Retrofit+RxJava实现带进度条的文件下载

PackageManager packageManager = mActivity.getPackageManager();

 PackageInfo packageInfo = null;

 try {
 packageInfo = packageManager.getPackageInfo(mActivity.getPackageName(), 0);
 } catch (PackageManager.NameNotFoundException e) {
 e.printStackTrace();
 }

 String versionName = packageInfo.versionName;

public class ProgressResponseBody extends ResponseBody {

 private ResponseBody responseBody;

 private ProgressListener progressListener;

 private BufferedSource bufferedSource;


 public ProgressResponseBody(ResponseBody responseBody,ProgressListener progressListener){

 this.responseBody=responseBody;

 this.progressListener=progressListener;
 }


 @Override
 public MediaType contentType() {

 return responseBody.contentType();
 }

 @Override
 public long contentLength() {

 return responseBody.contentLength();
 }

 @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 {
 //当前读取字节数
 long bytesRead = super.read(sink, byteCount);
 //增加当前读取的字节数，如果读取完成了bytesRead会返回-1
 totalBytesRead += bytesRead != -1 ? bytesRead : 0;
 //回调，如果contentLength()不知道长度，会返回-1

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

public class ProgressInterceptor implements Interceptor {

 @Override
 public Response intercept(Chain chain) throws IOException {

 Response response=chain.proceed(chain.request());
 return response.newBuilder().body(new ProgressResponseBody(response.body(),progressListener)).build();
 }
 static final ProgressListener progressListener=new ProgressListener() {
 @Override
 public void onProgress(long progress, long total, long speed, boolean done) {

 Log.i("log","progress="+progress+"total="+total);
 }
 };
}

 //为Okhttp设置拦截器
 OkHttpClient client = new OkHttpClient.Builder()
 .addNetworkInterceptor(new Interceptor() {
 @Override public Response intercept(Chain chain) throws IOException {
  Response originalResponse = chain.proceed(chain.request());
  return originalResponse.newBuilder()
  .body(new ProgressResponseBody(originalResponse.body(), progressListener))
  .build();
 }
 })
 .build();

 //进度回调监听
 ProgressListener progressListener=new ProgressListener() {
 @Override
 public void onProgress(long progress, long total, long speed, boolean done) {

 Message message=new Message();

 message.obj=new AmallLoadBean(progress,total);

 progressHandler.sendMessage(message);
 }
 };

//处理下载版本进度
 public class ProgressHandler extends Handler{

 private WeakReference<Activity> mActivityWeakReference;
 public ProgressHandler(Activity activity){

 mActivityWeakReference=new WeakReference<Activity>(activity);

 }

 @Override
 public void handleMessage(Message msg) {
 if(mActivityWeakReference.get()!=null){
 AmallLoadBean amallLoadBean= (AmallLoadBean) msg.obj;
 long progress=amallLoadBean.getProgress();
 long total=amallLoadBean.getTotal();
 float cp=(float)progress/(float)total;

 }
 }
 }

observable.subscribeOn(Schedulers.io())
 .observeOn(Schedulers.io())
 .doOnNext(new Action1<ResponseBody>() {
  @Override
  public void call(ResponseBody responseBody) {

  saveFiles(responseBody);
  }
 })
 .observeOn(AndroidSchedulers.mainThread())
 .subscribe(new Observer<ResponseBody>() {
  @Override
  public void onCompleted() {
  installApk();

  }

  @Override
  public void onError(Throwable e) {

  ToastUtils.getInstance().showToast("请到应用市场下载最新版本");
  }

  @Override
  public void onNext(ResponseBody responseBody) {

  }
 });
 }

/**
 * 保存文件
 */
 public void saveFiles(ResponseBody responseBody){

 InputStream inputStream = null;

 FileOutputStream fileOutputStream = null;

 byte[] buffer=new byte[2048];

 int len;

 File file=new File(saveFileName);

 if(!file.exists()){

 file.mkdirs();
 }

 try {
 inputStream=responseBody.byteStream();

 fileOutputStream=new FileOutputStream(file);

 while ((len=inputStream.read(buffer))!=-1){

 fileOutputStream.write(buffer,0,len);
 }

 inputStream.close();

 fileOutputStream.close();

 } catch (Exception e) {
 e.printStackTrace();
 }


 }

 /**
 * 安装apk
 *
 */
 private void installApk() {
 File apkfile = new File(saveFileName);
 if (!apkfile.exists()) {
 return;
 }
 //判断版本号

 if(Build.VERSION.SDK_INT>=Build.VERSION_CODES.N){
 Uri apkUri = FileProvider.getUriForFile(activity, "******.fileprovider", apkfile);
 Intent install = new Intent(Intent.ACTION_VIEW);
 install.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
 //添加这一句表示对目标应用临时授权该Uri所代表的文件
 install.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
 install.setDataAndType(apkUri, "application/vnd.android.package-archive");
 activity.startActivity(install);

 }else{

 Intent i = new Intent(Intent.ACTION_VIEW);
 i.setDataAndType(Uri.parse("file://" + apkfile.toString()), "application/vnd.android.package-archive");
 activity.startActivity(i);
 }

 }