java - 上传文件使用 HttpUrlConnection 时出错

Question

我有一个 Android 应用程序，我想从这个应用程序上传大图像(在本例中为 32MB)到 Spring Server，但是我得到了 java.net.SocketException: sendto failed: EPIPE (Broken pipe) 错误。

我用这个方法:

public static void setPicture(User user, Picture picture, HavePicture havePicture, File file) {
    try {
        URL url = new URL(Request.BASE_URL + Request.BASE_PATH + Request.GAME_SYSTEM_PATH + Request.SET_PICTURE_PATH);
        HttpURLConnection connection = (HttpURLConnection) url.openConnection();
        connection.setUseCaches(false);
        connection.setDoOutput(true); // indicates POST method
        connection.setDoInput(true);
        connection.setRequestProperty("Content-Type", "multipart/form-data; boundary=" + boundary);
        connection.setRequestProperty("User-Agent", "CodeJava Agent");
        connection.setRequestProperty("Test", "Bonjour");

        //load file with multi small pices not one lage pice good to use large filse
        connection.setChunkedStreamingMode(1024);

        OutputStream outputStream = connection.getOutputStream();
        PrintWriter writer = new PrintWriter(new OutputStreamWriter(outputStream, Request.CHARSET), true);

        addFormField(writer, Request.PARAM_USER, Json.toJson(user));
        addFormField(writer, Request.PARAM_PICTURE, Json.toJson(picture));
        addFormField(writer, Request.PARAM_HAVE_PICTURE, Json.toJson(havePicture));
        addFilePart(writer, outputStream, Request.PARAM_FILE, file);

        StringBuffer response = new StringBuffer();

        writer.append(LINE_FEED).flush();
        writer.append("--" + boundary + "--").append(LINE_FEED);
        writer.close();
        // checks server's status code first
        int status = connection.getResponseCode();
        if (status == HttpURLConnection.HTTP_OK) {
            BufferedReader reader = new BufferedReader(new InputStreamReader(
                    connection.getInputStream()));
            String line = null;
            while ((line = reader.readLine()) != null) {
                response.append(line);
            }
            reader.close();
            connection.disconnect();
        } else {
            throw new IOException("Server returned non-OK status: " + status);
        }

        String a =  response.toString();
        System.out.println(a);

    } catch (UnsupportedEncodingException e) {
        e.printStackTrace();
    } catch (MalformedURLException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

参数:user 、picture 和 havePicture 是我想用大图像发送给它们的一些对象，这个方法实际上可以处理至少 1MB 的小图像。

这里是其余的方法:

private static void addFormField(PrintWriter writer, String name, String value) {
    writer.append("--" + boundary).append(LINE_FEED);
    writer.append("Content-Disposition: form-data; name=\"" + name + "\"").append(LINE_FEED);
    writer.append("Content-Type: text/plain; charset=" + Request.CHARSET).append(LINE_FEED);
    writer.append(LINE_FEED);
    writer.append(value).append(LINE_FEED);
    writer.flush();
}

用于图像文件:

private static void addFilePart(PrintWriter writer,OutputStream outputStream, String fieldName, File uploadFile) throws IOException {
    String fileName = uploadFile.getName();
    writer.append("--" + boundary).append(LINE_FEED);
    writer.append("Content-Disposition: form-data; name=\"" + fieldName + "\"; filename=\"" + fileName + "\"").append(LINE_FEED);
    writer.append("Content-Type: "+URLConnection.guessContentTypeFromName(fileName)).append(LINE_FEED);
    writer.append("Content-Transfer-Encoding: binary").append(LINE_FEED);

    FileInputStream inputStream = new FileInputStream(uploadFile);

    writer.append("Content-length: "+inputStream.available()).append(LINE_FEED);
    System.out.println("- - "+"Content-length: "+inputStream.available());
    writer.append(LINE_FEED);
    writer.flush();


    byte[] buffer = new byte[4096];
    int bytesRead = -1;
    while ((bytesRead = inputStream.read(buffer)) != -1) {
        outputStream.write(buffer, 0, bytesRead);
    }
    outputStream.flush();
    inputStream.close();

    writer.append(LINE_FEED);
    writer.flush();
}

这是我完成的错误:

java.net.SocketException: sendto failed: EPIPE (Broken pipe) at libcore.io.IoBridge.maybeThrowAfterSendto(IoBridge.java:586) at libcore.io.IoBridge.sendto(IoBridge.java:555) at java.net.PlainSocketImpl.write(PlainSocketImpl.java:520) at java.net.PlainSocketImpl.access$100(PlainSocketImpl.java:43) at java.net.PlainSocketImpl$PlainSocketOutputStream.write(PlainSocketImpl.java:272) at com.android.okio.Okio$1.write(Okio.java:70) at com.android.okio.RealBufferedSink.emitCompleteSegments(RealBufferedSink.java:116) at com.android.okio.RealBufferedSink.write(RealBufferedSink.java:44) at com.android.okhttp.internal.http.HttpConnection$ChunkedSink.write(HttpConnection.java:334) at com.android.okio.RealBufferedSink.emitCompleteSegments(RealBufferedSink.java:116) at com.android.okio.RealBufferedSink$1.write(RealBufferedSink.java:131) at com.mayan.ameritrade.android.tools.Server$override.addFilePart(Server.java:435) at com.mayan.ameritrade.android.tools.Server$override.access$dispatch(Server.java) at com.mayan.ameritrade.android.tools.Server.addFilePart(Server.java:0) at java.lang.reflect.Method.invoke(Native Method) at java.lang.reflect.Method.invoke(Method.java:372) at com.android.tools.fd.runtime.AndroidInstantRuntime.invokeProtectedStaticMethod(AndroidInstantRuntime.java:170) at com.mayan.ameritrade.android.tools.Server$override.setPicture(Server.java:363) at com.mayan.ameritrade.android.tools.Server$override.access$dispatch(Server.java) at com.mayan.ameritrade.android.tools.Server.setPicture(Server.java:0) at com.mayan.ameritrade.android.MainActivity$2$1.run(MainActivity.java:99) at java.lang.Thread.run(Thread.java:818) Caused by: android.system.ErrnoException: sendto failed: EPIPE (Broken pipe) at libcore.io.Posix.sendtoBytes(Native Method) at libcore.io.Posix.sendto(Posix.java:206) at libcore.io.BlockGuardOs.sendto(BlockGuardOs.java:278) at libcore.io.IoBridge.sendto(IoBridge.java:553) ... 20 more

我现在不知道该怎么办，感谢您的帮助!

Answer 1

您不能使用 PrintWriter 上传图像...您不会...但是...

PrintWriter 仅用于文本。

您正在混合使用 PrintWriter 和普通的 OutputStream。那不行。

您应该只写入一种类型的流。