HTTPURLConnection 缓冲区错误

Question

我正在尝试上传照片并将 JSON 字符串传递给服务器。

我的猜测是我错误地计算了内容长度。但我不确定我的数学问题出在哪里。

谁能帮我找出我的错误？

我收到以下错误：

E/PhotoUpload：错误：预期 14591 字节，但收到 15183 java.net.ProtocolException：预期 14591 字节，但收到 15183 com.android.okhttp.internal.http.HttpConnection$FixedLengthSink.write(HttpConnection.java:311) 在 com.android.okio.RealBufferedSink.flush(RealBufferedSink.java:154) 在 com.android.okio.RealBufferedSink$1.flush(RealBufferedSink.java:137) 在 java.io.FilterOutputStream.flush(FilterOutputStream.java:88) 在 java.io.DataOutputStream.flush(DataOutputStream.java:63) 在 com.mycompany.myapp.TakePhotoActivity$BGUploadImage.doInBackground(TakePhotoActivity.java:381) 在 com.mycompany.myapp.TakePhotoActivity$BGUploadImage.doInBackground(TakePhotoActivity.java:273)

E/PhotoUpload：错误：预期 14591 字节，但收到 15183 java.net.ProtocolException：预期 14591 字节，但收到 15183 com.android.okhttp.internal.http.HttpConnection$FixedLengthSink.write(HttpConnection.java:311) 在 com.android.okio.RealBufferedSink.flush(RealBufferedSink.java:154) 在 com.android.okhttp.internal.http.HttpEngine.readResponse(HttpEngine.java:769) 在 com.android.okhttp.internal.http.HttpURLConnectionImpl.execute(HttpURLConnectionImpl.java:405) 在 com.android.okhttp.internal.http.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:349) 在 com.android.okhttp.internal.http.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:203) 在 com.android.okhttp.internal.http.DelegatingHttpsURLConnection.getInputStream(DelegatingHttpsURLConnection.java:210) 在 com.android.okhttp.internal.http.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:25) 在 com.mycompany.myapp.TakePhotoActivity$BGUploadImage.doInBackground(TakePhotoActivity.java:393) 在 com.mycompany.myapp.TakePhotoActivity$BGUploadImage.doInBackground(TakePhotoActivity.java:273) 在 android.os.AsyncTask$2.call(AsyncTask.java:292)

 public class BGUploadImage extends AsyncTask<String, Integer, Integer> {
        int maxBufferSize = 1 * 256 * 1024;
        int headerSize = 89;
        String urlString = "http://www.mywebsite.com/someapi";
        int fileSize = 0;
        int infoSize = 0;
        private int i;


        @Override
        protected void onPreExecute() {
        }

        @Override
        protected void onProgressUpdate(Integer... values) {
        }

        @Override
        protected Integer doInBackground(String... file) {

            Integer ret = 0;

            HttpURLConnection conn = null;
            DataOutputStream dos = null;
            DataInputStream inStream = null;

            String exsistingFileName = file[0];

            String lineEnd = "\r\n";
            String twoHyphens = "--";
            String boundary = "---------------------------14737809831466499882746641449";

            String json = JSONCalls.uploadImageJSON(thisCallKey);

            int bytesRead, bytesAvailable, bufferSize;
            byte[] buffer;

            try {
                Log.i("PhotoUpload", "Start uploading file: " + file[0]);

                FileInputStream fileInputStream = new FileInputStream(new File(exsistingFileName));

                URL url = new URL(urlString);

                conn = (HttpURLConnection) url.openConnection();
                conn.setDoInput(true);
                conn.setDoOutput(true);
                conn.setUseCaches(false);

                fileSize = fileInputStream.available();
                infoSize = fileSize + headerSize + file[0].length();
                conn.setFixedLengthStreamingMode(infoSize);
                conn.setRequestMethod("POST");
                conn.setRequestProperty("Connection", "Keep-Alive");
                conn.setRequestProperty("Content-Type", "multipart/form-data;boundary=" + boundary);

                dos = new DataOutputStream(conn.getOutputStream());

                //JSON PART
                dos.writeBytes(twoHyphens + boundary + lineEnd);
                dos.writeBytes("Content-Disposition: form-data; name='params'" + lineEnd);
                dos.writeBytes(json);
                dos.writeBytes(lineEnd);

                //MEDIA PART
                dos.writeBytes(twoHyphens + boundary + lineEnd);
                dos.writeBytes("Content-Disposition: form-data;  name = 'UploadedFile'; filename = '" + file[0] + "' " + lineEnd);
                dos.writeBytes(lineEnd);

                // create a buffer of maximum size
                bytesAvailable = fileInputStream.available();
                bufferSize = Math.min(bytesAvailable, maxBufferSize);
                buffer = new byte[bufferSize];

                // read file and write it into form...
                bytesRead = fileInputStream.read(buffer, 0, bufferSize);

                int bytesSent = 0;
                while (bytesRead > 0) {
                    if (bytesSent > 0) {
                        int pg = (bytesSent * 100) / infoSize;
                        publishProgress(pg);
                    }
                    bytesSent += bufferSize;
                    dos.write(buffer, 0, bufferSize);
                    bytesAvailable = fileInputStream.available();
                    bufferSize = Math.min(bytesAvailable, maxBufferSize);
                    bytesRead = fileInputStream.read(buffer, 0, bufferSize);
                }

                // send multipart form data necesssary after file data...
                dos.writeBytes(lineEnd);
                dos.writeBytes(twoHyphens + boundary + twoHyphens + lineEnd);

                //close streams
                fileInputStream.close();
                dos.flush();
                dos.close();

            } catch (MalformedURLException ex) {
                Log.e("PhotoUpload", "error: " + ex.getMessage(), ex);
                ret = 1;
            } catch (IOException ioe) {
                Log.e("PhotoUpload", "error: " + ioe.getMessage(), ioe);
                ret = 1;
            }

            try {
                inStream = new DataInputStream(conn.getInputStream());
                String str;

                while ((str = inStream.readLine()) != null) {
                    Log.i("PhotoUpload", "Server Response" + str);
                }
                inStream.close();
            } catch (IOException ioex) {
                Log.e("PhotoUpload", "error: " + ioex.getMessage(), ioex);
                ret = 1;
            }

            return ret;
        }

        @Override
        protected void onPostExecute(Integer r) {

        }

    }
}

Answer 1

我的猜测是我错误地计算了内容长度。

由于您根本没有计算或发送内容长度，因此很难理解这种猜测可能基于什么。

但是，您的代码还存在其他问题。你的复制循环：

// read file and write it into form...
bytesRead = fileInputStream.read(buffer, 0, bufferSize);
int bytesSent = 0;
while (bytesRead > 0) {
    if (bytesSent > 0) {
        int pg = (bytesSent * 100) / infoSize;
        publishProgress(pg);
    }
    bytesSent += bufferSize;
    dos.write(buffer, 0, bufferSize);
    bytesAvailable = fileInputStream.available();
    bufferSize = Math.min(bytesAvailable, maxBufferSize);
    bytesRead = fileInputStream.read(buffer, 0, bufferSize);
}

真是一团糟。 Java 复制循环并不比这更复杂：

byte[] buffer = new byte[8192];
int count;
while ((count = in.read(buffer)) > 0)
{
    out,write(buffer, 0, count);
}

您不需要与文件大小相同的缓冲区。这只是浪费空间。在 Javadoc 中特别警告不要使用available() 作为文件大小的度量，或者为其分配足够大的缓冲区。那不是它的目的。 available() 的正确用法很少，这不是其中之一。

close() 之前的flush() 是多余的。