@Streaming
@GET
Call<ResponseBody> downloadSong(@Url String url);
上述代码使用Retrofit异步下载文件。我想获取下载进度,如果有暂停/恢复的可能性,请回答这个问题。最终我得到了答案。
为此,我们需要使用rxjava和retrofit。
DownloadProgressListener.java
public interface DownloadProgressListener {
void update(long bytesRead, long contentLength, boolean done);
}
DownloadProgressResponseBody.java
public class DownloadProgressResponseBody extends ResponseBody {
private ResponseBody responseBody;
private DownloadProgressListener progressListener;
private BufferedSource bufferedSource;
public DownloadProgressResponseBody(ResponseBody responseBody,
DownloadProgressListener 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 {
long bytesRead = super.read(sink, byteCount);
// read() returns the number of bytes read, or -1 if this source is exhausted.
totalBytesRead += bytesRead != -1 ? bytesRead : 0;
if (null != progressListener) {
progressListener.update(totalBytesRead, responseBody.contentLength(), bytesRead == -1);
}
return bytesRead;
}
};
}
}
DownloadProgressInterceptor.java
public class DownloadProgressInterceptor implements Interceptor {
private DownloadProgressListener listener;
public DownloadProgressInterceptor(DownloadProgressListener listener) {
this.listener = listener;
}
@Override
public Response intercept(Chain chain) throws IOException {
Response originalResponse = chain.proceed(chain.request());
return originalResponse.newBuilder()
.body(new DownloadProgressResponseBody(originalResponse.body(), listener))
.build();
}
}
下载.java
public class Download implements Parcelable {
private int progress;
private long currentFileSize;
private long totalFileSize;
public int getProgress() {
return progress;
}
public void setProgress(int progress) {
this.progress = progress;
}
public long getCurrentFileSize() {
return currentFileSize;
}
public void setCurrentFileSize(long currentFileSize) {
this.currentFileSize = currentFileSize;
}
public long getTotalFileSize() {
return totalFileSize;
}
public void setTotalFileSize(long totalFileSize) {
this.totalFileSize = totalFileSize;
}
@Override
public int describeContents() {
return 0;
}
@Override
public void writeToParcel(Parcel dest, int flags) {
dest.writeInt(this.progress);
dest.writeLong(this.currentFileSize);
dest.writeLong(this.totalFileSize);
}
public Download() {
}
protected Download(Parcel in) {
this.progress = in.readInt();
this.currentFileSize = in.readLong();
this.totalFileSize = in.readLong();
}
public static final Parcelable.Creator<Download> CREATOR = new Parcelable.Creator<Download>() {
@Override
public Download createFromParcel(Parcel source) {
return new Download(source);
}
@Override
public Download[] newArray(int size) {
return new Download[size];
}
};
}
DownloadService.java
public interface DownloadService {
@Streaming
@GET
Observable<ResponseBody> download(@Url String url);
}
DownloadAPI.java
public class DownloadAPI {
private static final String TAG = "DownloadAPI";
private static final int DEFAULT_TIMEOUT = 15;
public Retrofit retrofit;
public DownloadAPI(String url, DownloadProgressListener listener) {
DownloadProgressInterceptor interceptor = new DownloadProgressInterceptor(listener);
OkHttpClient client = new OkHttpClient.Builder()
.addInterceptor(interceptor)
.retryOnConnectionFailure(true)
.connectTimeout(DEFAULT_TIMEOUT, TimeUnit.SECONDS)
.build();
retrofit = new Retrofit.Builder()
.baseUrl(url)
.client(client)
.addCallAdapterFactory(RxJavaCallAdapterFactory.create())
.build();
}
public void downloadAPK(@NonNull String url, final File file, Subscriber subscriber) {
Log.d(TAG, "downloadAPK: " + url);
retrofit.create(DownloadService.class)
.download(url)
.subscribeOn(Schedulers.io())
.unsubscribeOn(Schedulers.io())
.map(new Func1<ResponseBody, InputStream>() {
@Override
public InputStream call(ResponseBody responseBody) {
return responseBody.byteStream();
}
})
.observeOn(Schedulers.computation())
.doOnNext(new Action1<InputStream>() {
@Override
public void call(InputStream inputStream) {
try {
FileUtils.writeFile(inputStream, file);
} catch (IOException e) {
e.printStackTrace();
throw new CustomizeException(e.getMessage(), e);
}
}
})
.observeOn(AndroidSchedulers.mainThread())
.subscribe(subscriber);
}
}
使用方法
DownloadProgressListener listener = new DownloadProgressListener() {
@Override
public void update(long bytesRead, long contentLength, boolean done) {
Download download = new Download();
download.setTotalFileSize(contentLength);
download.setCurrentFileSize(bytesRead);
int progress = (int) ((bytesRead * 100) / contentLength);
download.setProgress(progress);
sendNotification(download);
}
};
File outputFile = new File(Environment.getExternalStoragePublicDirectory
(Environment.DIRECTORY_DOWNLOADS), "file.apk");
String baseUrl = StringUtils.getHostName(apkUrl);
new DownloadAPI(baseUrl, listener).downloadAPK(apkUrl, outputFile, new Subscriber() {
@Override
public void onCompleted() {
downloadCompleted();
}
@Override
public void onError(Throwable e) {
e.printStackTrace();
downloadCompleted();
Log.e(TAG, "onError: " + e.getMessage());
}
@Override
public void onNext(Object o) {
}
});
我刚刚使用了@Jan发布的代码,但是我遇到了一个问题,它不能下载并且只有一次回调,经过多次尝试,我找到了解决方案:
OkHttpClient client = new OkHttpClient.Builder()
// .addInterceptor(interceptor)
.addNetworkInterceptor(interceptor)
只需将拦截器更改为networkInterceptor,它就可以正常运行!祝你好运!