java后台调用接口并返回值

import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
public class HttpOrderUtil {
	// 接口
	private static final String post_url = "接口的地址";

	public static String httpURLConnectionPOST(需要传的参数) {
		StringBuilder sb = new StringBuilder();
		try {
			URL url = new URL(post_url);//把字符串转换为URL请求地址
			HttpURLConnection connection = (HttpURLConnection) url
					.openConnection();//此时cnnection只是为一个连接对象,待连接中 
			connection.setConnectTimeout(5 * 1000);//设置连接超时时间为5秒  
			connection.setReadTimeout(20 * 1000);//设置读取超时时间为20秒   
			connection.setDoOutput(true);//设置连接输出流为true,默认false
			connection.setDoInput(true);//设置连接输入流为true  
			connection.setRequestMethod("POST");//设置请求方式为post 
			connection.setUseCaches(false);// post请求缓存设为false  
			connection.setInstanceFollowRedirects(true);//设置该HttpURLConnection实例是否自动执行重定向 
			connection.setRequestProperty("Content-Type",
					"application/x-www-form-urlencoded;charset=utf-8");//请求的content-type为application/x-www-form-urlencoded;
																		//charset=UTF-8
			connection.connect();//建立连接
			DataOutputStream dataout = new DataOutputStream(
					connection.getOutputStream());//创建输入输出流,用于往连接里面输出携带的参数
			String 参数= "参数="
					+ URLEncoder.encode(需要传的参数, "utf-8");
			dataout.writeBytes(参数);
			dataout.flush();//输出完成后刷新并关闭流  
			dataout.close();
			//System.out.println(connection.getResponseCode());
			// 如果请求响应码是200，则表示成功 
			if (connection.getResponseCode() == 200) {
				BufferedReader bf = new BufferedReader(new InputStreamReader(
						connection.getInputStream(), "UTF-8"));
				String line;
				while ((line = bf.readLine()) != null) {
					sb.append(line);
				}
				bf.close();
			}
			connection.disconnect();//断开连接
		} catch (IOException e) {
			e.printStackTrace();
		}
		return sb.toString();
	}

}