Add Java API for non-streaming ASR (#807)

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

@@ -0,0 +1,55 @@
+// Copyright 2024 Xiaomi Corporation
+package com.k2fsa.sherpa.onnx;
+
+public class OfflineRecognizer {
+    static {
+        System.loadLibrary("sherpa-onnx-jni");
+    }
+
+    private long ptr = 0; // this is the asr engine ptrss
+
+    public OfflineRecognizer(OfflineRecognizerConfig config) {
+        ptr = newFromFile(config);
+    }
+
+    public void decode(OfflineStream s) {
+        decode(ptr, s.getPtr());
+    }
+
+    public OfflineStream createStream() {
+        long p = createStream(ptr);
+        return new OfflineStream(p);
+    }
+
+    @Override
+    protected void finalize() throws Throwable {
+        release();
+    }
+
+    // You'd better call it manually if it is not used anymore
+    public void release() {
+        if (this.ptr == 0) {
+            return;
+        }
+        delete(this.ptr);
+        this.ptr = 0;
+    }
+
+    public OfflineRecognizerResult getResult(OfflineStream s) {
+        Object[] arr = getResult(s.getPtr());
+        String text = (String) arr[0];
+        String[] tokens = (String[]) arr[1];
+        float[] timestamps = (float[]) arr[2];
+        return new OfflineRecognizerResult(text, tokens, timestamps);
+    }
+
+    private native void delete(long ptr);
+
+    private native long newFromFile(OfflineRecognizerConfig config);
+
+    private native long createStream(long ptr);
+
+    private native void decode(long ptr, long streamPtr);
+
+    private native Object[] getResult(long streamPtr);
+}