Okhttp、Retrofit进度获取(一行代码搞定)

起因

对于广大Android开发者来说，最近用的最多的网络库，莫过于Okhttp啦（Retrofit依赖Okhttp）。
Okhttp不像SDK内置的HttpUrlConnection一样，可以明确的获取数据读写的过程，我们需要执行一些操作。

介绍

Retrofit依赖Okhttp、Okhttp依赖于Okio。那么Okio又是什么鬼？别急，看官方介绍：
Okio is a library that complements java.io and java.nio to make it much easier to access, store, and process your data.
翻译过来就是，Okio是一个实现了java.io和java.nio的一个类库，它让连接，存储，处理你的数据更加轻松~（Okio既是读写相关类库，获取进度要从Okio入手）。
好吧，对于广大开发者来说，内心是这样的：TM又要看你文档和用例，按你规则走，轻松个毛啊！
其实，读下API，看下Example熟悉后，人家设计的还是很棒哒。
废话不多说，先看效果。

效果

tnetprogress-6.gif

实际代码：

 //添加下载拦截器(this参数是实现下载进度接口的对象) 
 mDownClient = new OkHttpClient.Builder()
              //只需要一行代码就行了
            .addNetworkInterceptor(new DownloadInterceptor(this))
            .build();
            
 //添加上传拦截器(this参数是实现上传回调接口的对象)            
 mUploadClient = new OkHttpClient.Builder()
              //只需要一行代码就行了
            .addNetworkInterceptor(new UploadInterceptor(this))
            .build();

你只需要一行代码是不行的！我为什么行？因为这是我写的封装类库啊~（最后放地址）

思路

Okhttp依赖Okio进行了数据的读写动作，我们需要找到Okio进行处理。那么，如何加上呢？
Okhttp可以添加Interceptor（拦截器），我们可以通过拦截器的接口方法，获取对应的responseBody、requestBody对象进行操作。然后我们就获取了读写相关的实现方法。具体实现是通过Source、Sink对象。

Source官方解释：Supplies a stream of bytes. Use this interface to read data from wherever it's located。

Sink官方解释：Receives a stream of bytes. Use this interface to write data wherever it's needed。

一句话概括：Source对象是对输入流的包装（下载读数据），Sink是对输出流的包装（写数据上传）。

实现

根据需要添加下载、上传Interceptor

     //添加下载拦截器(this参数是实现下载进度接口的对象) 
    mDownClient = new OkHttpClient.Builder()
            .addNetworkInterceptor(new DownloadInterceptor(this))
            .build();
            
 //添加上传拦截器(this参数是实现上传回调接口的对象)            
 mUploadClient = new OkHttpClient.Builder()
            .addNetworkInterceptor(new UploadInterceptor(this))
            .build(); 

拦截器具体实现

 //下载拦截器     
public class DownloadInterceptor implements Interceptor {
private OnDownloadListener mListener;

public DownloadInterceptor( OnDownloadListener listener) {
    mListener = listener;
}

@Override
public Response intercept(Chain chain) throws IOException {
    //封装ressponse对象
    Response response = wrapResponse(chain.proceed(chain.request()));
    return response;
}

private Response wrapResponse(Response response) {
    if (response == null || response.body() == null) {
        return response;
    }
    //获取处理后的response对象
    Response wrapResponse = getWrapResponse(response);
    return wrapResponse;
}

private Response getWrapResponse(Response response) {
    ProgressInfo info = new ProgressInfo();
    info.setTime(System.currentTimeMillis()+"");
    info.setUrl(response.request().url().toString());
    Response.Builder builder = response.newBuilder();
    //封装responseBody，传入相关参数，获取进度数据回调
    return builder.body(new WrapResponseBody(response.body(),info,mListener)).build();
}
}
   --------------------------------------分割---------------------------------------
 //上传拦截器
 public class UploadInterceptor implements Interceptor {
private OnUploadListener mListener;

public UploadInterceptor(OnUploadListener listener) {
    mListener = listener;
}

@Override
public Response intercept(Chain chain) throws IOException {
    //封装request对象
    Request request = wrapRequest(chain.request());
    Response response = chain.proceed(request);
    return response;
}


private Request wrapRequest(Request request) {
    if (request == null || request.body() == null) {
        return request;
    }
    Request.Builder builder = request.newBuilder();
    ProgressInfo info = new ProgressInfo();
    HttpUrl url = request.url();
    info.setUrl(url.toString());
    info.setTime(System.currentTimeMillis()+"");
    //封装requestBody，传入参数，获取数据进度回调
    builder.method(request.method(),new WrapRequestBody(request.body(),info,mListener));
    return builder.build();
   }
  }

responseBody、requestBody相关实现

//继承ResponseBody实现具体方法
public class WrapResponseBody extends ResponseBody {
private Handler mHandler = new Handler(Looper.getMainLooper());
private ResponseBody mResponseBody;
private OnDownloadListener mListener;
private ProgressInfo mInfo;
private BufferedSource mBufferedSource;
private boolean mDoProgress;
//传入进度，以及监听对象
public WrapResponseBody(ResponseBody responseBody, ProgressInfo info, OnDownloadListener listener) {
    mResponseBody = responseBody;
    mInfo = info;
    mListener = listener;
}

@Nullable
@Override
public MediaType contentType() {
    //接口方法，返回类型
    return mResponseBody.contentType();
}

