java调用http接口并解析返回的json对象（URLConnection、HttpURLConnection、HttpClien）三种方式

URLConnection方式：

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.URL;
import java.net.URLConnection;
import java.net.URLEncoder;
import java.util.HashMap;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;

import net.sf.json.JSONObject;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;

public class Test {

    //调用http接口
    @RequestMapping(value="testInterfaces.htm", method={RequestMethod.GET, RequestMethod.POST})
    public void testInterfaces(HttpServletRequest request) throws Exception{
        //传入中文参数并设置编码格式
        String param = "{\"url\":\"中文\"}";
        param = URLEncoder.encode(param, "UTF-8");
            Print