0

我在使用此功能时遇到问题。我得到了长度（）；我需要上传的文件，我得到下一个错误->

总是比预期更多的字节

Exception : expected 589715 bytes but received 589840
java.io.IOException: expected 589715 bytes but received 589840
at libcore.net.http.FixedLengthOutputStream.write(FixedLengthOutputStream.java:39)
at java.io.DataOutputStream.write(DataOutputStream.java:98)
at com.androidexample.uploadtoserver.UploadToServer.uploadFile(UploadToServer.java:152)
at com.androidexample.uploadtoserver.UploadToServer$1.run(UploadToServer.java:62)
at java.lang.Thread.run(Thread.java:856)

我用它来获取文件的大小

int fixedLength = (int) fileInputStream.getChannel().size();
int total = (int) sourceFile.length();

是否可以正确发布工作 setFixedLengthStreamingMode(int) 的示例？我只能看到这种方法的问题

完整的代码在这里，是的，它用于传输一个文件或一些文件，每个文件可能很少或超过 15 Mb，有时我会在一些旧设备中出现内存不足。

public int uploadFile(String sourceFileUri) {

    String fileName = sourceFileUri;

    HttpURLConnection conn = null;
    DataOutputStream dos = null;  
    String lineEnd = "\r\n";
    String twoHyphens = "--";
    String boundary = "*****";
    int bytesRead, bytesAvailable, bufferSize;
    byte[] buffer;
    int maxBufferSize = 1 * 1024 * 1024; 
    File sourceFile = new File(sourceFileUri); 

    if (!sourceFile.isFile()) {
        runOnUiThread(new Runnable() {
            public void run() {
                /*   messageText.setText("Source File not exist :"
                        +uploadFilePath + "" + uploadFileName);*/
            }
        }); 

        return 0;
    } else {
        try { 
            FileInputStream fileInputStream = new FileInputStream(sourceFile);
            int fixedLength = (int) fileInputStream.getChannel().size();
            URL url = new URL(upLoadServerUri);
            //int total = (int) sourceFile.length();
            // Open a HTTP  connection to  the URL
            conn = (HttpURLConnection) url.openConnection();
            conn.setFixedLengthStreamingMode(fixedLength);
            conn.setDoInput(true); // Allow Inputs
            conn.setDoOutput(true); // Allow Outputs
            conn.setUseCaches(false); // Don't use a Cached Copy
            conn.setRequestMethod("POST");
            conn.setRequestProperty("Connection", "Keep-Alive");
            conn.setRequestProperty("ENCTYPE", "multipart/form-data");
            conn.setRequestProperty("Content-Type", "multipart/form-data;boundary=" + boundary);
            conn.setRequestProperty("uploaded_file", fileName); 
            conn.setRequestProperty("mail", MAIL); 
            conn.setRequestProperty("OS", "1");
            conn.setRequestProperty("LANG", "ES");
            //conn.setChunkedStreamingMode(maxBufferSize);

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

            dos.writeBytes(twoHyphens + boundary + lineEnd); 
            dos.writeBytes("Content-Disposition: form-data; name=\"uploaded_file\";filename=\""
                    + fileName + "\"" + 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);  

            while (bytesRead > 0) {
                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);

            // Responses from the server (code and message)
            serverResponseCode = conn.getResponseCode();
            // String serverResponseMessage = conn.getResponseMessage();

            // Log.i("uploadFile", "HTTP Response is : " 
            //       + serverResponseMessage + ": " + serverResponseCode);

            if(serverResponseCode == 200) {
                runOnUiThread(new Runnable() {
                    public void run() {
                        /*messageText.setText(msg);
                        Toast.makeText(UploadToServer.this, "File Upload Complete.", 
                                     Toast.LENGTH_SHORT).show();*/
                    }
                });
            }    

            //close the streams //
            fileInputStream.close();
            dos.flush();
            dos.close();
        }
    }
}
4

1 回答 1

3

您必须将其设置为要传输的总字节数。显然，您发送的不止于此。您尚未显示相关代码，因此无法进一步评论。

为什么是 DataOutputStream？你不需要它只是为了发送一个文件。

编辑：您的代码存在许多问题。

dos.writeBytes(twoHyphens + boundary + lineEnd); 
dos.writeBytes("Content-Disposition: form-data; name=\"uploaded_file\";filename=\""
                                     + fileName + "\"" + lineEnd);
dos.writeBytes(lineEnd);

这就是破坏固定长度传输模式的原因。你还没有把这些东西算作固定长度的一部分。

// create a buffer of  maximum size

您不需要最大大小的缓冲区。8192 字节的缓冲区就足够了。

bytesAvailable = fileInputStream.available();

InputStream.available()在 Javadoc中具体描述如下：“使用此方法的返回值来分配旨在保存此流中所有数据的缓冲区是不正确的。” 幸运的是，您可以删除这一行。

bufferSize = Math.min(bytesAvailable, maxBufferSize);
buffer = new byte[bufferSize];

没必要，见上。只需使用new byte[8192].

// read file and write it into form...
bytesRead = fileInputStream.read(buffer, 0, bufferSize);  
while (bytesRead > 0) {
    dos.write(buffer, 0, bufferSize);
    bytesAvailable = fileInputStream.available();
    bufferSize = Math.min(bytesAvailable, maxBufferSize);
    bytesRead = fileInputStream.read(buffer, 0, bufferSize);   
}

这又是错误的。这是一个滥用的available()开始。在 Java 中复制流的标准方法如下：

while ((count = in.read(buffer)) > 0)
{
    out.write(buffer, 0, count);
}

它适用于任何大于零的缓冲区大小；它不关心输入有多长；并且无论大小如何，它都可以正确地用于最终读取。

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

同样，您还没有将其计为固定长度传输大小的一部分。

但是我必须说你最好使用分块传输模式并让HttpURLConnection所有繁重的工作完成：你所需要的只是上面的复制循环。

于 2013-10-29T22:18:57.103 回答