android 文件io流的上传

public static String post(Map<String, String> params,
Map<String, File> files) throws IOException {
String result = null;
String BOUNDARY = java.util.UUID.randomUUID().toString();
String PREFIX = "--", LINEND = "\r\n";
String MULTIPART_FROM_DATA = "multipart/form-data";
String CHARSET = "UTF-8";
URL url = new URL(Constants.WEB_URL);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setConnectTimeout(8 * 1000);
conn.setReadTimeout(8 * 1000); // 缓存的最长时间
conn.setDoInput(true);// 允许输入
conn.setDoOutput(true);// 允许输出
conn.setUseCaches(false); // 不允许使用缓存
conn.setRequestMethod("POST");
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());

InputStream in = null;
// 发送文件数据
if (files != null && !files.isEmpty()) {
// int i = 0;
for (Map.Entry<String, File> file : files.entrySet()) {
StringBuilder sb1 = new StringBuilder();
sb1.append(PREFIX);
sb1.append(BOUNDARY);
sb1.append(LINEND);
String name = file.getKey().substring(0,
file.getKey().lastIndexOf("."));
sb1.append("Content-Disposition: form-data; name=\"" + name
+ "\"; filename=\"" + file.getKey() + "\"" + LINEND);//name是文件的格式，filename是文件名字
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());
// i++;
}
// 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();
if (conn.getResponseCode() == 200) {
in = conn.getInputStream();
int ch;
StringBuilder sb2 = new StringBuilder();
while ((ch = in.read()) != -1) {
sb2.append((char) ch);
}
LogToos.LogDebug(sb2.toString());
result = sb2.toString();
} else {
result = null;
}
outStream.close();
conn.disconnect();
}
return result;
}