OkHttp获取request请求进度

对于上传文件，经常需要获得文件的上传进度反馈给用户。使用OkHttp时，可以通过包装RequestBody来实现进度反馈的功能。代码如下

<pre name="code" class="java">/**
* OkHttp请求的进度反馈
* 上传文件可以得到上传进度
*/
public class ProgressRequestBody extends RequestBody {

private RequestBody requestBody;

private ProgressListener listener;

interface ProgressListener {
/**
* 请求进度回调
*
* @param len 已完成进度
* @param size 总大小
*/
void onProgress(long len, long size);
}

public ProgressRequestBody(RequestBody requestBody, ProgressListener listener) {
this.requestBody = requestBody;
this.listener = listener;
}

@Override
public MediaType contentType() {
return requestBody.contentType();
}

@Override
public void writeTo(BufferedSink bufferedSink) throws IOException {
if (listener != null) {
// 计算总长度
Buffer buffer = new Buffer();
requestBody.writeTo(buffer);
long size = buffer.size();
if (size == -1) {
return;
}

// 然后一次写2048大小的内容
int blockSize = 2048;
long writeSize = 0;
while (writeSize + blockSize < size) {
buffer.copyTo(bufferedSink.buffer(), writeSize, blockSize);
writeSize += blockSize;
listener.onProgress(writeSize, size);
}
buffer.copyTo(bufferedSink.buffer(), writeSize, size - writeSize);
bufferedSink.flush();
listener.onProgress(writeSize, size);
buffer.clear();
} else {
requestBody.writeTo(bufferedSink);
}
}
}

使用方式上传文件中使用,注意由于ProgressListener的进度回调不在UI线程，如需刷新UI，可用Handler发送进度到主线程再刷新界面

/**
* 上传文件
*
* @param url 上传url
* @param params 上传的其他参数
* @param files 上传文件列表
* @param listener 进度监听
* @return
* @throws IOException
*/
public Response upload(String url, Map<String, String> params, Map<String, String> files,
ProgressListener listener) throws IOException {
MultipartBuilder builder = new MultipartBuilder()
.type(MultipartBuilder.FORM);

//添加参数的文件
Iterator<Entry<String, String>> paramsIterator = params.entrySet().iterator();
while (paramsIterator.hasNext()) {
Entry<String, String> entry = paramsIterator.next();
String key = entry.getKey();
String val = entry.getValue();
builder.addFormDataPart(key, val);
}

//添加上传的文件
Iterator<Entry<String, String>> filesIterator = files.entrySet().iterator();
while (filesIterator.hasNext()) {
Entry<String, String> entry = filesIterator.next();
RequestBody requestBody = RequestBody
.create(MediaType.parse("application/octet-stream"), new File(entry.getValue()));
builder.addFormDataPart(entry.getKey(), entry.getValue(), requestBody);
}

RequestBody requestBody = builder.build();

ProgressRequestBody pdBody = new ProgressRequestBody(requestBody, listener);

final Request request = new Request.Builder().url(url).post(pdBody).build();

OkHttpClient client = getClient().clone();
client.setConnectTimeout(config.uploadConnectTimeout, TimeUnit.MILLISECONDS);
client.setReadTimeout(config.uploadReadTimeout, TimeUnit.MILLISECONDS);
client.setWriteTimeout(config.uploadWriteTimeout, TimeUnit.MILLISECONDS);
return client.newCall(request).execute();
}