[Android开发] 使用okhttp下载文件(带监听)

package com.minstone.mdoctor.tool.net;

import android.os.Handler;
import android.os.Looper;

import com.minstone.util.LogUtil;
import com.squareup.okhttp.Call;
import com.squareup.okhttp.Callback;
import com.squareup.okhttp.OkHttpClient;
import com.squareup.okhttp.Request;
import com.squareup.okhttp.Response;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;

import javax.net.ssl.SSLContext;
import javax.net.ssl.TrustManager;

import static com.minstone.util.FileAccessor.getFileName;

/**
* Created by LITP on 2016/9/26.
*/

public class DownloadManager {

public DownloadManager() {
mDelivery = new Handler(Looper.getMainLooper());
}

private Handler mDelivery;     //主线程返回

private Call downCall;         //下载的call

private static OkHttpClient mOkHttpClient;

private static DownloadManager mInstance;    //单例

public static DownloadManager getInstance() {
if (mInstance == null) {
synchronized (OkHttpManager.class) {
if (mInstance == null) {
mInstance = new DownloadManager();
}
}
}
return mInstance;
}

//synchronized修饰的静态方法锁定的是这个类的所有对象,保证在同一时刻最多只有一个线程执行该段代码
public synchronized  OkHttpClient getOkHttpClient() {
if (null == mOkHttpClient) {
try {
mOkHttpClient = newOkHttpClient();
} catch (Exception e) {
e.printStackTrace();
}
}
return mOkHttpClient;
}

/**
* 创建okhttp
*
* @return
* @throws Exception
*/
private OkHttpClient newOkHttpClient() throws Exception {

//创建okHttpClient对象
OkHttpClient mOkHttpClient = new OkHttpClient();

TrustManager tm = new OkHttpManager.myTrustManager();
SSLContext sslContext = SSLContext.getInstance("TLS");
sslContext.init(null, new TrustManager[]{tm}, null);

mOkHttpClient.setSslSocketFactory(sslContext.getSocketFactory());

return mOkHttpClient;
}

/**
* 异步下载文件
*
* @param url         文件的下载地址
* @param destFileDir 本地文件存储的文件夹
* @param callback
*/
private void okHttpDownload(final String url, final String destFileDir, final ResultCallback callback) {

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

downCall = getOkHttpClient().newCall(request);
downCall.enqueue(new Callback() {
@Override
public void onFailure(final Request request, final IOException e) {
sendFailedStringCallback(request, e, callback);
}

@Override
public void onResponse(Response response) {
InputStream is = null;
byte[] buf = new byte[2048];
int len = 0;
FileOutputStream fos = null;
try {
double current = 0;
double total = response.body().contentLength();

is = response.body().byteStream();
File file = new File(destFileDir, getFileName(url));
fos = new FileOutputStream(file);
while ((len = is.read(buf)) != -1) {
current += len;
fos.write(buf, 0, len);
LogUtil.w("download current------>" + current);
sendProgressCallBack(total, current, callback);
}
fos.flush();
//如果下载文件成功，第一个参数为文件的绝对路径
sendSuccessResultCallback(file.getAbsolutePath(), callback);
} catch (IOException e) {
sendFailedStringCallback(response.request(), e, callback);
} finally {
try {
if (is != null) is.close();
} catch (IOException e) {
e.printStackTrace();
}
try {
if (fos != null) fos.close();
} catch (IOException e) {
e.printStackTrace();
}
}

}
});
}

//下载失败ui线程回调
private void sendFailedStringCallback(final Request request, final Exception e, final ResultCallback callback) {
mDelivery.post(new Runnable() {
@Override
public void run() {
if (callback != null)
callback.onError(request, e);
}
});
}

//下载成功ui线程回调
private void sendSuccessResultCallback(final Object object, final ResultCallback callback) {
mDelivery.post(new Runnable() {
@Override
public void run() {
if (callback != null) {
callback.onResponse(object);
}
}
});
}

//下载回调接口
public static abstract class ResultCallback<T> {

//下载错误
public abstract void onError(Request request, Exception e);

//下载成功
public abstract void onResponse(T response);

//下载进度
public abstract void onProgress(double total, double current);
}

/**
* 进度信息ui线程回调
*
* @param total    总计大小
* @param current  当前进度
* @param callBack
* @param <T>
*/
private <T> void sendProgressCallBack(final double total, final double current, final ResultCallback<T> callBack) {
mDelivery.post(new Runnable() {
@Override
public void run() {
if (callBack != null) {
callBack.onProgress(total, current);
}
}
});
}

/*  下面为对外开放接口 */

/**
* 下载文件
*
* @param url 文件链接
* @param destDir 下载保存地址
* @param callback 回调
*/
public static void downloadFile(String url, String destDir, ResultCallback callback) {
getInstance().okHttpDownload(url, destDir, callback);
}

/**
* 取消下载
*/
public static void cancleDown(){
getInstance().downCall.cancel();
}

}

private void startDown(){
String apkUrl = "apk下载的链接";
String fileUrl = Environment.getExternalStorageDirectory().getAbsolutePath();
DownloadManager.downloadFile(apkUrl,fileUrl,new DownloadCallBack());
}

//监听类
class DownloadCallBack extends DownloadManager.ResultCallback {

@Override
public void onError(Request request, Exception e) {
//下载失败返回
}

@Override
public void onResponse(Object response) {
//下载成功返回
}

@Override
public void onProgress(double total, double current) {
//进度返回
}
}