本文介绍了上传邮寄文件服务器内存不足的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我正在开发一个远程备份应用程序，有时候我需要上传大文件，例如15 MB，我已经在一些手机进行测试，我得到一个内存不足的错误
I'm developing a remote backup app, and Sometimes I need upload big files as for example 15 MB, I have tested in some phones I get an out of memory error
有没有办法使用这个功能来使用较少的内存？
Is there a way to use less memory using this function?
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 {
// open a URL connection to the Servlet
FileInputStream fileInputStream = new FileInputStream(sourceFile);
URL url = new URL(upLoadServerUri);
// Open a HTTP connection to the URL
conn = (HttpURLConnection) url.openConnection();
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);
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();
} catch (MalformedURLException ex) {
// ex.printStackTrace();
runOnUiThread(new Runnable() {
public void run() {
/*messageText.setText("MalformedURLException Exception : check script url.");*/
Toast.makeText(UploadToServer.this, "MalformedURLException", Toast.LENGTH_SHORT).show();
}
});
Log.e("Upload file to server", "error: " + ex.getMessage(), ex);
} catch (Exception e) {
//e.printStackTrace();
runOnUiThread(new Runnable() {
public void run() {
//messageText.setText("Got Exception : see logcat ");
Toast.makeText(UploadToServer.this, "Got Exception : see logcat ",
Toast.LENGTH_SHORT).show();
}
});
Log.e("Upload file to server Exception", "Exception : "
+ e.getMessage(), e);
}
// dialog.dismiss();
return serverResponseCode;
} // End else block
}
下面的错误日志
java.lang.OutOfMemoryError
at java.io.ByteArrayOutputStream.expand(ByteArrayOutputStream.java:93)
at java.io.ByteArrayOutputStream.write(ByteArrayOutputStream.java:218)
at org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl$DefaultHttpOutputStream.write(HttpURLConnectionImpl.java:750)
at java.io.DataOutputStream.write(DataOutputStream.java:101)
at com.androidexample.uploadtoserver.UploadToServer.a(SourceFile:151)
at com.androidexample.uploadtoserver.e.run(SourceFile:62)
at java.lang.Thread.run(Thread.java:1102)
在修改和添加固定没有缓冲区我得到这个错误
After modify and add Fixed no Buffer i get this error
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)
我想这字节的区别是标题的数据吗？我怎么能得到头的长度（）？
I guess this bytes of difference are the headers data right? how can I get the length() of the headers?
推荐答案
您应该使用的 setChunkedStreamingMode（）或 setFixedLengthStreamingMode（）的HttpURLConnection的方法。这将prevent你的数据在内存中排出，使其缓冲。
You should use either the setChunkedStreamingMode() or setFixedLengthStreamingMode() methods of the HttpURLConnection. This will prevent the buffering of your data in memory and exhausting it.
从文档相关报价：
为了获得最佳性能，你应该叫任 setFixedLengthStreamingMode（INT）当主体长度是已知的在 提前，或setChunkedStreamingMode（INT），当它不是。除此以外 的HttpURLConnection将被迫缓冲完整请求体 在存储器之前被发送，浪费（也可能是辛苦的） 堆和增加延迟。
这里更多： http://developer.android.com/reference/java /net/HttpURLConnection.html
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