java发送Http Post调用接口

public String sendPost_body(String arl, String s) {

// 创建url资源
OutputStreamWriter out = null;
URL url;
BufferedReader in = null;
StringBuilder result = new StringBuilder();
try {
url = new URL(arl);

// 建立http连接
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
// 设置允许输出
conn.setDoOutput(true);
conn.setDoInput(true);
// 设置不用缓存
conn.setUseCaches(false);
// 设置传递方式
conn.setDoOutput(true);
conn.setDoInput(true);
conn.setUseCaches(false);
conn.setInstanceFollowRedirects(true);
conn.setRequestMethod("POST"); // 设置请求方式
conn.setRequestProperty("Accept", "application/json"); // 设置接收数据的格式
conn.setRequestProperty("Content-Type", "application/json"); // 设置发送数据的
conn.setRequestProperty("user-agent",
"Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");//设置消息头，解决508错误
// 开始连接请求
conn.connect();
out = new OutputStreamWriter(
conn.getOutputStream(), "UTF-8"); // utf-8编码
// 写入请求的字符串
out.append(s);
out.flush();
out.close();
// System.out.println(conn.getResponseCode());
if(conn.getResponseCode()==200){
// System.out.println("success");
in = new BufferedReader(new InputStreamReader(conn.getInputStream(),"utf-8"));
String line;
while ((line = in.readLine()) != null) {
result.append(line);
}
}

} catch (Exception e) {
// System.out.println("发送 POST 请求出现异常！" + e);
result = new StringBuilder("{\"resCode\":\"1\",\"errCode\":\"1001\",\"resData\":\"\"}");
e.printStackTrace();
// log.error("远程服务未开启", e);
}
finally {
try {
if (out != null) {
out.close();
}
if (in != null) {
in.close();
}
} catch (IOException ex) {
ex.printStackTrace();
}
}
return result.toString();

}