@Override
public long contentLength() {
    
    long contentLength = mResponseBody.contentLength();
    //gzip压缩格式会返回-1，目前处理是在请求头信息指定("Accept-Encoding","identity")表示不压缩
    if (contentLength == -1) {
        mDoProgress = false;
        mHandler.post(new Runnable() {
            @Override
            public void run() {
               //切换线程，进行失败回调
                mListener.onDownLoadGetContentLengthFail(mInfo);
            }
        });
    } else {
        mDoProgress = true;
    }
    return contentLength;
}

@Override
public BufferedSource source() {
    //WrapSource（继承ForwardingSource，ForwardingSource实现了Source接口）
    if (mBufferedSource == null) {
        mInfo.setContentLength(contentLength());
         //传入参数，读取具体进度信息，并回调 
        WrapSource wrapSource = new WrapSource(mResponseBody.source(), mInfo, mListener,mDoProgress);
        mBufferedSource = Okio.buffer(wrapSource);
    }
    return mBufferedSource;
}
}

--------------------------------------分割---------------------------------------   

//继承ResquestBody实现具体方法
public class WrapRequestBody extends RequestBody {
private RequestBody mRequestBody;
private OnUploadListener mListener;
private ProgressInfo mInfo;
private boolean mDoProgress;
private Handler mHandler = new Handler(Looper.getMainLooper());
 //传入进度，以及监听对象
public WrapRequestBody(RequestBody requestBody, ProgressInfo info, OnUploadListener listener) {
    mRequestBody = requestBody;
    mListener = listener;
    mInfo = info;
}


@Override
public MediaType contentType() {
    //接口方法，返回类型
    return mRequestBody.contentType();
}

@Override
public long contentLength() throws IOException {
    try {
        //上传内容长度，有异常走failWrok处理
        long l = mRequestBody.contentLength();
        mDoProgress = true;
        return l;
    } catch (IOException e) {
        e.printStackTrace();
        failWork();
        return -1;
    }
}
//进行失败处理
private void failWork() {
    mDoProgress = false;
    mHandler.post(new Runnable() {
        @Override
        public void run() {
            //切换线程，回调失败信息
            mListener.onUploadGetContentLengthFail(mInfo);
        }
    });
}

@Override
public void writeTo(BufferedSink sink) throws IOException {
    mInfo.setContentLength(contentLength());
    // WrapSink （继承ForwardingSink，ForwardingSink实现了Sink接口）
    ///传入参数，读取具体进度信息，并回调 
    WrapSink wrapSink = new WrapSink(sink, mInfo, mListener, mDoProgress);
    BufferedSink buffer = Okio.buffer(wrapSink);
    mRequestBody.writeTo(buffer);
    buffer.flush();
}
}

WrapSource、WrapSink相关实现

//继承ForwardingSource 实现具体方法
public class WrapSource extends ForwardingSource {
private Handler mHandler = new Handler(Looper.getMainLooper());
private Source mSource;
private ProgressInfo mInfo;
private OnDownloadListener mListener;
private boolean mDoProgress;

public WrapSource(Source source, ProgressInfo info, OnDownloadListener listener, boolean doProgress) {
    //传入源Source、进度信息、监听进度等信息。
    super(source);
    mSource = source;
    mInfo = info;
    mListener = listener;
   //传入是否继续执行回调boolean参数，如果之前执行有异常，则不再继续执行回调
    mDoProgress = doProgress;
}

@Override
public long read(Buffer sink, long byteCount) throws IOException {
    //获取具体进度信息，来到了熟悉的具体IO
    long read = super.read(sink, byteCount);
    if (read != -1) {
        long l = mInfo.getCurrentLength() + read;
        mInfo.setCurrentLength(l);
        mHandler.post(new Runnable() {
            @Override
            public void run() {
                if (mDoProgress) {
                    //切换到主线程，回调数据
                    mListener.onDownLoadProgress(mInfo);
                }
            }
        });
    }
    return read;
}
}

--------------------------------------分割---------------------------------------

//继承ForwardingSink 实现具体方法
public class WrapSink extends ForwardingSink {
private Handler mHandler = new Handler(Looper.getMainLooper());
public OnUploadListener mListener;
public ProgressInfo mInfo;
public boolean mDoProgress;

public WrapSink(Sink delegate, ProgressInfo info, OnUploadListener listener, boolean doProgress) {
    //传入源Source、进度信息、监听进度等信息。
    super(delegate);
    mInfo = info;
    mListener = listener;
     //传入是否继续执行回调boolean参数，如果之前执行有异常，则不再继续执行回调
    mDoProgress = doProgress;
}

@Override
public void write(Buffer source, long byteCount) throws IOException {
    super.write(source, byteCount);
    //获取具体进度信息，来到了熟悉的具体IO
    long l = mInfo.getCurrentLength() + byteCount;
    mInfo.setCurrentLength(l);
    mHandler.post(new Runnable() {
        @Override
        public void run() {
            if (mDoProgress) {
                //切换到主线程，回调数据
                mListener.onUpLoadProgress(mInfo);
            }
        }
    });
}
}

总结

以上就是具体的流程了，按照步骤其实很简单。大家了解下挺好的，我这边也封装好了具体的类库和Demo，大家可以直接依赖（查看README.md，使用简单）。
地址：https://github.com/HoldMyOwn/TNetProgress