0.Introduction
--------------

Java wrapper `com.k2fsa.sherpa.onnx.OnlineRecognizer` for `sherpa-onnx`. Java is a cross-platform language; you can build jni .so lib according to your system, and then use the same java api for all your platform.

```xml
Depend on:
  Openjdk 1.8
```

---

1.Compile libsherpa-onnx-jni.so
-------------------------------

Compile sherpa-onnx/jni/jni.cc according to your system.
Example for Ubuntu 18.04 LTS, Openjdk 1.8.0_362:

```xml
  git clone https://github.com/k2-fsa/sherpa-onnx
  cd sherpa-onnx
  mkdir build
  cd build
  cmake -DCMAKE_BUILD_TYPE=Release -DBUILD_SHARED_LIBS=ON -DSHERPA_ONNX_ENABLE_JNI=ON ..
  make -j6
```

---

2.Download asr model files
--------------------------

[click here for more detail](https://k2-fsa.github.io/sherpa/onnx/pretrained_models/index.html)
--------------------------

3.Config model config.cfg
-------------------------

```xml
  #model config  
  sample_rate=16000                  
  feature_dim=80
  rule1_min_trailing_silence=2.4
  rule2_min_trailing_silence=1.2
  rule3_min_utterance_length=20
  encoder=/sherpa-onnx/build/bin/sherpa-onnx-streaming-zipformer-bilingual-zh-en-2023-02-20/encoder-epoch-99-avg-1.onnx
  decoder=/sherpa-onnx/build/bin/sherpa-onnx-streaming-zipformer-bilingual-zh-en-2023-02-20/decoder-epoch-99-avg-1.onnx
  joiner=/sherpa-onnx/build/bin/sherpa-onnx-streaming-zipformer-bilingual-zh-en-2023-02-20/joiner-epoch-99-avg-1.onnx
  tokens=/sherpa-onnx/build/bin/sherpa-onnx-streaming-zipformer-bilingual-zh-en-2023-02-20/tokens.txt
  num_threads=4
  enable_endpoint_detection=false
  decoding_method=greedy_search
  max_active_paths=4
```

---

4.A simple java example
-----------------------

refer to [java_api_example](https://github.com/k2-fsa/sherpa-onnx/blob/master/java-api-examples/src/DecodeFile.java) for more detail.

```java
    import com.k2fsa.sherpa.onnx.OnlineRecognizer;
    import com.k2fsa.sherpa.onnx.OnlineStream;
    String cfgpath=appdir+"/modelconfig.cfg";
    OnlineRecognizer.setSoPath(soPath);   //set so lib path

    OnlineRecognizer rcgOjb = new OnlineRecognizer();   //create a recognizer
    rcgOjb = new OnlineRecognizer(cfgFile);    //set model config file 
    CreateStream streamObj=rcgOjb.CreateStream();       //create a stream for read wav data
    float[] buffer = rcgOjb.readWavFile(wavfilename); // read data from file
    streamObj.acceptWaveform(buffer); // feed stream with data
    streamObj.inputFinished(); // tell engine you done with all data
    OnlineStream ssObj[] = new OnlineStream[1];
    while (rcgOjb.isReady(streamObj)) { // engine is ready for unprocessed data
                ssObj[0] = streamObj;
                rcgOjb.decodeStreams(ssObj); // decode for multiple stream
                // rcgOjb.DecodeStream(streamObj);   // decode for single stream
            }

    String recText = "simple:" + rcgOjb.getResult(streamObj) + "\n";
    byte[] utf8Data = recText.getBytes(StandardCharsets.UTF_8);
    System.out.println(new String(utf8Data));
    rcgOjb.reSet(streamObj);
    rcgOjb.releaseStream(streamObj); // release stream
    rcgOjb.release(); // release recognizer
```

---

5.Makefile
----------

OS Ubuntu 18.04 LTS
Build package path: /sherpa-onnx/java-api-examples/lib/sherpaonnx.jar

5.1 Build

```bash
    cd sherpa-onnx/java-api-examples
    make all
```

5.2 Run DecodeFile example

```bash
    make runfile
```

5.3 Run DecodeMic example

```bash
    make runmic
```