我正在开发一个可以将不同文件发送到 Web 服务器的应用程序。我还想发送大文件，为了做到这一点，我需要对文件进行分块。但是当我将文件发送到服务器时，什么都没有上传。我不知道我发送文件的方式是否有错误，它在我的响应中给出错误 500（内部服务器错误）。我认为服务器不是问题，因为当我使用上传文件时multiPartEntity 它可以工作，但是当我使用 BufferedInputStream 和 DataOutputStream 时它不起作用。请帮助我并告诉我的代码有什么问题，为什么它不能发送我的文件。这是我到目前为止：
String samplefile = "storage/sdcard0/Pictures/Images/picture.jpg";
File mFile = new File(samplefile);
int mychunkSize = 2048 * 1024;
final long size = mFile.length();
final long chunks = size < mychunkSize? 1: (mFile.length() / mychunkSize);
int chunkId = 0;
try {
BufferedInputStream stream = new BufferedInputStream(new FileInputStream(mFile));
String lineEnd = "\r\n";
String twoHyphens = "--";
String boundary = "-------------------------acebdf13572468";// random data
for (chunkId = 0; chunkId < chunks; chunkId++) {
URL url = new URL(urlString);
// Open a HTTP connection to the URL
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setReadTimeout(20000 /* milliseconds */);
conn.setConnectTimeout(20000 /* milliseconds */);
// Allow Inputs
conn.setDoInput(true);
// Allow Outputs
conn.setDoOutput(true);
// Don't use a cached copy.
conn.setUseCaches(false);
// Use a post method.
conn.setRequestMethod("POST");
String encoded = Base64.encodeToString((_username+":"+_password).getBytes(),Base64.NO_WRAP);
conn.setRequestProperty("Authorization", "Basic "+encoded);
conn.setRequestProperty("Connection", "Keep-Alive");
conn.setRequestProperty("Content-Type", "multipart/form-data;boundary="+boundary);
DataOutputStream dos = new DataOutputStream( conn.getOutputStream() );
dos.writeBytes(twoHyphens + boundary + lineEnd);
String param1 = ""+chunkId;
String param2 = ""+chunks;
String param3 = mFile.getName();
String param4 = samplefile;
// Send parameter #file
dos.writeBytes("Content-Disposition: form-data; name=\"fieldNameHere\";filename=\"" + param3 + "\"" + lineEnd); // filename is the Name of the File to be uploaded
dos.writeBytes("Content-Type: image/jpeg" + lineEnd);
dos.writeBytes(lineEnd);
// Send parameter #chunks
dos.writeBytes("Content-Disposition: form-data; name=\"chunk\"" + lineEnd);
dos.writeBytes("Content-Type: text/plain; charset=UTF-8" + lineEnd);
dos.writeBytes("Content-Length: " + param2.length() + lineEnd);
dos.writeBytes(lineEnd);
dos.writeBytes(param2 + lineEnd);
dos.writeBytes(twoHyphens + boundary + lineEnd);
// Send parameter #name
dos.writeBytes("Content-Disposition: form-data; name=\"name\"" + lineEnd);
dos.writeBytes("Content-Type: text/plain; charset=UTF-8" + lineEnd);
dos.writeBytes("Content-Length: " + param3.length() + lineEnd);
dos.writeBytes(lineEnd);
dos.writeBytes(param3 + lineEnd);
dos.writeBytes(twoHyphens + boundary + lineEnd);
byte[] buffer = new byte[mychunkSize];
stream.read(buffer);
dos.write(buffer);
dos.writeBytes(lineEnd);
dos.writeBytes(twoHyphens + boundary + twoHyphens + lineEnd);
dos.flush();
dos.close();
}
} catch (Exception e) {
Log.e("Error Uploading Files", e.toString());
}