java的POST和GET请求

java的get和post方式请求：

package com.jfpay.util.http;

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;

import java.util.ArrayList;

import java.util.List;

 

import org.apache.http.HttpEntity;

import org.apache.http.NameValuePair;

import org.apache.http.client.entity.UrlEncodedFormEntity;

import org.apache.http.client.methods.CloseableHttpResponse;

import org.apache.http.client.methods.HttpPost;

import org.apache.http.impl.client.CloseableHttpClient;

import org.apache.http.impl.client.HttpClients;

import org.apache.http.message.BasicNameValuePair;

import org.apache.http.util.EntityUtils;

import org.springframework.expression.ParseException;

public class HttpRequest {

 

    /**

     * 向指定 URL 发送POST方法的请求

     * 

     * @param url

     *            发送请求的 URL

     * @param param

     *            

     * @return 所代表远程资源的响应结果

     */

    public static String readPost(String url, String xml) throws ParseException, IOException{

 

String body = "";  

//创建httpclient对象  

CloseableHttpClient client = HttpClients.createDefault();  

//创建post方式请求对象  

HttpPost httpPost = new HttpPost(url);  

 

//装填参数  

List<NameValuePair> nvps = new ArrayList<NameValuePair>();  

nvps.add(new BasicNameValuePair("xml", xml));  

//设置参数到请求对象中  

httpPost.setEntity(new UrlEncodedFormEntity(nvps, "utf-8"));  

 

//设置header信息  

//指定报文头【Content-type】、【User-Agent】  

httpPost.setHeader("Content-type", "application/x-www-form-urlencoded;charset=utf-8");  

httpPost.setHeader("User-Agent", "Mozilla/4.0 (compatible; MSIE 5.0; Windows NT; DigExt)");  

 

//执行请求操作，并拿到结果（同步阻塞）  

CloseableHttpResponse response = client.execute(httpPost);  

//获取结果实体  

HttpEntity entity = response.getEntity();  

if (entity != null) {  

//按指定编码转换结果实体为String类型  

body = EntityUtils.toString(entity, "utf-8");  

}  

EntityUtils.consume(entity);  

//释放链接  

response.close();  

return body; 

   

    }   

 

    public static String sendPost(String url,String xml) throws IOException {

        // Post请求的url，与get不同的是不需要带参数

        URL postUrl = new URL(url);

        // 打开连接

        HttpURLConnection connection = (HttpURLConnection) postUrl.openConnection();     

        // 设置是否向connection输出，因为这个是post请求，参数要放在

        // http正文内，因此需要设为true

        connection.setDoOutput(true);

        // Read from the connection. Default is true.

        connection.setDoInput(true);

        // 默认是 GET方式

        connection.setRequestMethod("POST");

        // 设置字符编码

        connection.setRequestProperty("Accept-Charset", "utf-8");

        // Post 请求不能使用缓存

        connection.setUseCaches(false);      

        connection.setInstanceFollowRedirects(true);

        // 配置本次连接的Content-type，配置为application/x-www-form-urlencoded的

        // 意思是正文是urlencoded编码过的form参数，下面我们可以看到我们对正文内容使用URLEncoder.encode

        // 进行编码

        connection.setRequestProperty("Content-Type","application/x-www-form-urlencoded;charset=utf-8");

        connection.setRequestProperty("contentType", "utf-8");

        // 连接，从postUrl.openConnection()至此的配置必须要在connect之前完成，

        // 要注意的是connection.getOutputStream会隐含的进行connect。

        connection.connect();

        DataOutputStream out = new DataOutputStream(connection

                .getOutputStream());

        // The URL-encoded contend

        // 正文，正文内容其实跟get的URL中 '? '后的参数字符串一致

        String content = "xml=" + URLEncoder.encode(xml, "utf-8");

        // DataOutputStream.writeBytes将字符串中的16位的unicode字符以8位的字符形式写到流里面

        out.writeBytes(content);

        out.flush();

        out.close(); 

        BufferedReader reader = new BufferedReader(new InputStreamReader(connection.getInputStream()));

        String line;

        String response = null;

        while ((line = reader.readLine()) != null){

        response=line;

        }

        reader.close();

        connection.disconnect();

return response;

 

    }

}