ProgressResponseBody.java

package licola.demo.com.huabandemo.HttpUtils;

import java.io.IOException;

import licola.demo.com.huabandemo.API.OnProgressResponseListener;
import okhttp3.MediaType;
import okhttp3.ResponseBody;
import okio.Buffer;
import okio.BufferedSource;
import okio.ForwardingSource;
import okio.Okio;
import okio.Source;

/**
 * Created by LiCola on  2016/05/12  15:37
 * ResponseBody响应体的包装类
 * 主要功能是添加接口回调进度
 * 方法来自 https://github.com/square/okhttp/blob/master/samples%2Fguide%2Fsrc%2Fmain%2Fjava%2Fokhttp3%2Frecipes%2FProgress.java
 */
public class ProgressResponseBody extends ResponseBody {
    private static final String TAG = "ProgressResponseBody";
    //实际的待包装响应体
    private final ResponseBody responseBody;
    //进度回调接口
    private final OnProgressResponseListener progressListener;
    //包装完成的BufferedSource
    private BufferedSource bufferedSource;

    /**
     * 构造函数 依赖注入
     *
     * @param responseBody     待包装的响应体
     * @param progressListener 回调接口
     */
    public ProgressResponseBody(ResponseBody responseBody, OnProgressResponseListener progressListener) {
        this.responseBody = responseBody;
        this.progressListener = progressListener;
    }

    /**
     * 重写调用实际的响应体的contentType
     *
     * @return MediaType
     */
    @Override
    public MediaType contentType() {
        return responseBody.contentType();
    }

    /**
     * 重写调用实际的响应体的contentLength
     *
     * @return contentLength
     * @throws IOException 异常
     */
    @Override
    public long contentLength() {
        return responseBody.contentLength();
    }

    /**
     * 重写进行包装source
     *
     * @return BufferedSource
     * @throws IOException 异常
     */
    @Override
    public BufferedSource source() {
        if (bufferedSource == null) {
            bufferedSource = Okio.buffer(source(responseBody.source()));
        }
        return bufferedSource;
    }

    private Source source(Source source) {
        return new ForwardingSource(source) {
            long totalBytesRead = 0L;

            @Override
            public long read(Buffer sink, long byteCount) throws IOException {
                long bytesRead = super.read(sink, byteCount);
                // read() returns the number of bytes read, or -1 if this source is exhausted.
                totalBytesRead += bytesRead != -1 ? bytesRead : 0;

                progressListener.onResponseProgress(totalBytesRead, responseBody.contentLength(), bytesRead == -1);
                return bytesRead;
            }
        };
    }
}