OKHttp附件下载实现，进度监听

1.创建请求request

Request request = new Request.Builder().url(url).build();

2.获取response，由于是耗时操作，所以需要异步获取

new Thread(new Runnable() {
@Override
public void run() {
...
try {
Response response = okHttpClient.newCall(request).execute();
if (!response.isSuccessful() || response == null || response.body() == null) {
sendMessage(1, 0, 0, "");
} else {
//处理response
...
}
} catch (IOException e) {
e.printStackTrace();
sendMessage(1, 0, 0, "");
}
}
}).start();

3.处理获取的response，并进行进度监听

InputStream is = null;
byte[] buf = new byte[2048];
int len = 0;
FileOutputStream fos = null;
try {
is = response.body().byteStream();
int last = 0;
final long total = response.body().contentLength();
long sum = 0;
fos = new FileOutputStream(new File(apkPath));
while ((len = is.read(buf)) != -1) {
sum += len;
fos.write(buf, 0, len);
int now = (int) (sum * 100 / total);
if (last < now) {
LogUtils.d("current:" + last + ";total:" + 100);
sendMessage(3, last, 100, "");
last = now;
}
}
fos.flush();
sendMessage(2, 0, 0, "");
} catch (IOException e) {
e.printStackTrace();
sendMessage(1, 0, 0, "");
} finally {
try {
if (is != null) {
is.close();
}
} catch (IOException e) {
e.printStackTrace();
}
try {
if (fos != null) {
fos.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}

4.通知主线程进行相应的处理

public void sendMessage(int what, long current, long total, String msg) {
Message message = Message.obtain();
message.what = what;
message.arg1 = (int) current;
message.arg2 = (int) total;
message.obj = msg;
handler.sendMessage(message);
}
private Handler handler = new Handler() {
@Override
public void handleMessage(Message msg) {
super.handleMessage(msg);
switch (msg.what) {
case 1:
//下载失败
...
break;
case 2:
//下载成功
...
break;
case 3:
//下载进度
int current = msg.arg1;
int total = msg.arg2;
...
break;
}
}
};