通过Retrofit 2上传图像时是否可以显示进度条？
我目前正在使用Retrofit 2 ，我想在我的服务器上传一些照片。 我知道，旧版本使用TypedFile类来上传。 如果我们想使用进度条，我们应该重写TypedFile类中的writeTo方法。
使用retrofit 2库时可以显示进度吗？
首先，你应该使用Retrofit 2版本等于或高于2.0 beta2。 二，创建新类扩展RequestBody ：
public class ProgressRequestBody extends RequestBody { private File mFile; private String mPath; private UploadCallbacks mListener; private static final int DEFAULT_BUFFER_SIZE = 2048; public interface UploadCallbacks { void onProgressUpdate(int percentage); void onError(); void onFinish(); } public ProgressRequestBody(final File file, final UploadCallbacks listener) { mFile = file; mListener = listener; } @Override public MediaType contentType() { // i want to upload only images return MediaType.parse("image/*"); } @Override public long contentLength() throws IOException { return mFile.length(); } @Override public void writeTo(BufferedSink sink) throws IOException { long fileLength = mFile.length(); byte[] buffer = new byte[DEFAULT_BUFFER_SIZE]; FileInputStream in = new FileInputStream(mFile); long uploaded = 0; try { int read; Handler handler = new Handler(Looper.getMainLooper()); while ((read = in.read(buffer)) != -1) { // update progress on UI thread handler.post(new ProgressUpdater(uploaded, fileLength)); uploaded += read; sink.write(buffer, 0, read); } } finally { in.close(); } } private class ProgressUpdater implements Runnable { private long mUploaded; private long mTotal; public ProgressUpdater(long uploaded, long total) { mUploaded = uploaded; mTotal = total; } @Override public void run() { mListener.onProgressUpdate((int)(100 * mUploaded / mTotal)); } } }
三，创建界面
@Multipart @POST("/upload") Call<JsonObject> uploadImage(@Part MultipartBody.Part file);
现在你可以获得你的上传进度。
在你的activity （或fragment ）中：
class MyActivity extends AppCompatActivity implements ProgressRequestBody.UploadCallbacks { ProgressBar progressBar; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); progressBar = findViewById(R.id.progressBar); ProgressRequestBody fileBody = new ProgressRequestBody(file, this); MultipartBody.Part filePart = MultipartBody.Part.createFormData("image", file.getName(), fileBody); Call<JsonObject> request = RetrofitClient.uploadImage(filepart); request.enqueue(new Callback<JsonObject>{...}); } @Override public void onProgressUpdate(int percentage) { // set current progress progressBar.setProgress(percentage); } @Override public void onError() { // do something on error } @Override public void onFinish() { // do something on upload finished // for example start next uploading at queue progressBar.setProgress(100); } }
以下是如何使用简单的POST而不是Multipart处理上传文件的进度。 多方检查@ Yariy的解决方案。 此外，此解决方案使用内容URI而不是直接文件引用。
RESTClient实现
@Headers({ "Accept: application/json", "Content-Type: application/octet-stream" }) @POST("api/v1/upload") Call<FileDTO> uploadFile(@Body RequestBody file);
ProgressRequestBody
public class ProgressRequestBody extends RequestBody { private static final String LOG_TAG = ProgressRequestBody.class.getSimpleName(); public interface ProgressCallback { public void onProgress(long progress, long total); } public static class UploadInfo { //Content uri for the file public Uri contentUri; // File size in bytes public long contentLength; } private WeakReference<Context> mContextRef; private UploadInfo mUploadInfo; private ProgressCallback mListener; private static final int UPLOAD_PROGRESS_BUFFER_SIZE = 8192; public ProgressRequestBody(Context context, UploadInfo uploadInfo, ProgressCallback listener) { mContextRef = new WeakReference<>(context); mUploadInfo = uploadInfo; mListener = listener; } @Override public MediaType contentType() { // NOTE: We are posting the upload as binary data so we don't need the true mimeType return MediaType.parse("application/octet-stream"); } @Override public void writeTo(BufferedSink sink) throws IOException { long fileLength = mUploadInfo.contentLength; byte[] buffer = new byte[UPLOAD_PROGRESS_BUFFER_SIZE]; InputStream in = in(); long uploaded = 0; try { int read; while ((read = in.read(buffer)) != -1) { mListener.onProgress(uploaded, fileLength); uploaded += read; sink.write(buffer, 0, read); } } finally { in.close(); } } /** * WARNING: You must override this function and return the file size or you will get errors */ @Override public long contentLength() throws IOException { return mUploadInfo.contentLength; } private InputStream in() throws IOException { InputStream stream = null; try { stream = getContentResolver().openInputStream(mUploadInfo.contentUri); } catch (Exception ex) { Log.e(LOG_TAG, "Error getting input stream for upload", ex); } return stream; } private ContentResolver getContentResolver() { if (mContextRef.get() != null) { return mContextRef.get().getContentResolver(); } return null; } }
要启动上传：
// Create a ProgressRequestBody for the file ProgressRequestBody requestBody = new ProgressRequestBody( getContext(), new UploadInfo(myUri, fileSize), new ProgressRequestBody.ProgressCallback() { public void onProgress(long progress, long total) { //Update your progress UI here //You'll probably want to use a handler to run on UI thread } } ); // Upload mRestClient.uploadFile(requestBody);
警告，如果您忘记重写contentLength（）函数，您可能会收到一些模糊的错误：
retrofit2.adapter.rxjava.HttpException: HTTP 503 client read error
要么
Write error: ssl=0xb7e83110: I/O error during system call, Broken pipe
要么
javax.net.ssl.SSLException: Read error: ssl=0x9524b800: I/O error during system call, Connection reset by peer
这些是RequestBody.writeTo（）被默认contentLength（）为-1的多次调用的结果。
无论如何，这花了很长时间弄清楚，希望它有帮助。
有用的链接： https ： //github.com/square/retrofit/issues/1217
修改尤里·Kolbasinskiy的使用rxjava和使用kotlin。 增加了一个同时使用HttpLoggingInterceptor的解决方法
class ProgressRequestBody : RequestBody { val mFile: File val ignoreFirstNumberOfWriteToCalls : Int constructor(mFile: File) : super(){ this.mFile = mFile ignoreFirstNumberOfWriteToCalls = 0 } constructor(mFile: File, ignoreFirstNumberOfWriteToCalls : Int) : super(){ this.mFile = mFile this.ignoreFirstNumberOfWriteToCalls = ignoreFirstNumberOfWriteToCalls } var numWriteToCalls = 0 protected val getProgressSubject: PublishSubject<Float> = PublishSubject.create<Float>() fun getProgressSubject(): Observable<Float> { return getProgressSubject } override fun contentType(): MediaType { return MediaType.parse("video/mp4") } @Throws(IOException::class) override fun contentLength(): Long { return mFile.length() } @Throws(IOException::class) override fun writeTo(sink: BufferedSink) { numWriteToCalls++ val fileLength = mFile.length() val buffer = ByteArray(DEFAULT_BUFFER_SIZE) val `in` = FileInputStream(mFile) var uploaded: Long = 0 try { var read: Int read = `in`.read(buffer) while (read != -1) { uploaded += read.toLong() sink.write(buffer, 0, read) read = `in`.read(buffer) // when using HttpLoggingInterceptor it calls writeTo and passes data into a local buffer just for logging purposes. // the second call to write to is the progress we actually want to track if (numWriteToCalls > ignoreFirstNumberOfWriteToCalls ) { val progress = (uploaded.toFloat() / fileLength.toFloat()) * 100f //prevent publishing too many updates, which slows upload, by checking if the upload has progressed by at least 1 percent if (progress - lastProgressPercentUpdate > 1 || progress == 100f) { // publish progress getProgressSubject.onNext(progress) lastProgressPercentUpdate = progress } } } } finally { `in`.close() } } companion object { private val DEFAULT_BUFFER_SIZE = 2048 }
}
一个示例视频上传界面
public interface Api { @Multipart @POST("/upload") Observable<ResponseBody> uploadVideo(@Body MultipartBody requestBody); }
一个示例函数发布视频：
