写一段java代码 发送post请求

import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;public class HttpPostRequest { private final String USER_AGENT = "Mozilla/5.0"; public static void main(String[] args) throws Exception { HttpPostRequest http = new HttpPostRequest(); System.out.println("\nTesting 2 - Send Http POST request");
http.sendPost(); } // HTTP POST request
private void sendPost() throws Exception { String url = "http://www.example.com/post";
URL obj = new URL(url);
HttpURLConnection con = (HttpURLConnection) obj.openConnection(); //add reuqest header
con.setRequestMethod("POST");
con.setRequestProperty("User-Agent", USER_AGENT);
con.setRequestProperty("Accept-Language", "en-US,en;q=0.5"); String urlParameters = "sn=C02G8416DRJM&cn=&locale=&caller=&num=12345"; // Send post request
con.setDoOutput(true);
DataOutputStream wr = new DataOutputStream(con.getOutputStream());
wr.writeBytes(urlParameters);
wr.flush();
wr.close(); int responseCode = con.getResponseCode();
System.out.println("\nSending 'POST' request to URL : " + url);
System.out.println("Post parameters : " + urlParameters);
System.out.println("Response Code : " + responseCode); BufferedReader in = new BufferedReader(
new InputStreamReader(con.getInputStream()));
String inputLine;
StringBuffer response = new StringBuffer(); while ((inputLine = in.readLine()) != null) {
response.append(inputLine);
}
in.close(); //print result
System.out.println(response.toString()); }}