Posting a large file in Android

问题

I sometimes get an OutOfMemoryError when posting a large file in Android. This is the code I'm using. Am I doing something wrong?

HttpURLConnection con = (HttpURLConnection) url.openConnection();
con.setRequestMethod("POST");
con.setDoInput(true);
con.setDoOutput(true);
ostream = new DataOutputStream(con.getOutputStream());
byte[] buffer = new byte[1536];
int count;
while ((count = fileInput.read(buffer)) != -1) {
    ostream.write(buffer, 0, count); // This sometimes causes OutOfMemoryError
}
ostream.flush();

Would calling ostream.flush() inside the while loop do any good?

回答1:

If you do it like that, the whole POST must be buffered in memory. This is because it needs to send the Content-Length header first.

Instead, I think you want to use the Apache HTTP libraries, including FileEntity. That will let it figure out the length before reading the file. You can use this answer as a starting point. But the second parameter to the FileEntity constructor should be a mime type (like image/png, text/html, etc.).

回答2:

HTTP connection is fine, but HTTPS will trigger Out of Memory error because there is a bug in HttpsURLConnectionImpl.java in Android 2.3.4 (verified on my tablet), and it's fixed in Android 4.1 (I have checked the source code).

By the way, he should avoid buffering the whole POST data in RAM by adding "con.setChunkedStreamingMode(0);" immediately after "con.setDoOutput(true);" statement.

来源：https://stackoverflow.com/questions/4455006/posting-a-large-file-in-android