fun postVideo(){ val api : Api = Retrofit.Builder() .client(OkHttpClient.Builder() //.addInterceptor(HttpLoggingInterceptor().setLevel(HttpLoggingInterceptor.Level.BODY)) .build()) .baseUrl("BASE_URL") .addCallAdapterFactory(RxJava2CallAdapterFactory.create()) .build() .create(Api::class.java) val videoPart = ProgressRequestBody(File(VIDEO_URI)) //val videoPart = ProgressRequestBody(File(VIDEO_URI), 1) //HttpLoggingInterceptor workaround val requestBody = MultipartBody.Builder() .setType(MultipartBody.FORM) .addFormDataPart("example[name]", place.providerId) .addFormDataPart("example[video]","video.mp4", videoPart) .build() videoPart.getProgressSubject() .subscribeOn(Schedulers.io()) .subscribe { percentage -> Log.i("PROGRESS", "${percentage}%") } var postSub : Disposable?= null postSub = api.postVideo(requestBody) .subscribeOn(Schedulers.io()) .observeOn(AndroidSchedulers.mainThread()) .subscribe({ r -> },{e-> e.printStackTrace() postSub?.dispose(); }, { Toast.makeText(this,"Upload SUCCESS!!",Toast.LENGTH_LONG).show() postSub?.dispose(); }) }
我更新进度栏onProgressUpdate。 这段代码可以获得更好的性能。
@Override public void writeTo(BufferedSink sink) throws IOException { long fileLength = mFile.length(); byte[] buffer = new byte[DEFAULT_BUFFER_SIZE]; FileInputStream in = new FileInputStream(mFile); long uploaded = 0; try { int read; Handler handler = new Handler(Looper.getMainLooper()); int num = 0; while ((read = in.read(buffer)) != -1) { int progress = (int) (100 * uploaded / fileLength); if( progress > num + 1 ){ // update progress on UI thread handler.post(new ProgressUpdater(uploaded, fileLength)); num = progress; } uploaded += read; sink.write(buffer, 0, read); } } finally { in.close(); } }
据我可以在这篇文章中看到，没有关于图像上传进度响应的更新，你仍然必须override writeTo方法， 如此回答中所示，通过使ProgressListener接口和使用TypedFile的子类来override writeTo方法。
所以，在使用改造2库时没有任何内置的方法来显示进度。
我试图使用上面的代码，但我发现UI被卡住了，所以我试着这个代码这是为我工作，或可能尝试使用此代码
@ luca992谢谢你的回答。 我已经在JAVA中实现了，现在它工作正常。
public class ProgressRequestBodyObservable extends RequestBody { File file; int ignoreFirstNumberOfWriteToCalls; int numWriteToCalls;`enter code here` public ProgressRequestBodyObservable(File file) { this.file = file; ignoreFirstNumberOfWriteToCalls =0; } public ProgressRequestBodyObservable(File file, int ignoreFirstNumberOfWriteToCalls) { this.file = file; this.ignoreFirstNumberOfWriteToCalls = ignoreFirstNumberOfWriteToCalls; } PublishSubject<Float> floatPublishSubject = PublishSubject.create(); public Observable<Float> getProgressSubject(){ return floatPublishSubject; } @Override public MediaType contentType() { return MediaType.parse("image/*"); } @Override public long contentLength() throws IOException { return file.length(); } @Override public void writeTo(BufferedSink sink) throws IOException { numWriteToCalls++; float fileLength = file.length(); byte[] buffer = new byte[2048]; FileInputStream in = new FileInputStream(file); float uploaded = 0; try { int read; read = in.read(buffer); float lastProgressPercentUpdate = 0; while (read != -1) { uploaded += read; sink.write(buffer, 0, read); read = in.read(buffer); // when using HttpLoggingInterceptor it calls writeTo and passes data into a local buffer just for logging purposes. // the second call to write to is the progress we actually want to track if (numWriteToCalls > ignoreFirstNumberOfWriteToCalls ) { float progress = (uploaded / fileLength) * 100; //prevent publishing too many updates, which slows upload, by checking if the upload has progressed by at least 1 percent if (progress - lastProgressPercentUpdate > 1 || progress == 100f) { // publish progress floatPublishSubject.onNext(progress); lastProgressPercentUpdate = progress; } } } } finally { in.close(); } } }
对于2.0.0 beta4上传文件没有正确实施
解析器源代码
@Documented @Target(PARAMETER) @Retention(RUNTIME) public @interface Part { String value(); String encoding() default "binary"; } // ##### okhttp3.Headers headers = okhttp3.Headers.of( "Content-Disposition", "form-data; name=\"" + part.value() + "\"", "Content-Transfer-Encoding", part.encoding());
并且没有办法通过注释添加文件名
所以我们使用这个hack来插入文件名
现在接口一定是
@Multipart @POST("some/method") Observable<Response<SomeClass>> UpdateUserPhoto( // RxJava @Part("token") RequestBody token, @Part("avatar\"; filename=\"avatar.png") RequestBody photo );
并在建立请求之后
Content-Disposition: form-data; name="avatar"; filename="avatar.png" Content-Transfer-Encoding: binary
RequestBody媒体类型的文件（图像）必须是
MediaType MEDIA_TYPE_IMAGE = MediaType.parse("image/*");
或者你选择的其他东西