate = sampleRate;
+    }
+
+    public int getSampleRate() {
+        return sampleRate;
+    }
+
+    public float[] getSamples() {
+        return samples;
+    }
+
+    // return true if saved successfully.
+    public boolean save(String filename) {
+        return saveImpl(filename, samples, sampleRate);
+    }
+
+    private native boolean saveImpl(String filename, float[] samples, int sampleRate);
+}