Http Post Get

package com.npnets.http;

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

public class Http {
    public static String sendGet(String url,String jsonStr){
        PrintWriter out = null;
        BufferedReader br = null;
        String result = "";
        try {
            URL realUrl = new URL(url);
            //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
            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
            br = new BufferedReader(new InputStreamReader(connection.getInputStream()));
            String line;
            while((line = br.readLine())!=null){
                result += line;
            }
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException 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 (br != null) {
                    br.close();
                }
            } catch (Exception e2) {
                e2.printStackTrace();
            }
        }
        return result;
    }

    public static String sendPost(String url,String jsonStr){
        PrintWriter out = null;
        BufferedReader br = null;
        String result = "";
        try {
            URL realUrl = new URL(url);
            //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("Content-Type", "text/plain; charset=utf-8");//text/xml text/plain
            connection.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
            connection.setDoOutput(true);
            connection.setDoInput(true);
            //获取URLConnection对象对应的输出流
            out = new PrintWriter(connection.getOutputStream());
            //发送请求参数
            out.print(jsonStr);
            // flush输出流的缓冲
            out.flush();
            //定义BufferedReader输入流来读取URL的响应
            br = new BufferedReader(new InputStreamReader(connection.getInputStream()));
            String line = "";
            while((line = br.readLine())!=null){
                System.out.println(line);
                result += line;
            }
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
             System.out.println("发送 POST 请求出现异常！"+e);
            e.printStackTrace();
        }finally{
            try{
                if(out!=null){
                    out.close();
                }
                if(br!=null){
                    br.close();
                }
            }
            catch(IOException ex){
                ex.printStackTrace();
            }
        }


        return result;
    }


}