这段代码用于从android手机向服务器上传图片文件，非FTP方式，当然稍作修改就可以用于上传其它文件。各位看官可以根据自己需要进行适当修改。不足之处还请指出，谢谢！
/**
* upload file by making a form and return whether file upload successfuly
*
* @author Chen.Zhidong
* @param params
* @param dirname
* @param filename
* @param link
* @return boolean whether file upload succeeded or failed
*/
public static boolean fileUpload(Map<string , String> params, String dirname, String filename, String link) {
try {
String BOUNDARY = "---";
String MULTIPART_FORM_DATA = "Multipart/form-data";
URL url = new URL(link);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setDoInput(true);
conn.setDoOutput(true);
conn.setUseCaches(false);
conn.setRequestMethod("POST");
conn.setRequestProperty("Connection", "Keep-Alive");
conn.setRequestProperty("Charset", "UTF-8");
conn.setRequestProperty("Content-Type", MULTIPART_FORM_DATA + ";boundary=" + BOUNDARY);
DataOutputStream outStream = new DataOutputStream(conn.getOutputStream());
if (params != null && !params.isEmpty()) {
StringBuilder sb = new StringBuilder();
for (Map.Entry</string><string , String> entry : params.entrySet()) {
sb.append(BOUNDARY);
sb.append("\r\n");
sb.append("Content-Disposition: form-data; name=\"" + entry.getKey() + "\"\r\n\r\n");
sb.append(entry.getValue());
sb.append("\r\n");
}
outStream.write(sb.toString().getBytes());
}
//此处用的是我自己写的一个读图片的函数，看官可以改成自己的获取文件到byte[]的函数
byte[] content = ImageUtil.readImageByte(dirname + '/' + filename);
StringBuilder split = new StringBuilder();
split.append(BOUNDARY);
split.append("\r\n");
split.append("Content-Disposition: form-data;name=\"imgfile\";filename=\"" + filename + "\"\r\n");
split.append("Content-Type: image/jpg\r\n");
outStream.write(split.toString().getBytes());
outStream.write(content, 0, content.length);
outStream.write("\r\n".getBytes());
byte[] end_data = (BOUNDARY + "--\r\n").getBytes();
outStream.write(end_data);
outStream.flush();
if (conn.getInputStream() != null) {
conn.disconnect();
return true;
}
else {
conn.disconnect();
}
}catch (IOException e) {
e.printStackTrace();
}
return false;
}