Java 代码实现POST/GET请求

方式一

package com.cyb.util;

import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
import java.util.HashMap;
import java.util.Map;

public class Util {
    public static final String DEF_CHATSET = "UTF-8";
    public static final int DEF_CONN_TIMEOUT = 30000;
    public static final int DEF_READ_TIMEOUT = 30000;
    public static String userAgent =  "Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/29.0.1547.66 Safari/537.36";
 
    //配置您申请的KEY
    public static final String APPKEY ="*************************";
    
    /**
    *
    * @param strUrl 请求地址
    * @param params 请求参数
    * @param method 请求方法
    * @return  网络请求字符串
    * @throws Exception
    */
   public static String net(String strUrl, Map params,String method) throws Exception {
       HttpURLConnection conn = null;
       BufferedReader reader = null;
       String rs = null;
       try {
           StringBuffer sb = new StringBuffer();
           if(method==null || method.equals("GET")){
               strUrl = strUrl+"?"+urlencode(params);
           }
           URL url = new URL(strUrl);
           conn = (HttpURLConnection) url.openConnection();
           if(method==null || method.equals("GET")){
               conn.setRequestMethod("GET");
           }else{
               conn.setRequestMethod("POST");
               conn.setDoOutput(true);
           }
           conn.setRequestProperty("User-agent", userAgent);
           conn.setUseCaches(false);
           conn.setConnectTimeout(DEF_CONN_TIMEOUT);
           conn.setReadTimeout(DEF_READ_TIMEOUT);
           conn.setInstanceFollowRedirects(false);
           conn.connect();
           if (params!= null && method.equals("POST")) {
               try {
                   DataOutputStream out = new DataOutputStream(conn.getOutputStream());
                       out.writeBytes(urlencode(params));
               } catch (Exception e) {
                   // TODO: handle exception
               }
           }
           InputStream is = conn.getInputStream();
           reader = new BufferedReader(new InputStreamReader(is, DEF_CHATSET));
           String strRead = null;
           while ((strRead = reader.readLine()) != null) {
               sb.append(strRead);
           }
           rs = sb.toString();
       } catch (IOException e) {
           e.printStackTrace();
       } finally {
           if (reader != null) {
               reader.close();
           }
           if (conn != null) {
               conn.disconnect();
           }
       }
       return rs;
   }

   //将map型转为请求参数型
   public static String urlencode(Map<String,Object>data) {
       StringBuilder sb = new StringBuilder();
       for (Map.Entry i : data.entrySet()) {
           try {
               sb.append(i.getKey()).append("=").append(URLEncoder.encode(i.getValue()+"","UTF-8")).append("&");
           } catch (UnsupportedEncodingException e) {
               e.printStackTrace();
           }
       }
       return sb.toString();
   }
}

方式二

    /**
     * 向指定的地址发送GET请求
     * @param url
     * @return
     */
    public static String get(String url) {
        try {
            URL urlObjUrl=new URL(url);
            //打开链接
            URLConnection connection =urlObjUrl.openConnection();
            InputStream iStream=connection.getInputStream();
            byte[] b=new byte[1024];
            int len;
            StringBuilder sb=new StringBuilder();
            while ((len=iStream.read(b))!=-1) {
                sb.append(new String(b,0,len));
            }
            return sb.toString();
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        
        return null;
    }

方式三

    /**
     * 向指定的地址发送一个POST请求
     * @param url 请求地址
     * @param params 请求数据
     * @return
     */
    public static String post(String url,String params) {
        try {
            URL urlObjUrl=new URL(url);
            //打开链接
            URLConnection connection =urlObjUrl.openConnection();
            //要发送数据出去，必须要设置为可发送数据状态
            connection.setDoOutput(true);
            OutputStream os=connection.getOutputStream();
            //写出数据
            os.write(params.getBytes());
            os.close();
            //获取输入流，读取数据
            InputStream iStream=connection.getInputStream();
            byte[] b=new byte[1024];
            int len;
            StringBuilder sb=new StringBuilder();
            while ((len=iStream.read(b))!=-1) {
                sb.append(new String(b,0,len));
            }
            return sb.toString();
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return null;
    }