java http请求工具类

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.URL;
import java.net.URLConnection;
import java.util.List;
import java.util.Map;

public class HttpRequestUtils {

    
     /**
    * @Title sendGet
    * @Description 向指定URL发送GET方法的请求
    * @param url 发送请求的URL
    * @param param 请求参数，请求参数应该是 name1=value1&name2=value2 的形式。
    * @Return String 返回类型
    * @Throws
    */
    public static String sendGet(String url, String param) {
            String result = "";
            BufferedReader in = null;
            try {
                String urlNameString = url + "?" + param;
                URL realUrl = new URL(urlNameString);
                // 打开和URL之间的连接
                URLConnection connection = realUrl.openConnection();
                // 设置通用的请求属性
                connection.setRequestProperty("accept", "*/*");
                connection.setRequestProperty("connection", "Keep-Alive");
                connection.setRequestProperty("user-agent",
                        "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
                // 建立实际的连接
                connection.connect();
                // 获取所有响应头字段
                Map<String, List<String>> map = connection.getHeaderFields();
                // 遍历所有的响应头字段
                for (String key : map.keySet()) {
                    System.out.println(key + "--->" + map.get(key));
                }
                // 定义 BufferedReader输入流来读取URL的响应
                in = new BufferedReader(new InputStreamReader(
                        connection.getInputStream()));
                String line;
                while ((line = in.readLine()) != null) {
                    result += line;
                }
            } catch (Exception e) {
               System.out.println("发送GET请求出现异常！" + e);
                e.printStackTrace();
            }
            // 使用finally块来关闭输入流
            finally {
                try {
                    if (in != null) {
                        in.close();
                    }
                } catch (Exception e2) {
                    e2.printStackTrace();
                }
            }
            return result;
    }
    
    /**
    * @Title sendPost
    * @Description  向指定 URL 发送POST方法的请求
    * @param url 发送请求的URL
    * @param param 请求参数应该是 name1=value1&name2=value2 的形式
    * @return
    * @Return String 返回类型
    * @Throws
    */
    public static String sendPost(String url, String param) {
        PrintWriter out = null;
        BufferedReader in = null;
        String result = "";
        try{
            URL realUrl = new URL(url);
            // 打开和URL之间的连接
            URLConnection conn = realUrl.openConnection();
            // 设置通用的请求属性
            conn.setRequestProperty("accept", "*/*");
            conn.setRequestProperty("connection", "Keep-Alive");
            conn.setRequestProperty("user-agent",
                    "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
            //发送POST请求必须设置如下两行
            conn.setDoOutput(true);
            conn.setDoInput(true);
            // 获取URLConnection对象对应的输出流
            out = new PrintWriter(conn.getOutputStream());
            // 发送请求参数
            out.print(param);
            // flush输出流的缓冲
            out.flush();
            // 定义BufferedReader输入流来读取URL的响应
            in = new BufferedReader(
                    new InputStreamReader(conn.getInputStream()));
            String line;
            while ((line = in.readLine()) != null) {
                result += line;
            }
        }catch (Exception e) {
           System.out.println("发送 POST 请求出现异常！"+e);
           e.printStackTrace();
        }
        //使用finally块来关闭输出流、输入流
        finally{
            try{
                if(out!=null){
                    out.close();
                }
                if(in!=null){
                    in.close();
                }
            }
            catch(IOException ex){
                ex.printStackTrace();
            }
        }
        return result;
    }
    
    public static void main(String[] args) {
        //String tokenUrl = "https://api.weixin.qq.com/cgi-bin/token";
        //String requstUrl = "https://api.weixin.qq.com/cgi-bin/menu/get";
        String param = "para={\"phone\":\"15888888888\"}";
        String url = "http://api.weixin.qq.com/services/intfs/vcode.ac";
        String restult = sendPost(url,param);
        System.out.println(restult);
    }
    
    
}