android 使用post方式上传文件

public static String post(String actionUrl, Map<String, String> params,

Map<String, File> files) throws IOException {

String BOUNDARY = java.util.UUID.randomUUID().toString();

String PREFIX = "--", LINEND = "\r\n";

String MULTIPART_FROM_DATA = "multipart/form-data";

String CHARSET = "UTF-8";

URL uri = new URL(actionUrl);

HttpURLConnection conn = (HttpURLConnection) uri.openConnection();

conn.setReadTimeout(5 * 1000);

conn.setDoInput(true);// 允许输入

conn.setDoOutput(true);// 允许输出

conn.setUseCaches(false);

conn.setRequestMethod("POST"); // Post方式

conn.setRequestProperty("connection", "keep-alive");

conn.setRequestProperty("Charsert", "UTF-8");

conn.setRequestProperty("Content-Type", MULTIPART_FROM_DATA

+ ";boundary=" + BOUNDARY);

// 首先组拼文本类型的参数

StringBuilder sb = new StringBuilder();

for (Map.Entry<String, String> entry : params.entrySet()) {

sb.append(PREFIX);

sb.append(BOUNDARY);

sb.append(LINEND);

sb.append("Content-Disposition: form-data; name=\""

+ entry.getKey() + "\"" + LINEND);

sb.append("Content-Type: text/plain; charset=" + CHARSET + LINEND);

sb.append("Content-Transfer-Encoding: 8bit" + LINEND);

sb.append(LINEND);

sb.append(entry.getValue());

sb.append(LINEND);

}

DataOutputStream outStream = new DataOutputStream(conn

.getOutputStream());

outStream.write(sb.toString().getBytes());

// 发送文件数据

if (files != null)

for (Map.Entry<String, File> file : files.entrySet()) {

StringBuilder sb1 = new StringBuilder();

sb1.append(PREFIX);

sb1.append(BOUNDARY);

sb1.append(LINEND);

sb1

.append("Content-Disposition: form-data; name=\"file\"; filename=\""

+ file.getKey() + "\"" + LINEND);

sb1.append("Content-Type: application/octet-stream; charset="

+ CHARSET + LINEND);

sb1.append(LINEND);

outStream.write(sb1.toString().getBytes());

InputStream is = new FileInputStream(file.getValue());

byte[] buffer = new byte[1024];

int len = 0;

while ((len = is.read(buffer)) != -1) {

outStream.write(buffer, 0, len);

}

is.close();

outStream.write(LINEND.getBytes());

}

// 请求结束标志

byte[] end_data = (PREFIX + BOUNDARY + PREFIX + LINEND).getBytes();

outStream.write(end_data);

outStream.flush();

// 得到响应码

int res = conn.getResponseCode();

InputStream in = conn.getInputStream();

InputStreamReader isReader = new InputStreamReader(in);

BufferedReader bufReader = new BufferedReader(isReader);

String line = null;

String data = "OK";

while ((line = bufReader.readLine()) == null)

data += line;

if (res == 200) {

int ch;

StringBuilder sb2 = new StringBuilder();

while ((ch = in.read()) != -1) {

sb2.append((char) ch);

}

}

outStream.close();

conn.disconnect();

return in.toString();

}