OkHttp是比較火的網(wǎng)絡(luò)框架，它支持同步與異步請(qǐng)求，支持緩存，可以攔截，更方便下載大文件與上傳文件的操作。下面我們用OkHttp來下載文件并帶進(jìn)度條！
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相關(guān)資料：
官網(wǎng)地址：http://square.github.io/okhttp/
github源碼地址：https://github.com/square/okhttp
一、服務(wù)器端簡(jiǎn)單搭建
可以參考搭建本地Tomcat服務(wù)器及相關(guān)配置 這篇文章。
新建項(xiàng)目OkHttpServer，在WebContent目錄下新建downloadfile目錄，將要下載的jpg文件放在項(xiàng)目下。如下圖：
啟動(dòng)服務(wù)器，文件下載地址為http://localhost:8080/OkHttpServer/download/2.jpg 。這樣我們服務(wù)器就搭好了。
二、Android端
下面我們進(jìn)入正題。
1.build.gradle的dependencies配置如下
compile 'com.android.support:appcompat-v7:24.1.1' compile 'com.squareup.okhttp3:okhttp:3.2.0' compile 'com.squareup.okio:okio:1.7.0'
2.activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
3.編寫OkHttpUtil如下：
重慶分公司
重慶分公司
private static OkHttpClient okHttpClient = new OkHttpClient.Builder().connectTimeout(10000, TimeUnit.MILLISECONDS)
.readTimeout(10000,TimeUnit.MILLISECONDS)
.writeTimeout(10000,TimeUnit.MILLISECONDS).build();
//下載文件方法
public static void downloadFile(String url, final ProgressListener listener, Callback callback){
//增加攔截器
OkHttpClient client = okHttpClient.newBuilder().addNetworkInterceptor(new Interceptor() {
@Override
public Response intercept(Chain chain) throws IOException {
Response response = chain.proceed(chain.request());
return response.newBuilder().body(new ProgressResponseBody(response.body(),listener)).build();
}
}).build();
Request request = new Request.Builder().url(url).build();
client.newCall(request).enqueue(callback);
}
4.上面代碼中的ProgressResponseBody是自己編寫的類，ProgressListener 是監(jiān)聽的接口：
ProgressListener 接口
public interface ProgressListener {
//已完成的 總的文件長(zhǎng)度 是否完成
void onProgress(long currentBytes, long contentLength, boolean done);
}
ProgressResponseBody繼承ResponseBody ，返回監(jiān)聽進(jìn)度
public class ProgressResponseBody extends ResponseBody {
public static final int UPDATE = 0x01;
public static final String TAG = ProgressResponseBody.class.getName();
private ResponseBody responseBody;
private ProgressListener mListener;
private BufferedSource bufferedSource;
private Handler myHandler;
public ProgressResponseBody(ResponseBody body, ProgressListener listener) {
responseBody = body;
mListener = listener;
if (myHandler==null){
myHandler = new MyHandler();
}
}
/**
* 將進(jìn)度放到主線程中顯示
*/
class MyHandler extends Handler {
public MyHandler() {
super(Looper.getMainLooper());
}
@Override
public void handleMessage(Message msg) {
switch (msg.what){
case UPDATE:
ProgressModel progressModel = (ProgressModel) msg.obj;
//接口返回
if (mListener!=null)mListener.onProgress(progressModel.getCurrentBytes(),progressModel.getContentLength(),progressModel.isDone());
break;
}
}
}
@Override
public MediaType contentType() {
return responseBody.contentType();
}
@Override
public long contentLength() {
return responseBody.contentLength();
}
@Override
public BufferedSource source() {
if (bufferedSource==null){
bufferedSource = Okio.buffer(mySource(responseBody.source()));
}
return bufferedSource;
}
private Source mySource(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);
totalBytesRead +=bytesRead!=-1?bytesRead:0;
//發(fā)送消息到主線程，ProgressModel為自定義實(shí)體類
Message msg = Message.obtain();
msg.what = UPDATE;
msg.obj = new ProgressModel(totalBytesRead,contentLength(),totalBytesRead==contentLength());
myHandler.sendMessage(msg);
return bytesRead;
}
};
}
}
5.MainActivity的代碼：
public class MainActivity extends AppCompatActivity implements View.OnClickListener{
public static final String TAG = MainActivity.class.getName();
private ProgressBar download_progress;
private TextView download_text;
public static String basePath = Environment.getExternalStorageDirectory().getAbsolutePath() + "/okhttp";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
download_progress = (ProgressBar) findViewById(R.id.download_progress);
download_text = (TextView) findViewById(R.id.download_text);
findViewById(R.id.ok_download).setOnClickListener(this);
}
@Override
public void onClick(View view) {
switch (view.getId()){
case R.id.ok_download:
String url = "http://192.168.0.104:8080/OkHttpServer/download/2.jpg";
final String fileName = url.split("/")[url.split("/").length - 1];
Log.i(TAG, "fileName==" + fileName);
OkHttpUtil.downloadFile(url, new ProgressListener() {
@Override
public void onProgress(long currentBytes, long contentLength, boolean done) {
Log.i(TAG, "currentBytes==" + currentBytes + "==contentLength==" + contentLength + "==done==" + done);
int progress = (int) (currentBytes * 100 / contentLength);
download_progress.setProgress(progress);
download_text.setText(progress + "%");
}
}, new Callback() {
@Override
public void onFailure(Call call, IOException e) {
}
@Override
public void onResponse(Call call, Response response) throws IOException {
if (response != null) {
InputStream is = response.body().byteStream();
FileOutputStream fos = new FileOutputStream(new File(basePath + "/" + fileName));
int len = 0;
byte[] buffer = new byte[2048];
while (-1 != (len = is.read(buffer))) {
fos.write(buffer, 0, len);
}
fos.flush();
fos.close();
is.close();
}
}
});
break;
}
}
}
6.最后不要忘了添加權(quán)限：
源碼下載
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