hunjianghu/yanzheng/Yanzheng.java

package yanzheng;

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;
import java.util.Random;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.alibaba.fastjson.JSONObject;




@WebServlet("/Yanzheng")
public class Yanzheng extends HttpServlet {
	private static final long serialVersionUID = 1L;

    public Yanzheng() {
        super();
        // TODO Auto-generated constructor stub
    }

	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		doPost(request, response);  
	}
	
	public static String SendGET(String url,String param){
		   String result="";//访问返回结果
		   BufferedReader read=null;//读取访问结果
		   URL realurl=null;  
		   URLConnection connection=null;  
		   try {
		    //创建url
		    realurl=new URL(new StringBuffer(url).toString());
		    //打开连接
		    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，获取到cookies等
		             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
		             read = new BufferedReader(new InputStreamReader(
		                     connection.getInputStream(),"UTF-8"));
		             String line;//循环读取
		             while ((line = read.readLine()) != null) {
		                 result += line;
		             }
		   } catch (IOException e) {
		    e.printStackTrace();
		   }finally{
		    if(read!=null){//关闭流
		     try {
		      read.close();
		     } catch (IOException e) {
		      e.printStackTrace();
		     }
		    }
//		    if(connection != null) {  
//		    	connection.  
//		    }  
		   }
		     
		   return result; 
		 }
	
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		response.setHeader("Content - Encoding","utf-8");
        response.setContentType("text/json; charset=utf-8");
		String code =request.getParameter("code");  
		StringBuffer url = new StringBuffer("https://api.weixin.qq.com/sns/jscode2session?");
		url.append("appid=wxdc9f23490d56599c");
		url.append("&secret=c39052978a3e80d55ff53227013384ce");
		url.append("&js_code=");  url.append(code);
		url.append("&grant_type=authorization_code");
		String finalURL = url.toString();  
		String res = SendGET(finalURL, "");  
		JSONObject json = JSONObject.parseObject(res);
		System.out.println(json.toString());  
		int errcode = json.getIntValue("errcode");
		PrintWriter out = response.getWriter();  
		JSONObject toxcx = new JSONObject();  
		if(errcode == 0) {
			String openid = json.getString("openid");  
			String session_key = json.getString("session_key");  
			//插入数据库中还没做
			
			String str="abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
			Random random=new Random();
		    StringBuffer sb=new StringBuffer();
		    for(int i=0;i<20;i++){
		      int number=random.nextInt(62);
		      sb.append(str.charAt(number));
		    }
		    toxcx.put("errcode","成功");  
			toxcx.put("verification",sb.toString());  
			out.println(toxcx.toString());  
			out.flush();
		}
		else if(errcode == -1) {  // 系统繁忙，此时请开发者稍候再试
			toxcx.put("errcode","-1 系统繁忙，请稍候再试");  
			out.println(toxcx.toString());  
			out.flush();
		}
        else if(errcode == 40029) {  // code 无效
        	toxcx.put("errcode","40029 code无效");  
			out.println(toxcx.toString());  
			out.flush();
		}
        else if(errcode == 45011){ //频率限制，每个用户每分钟100次
        	toxcx.put("errcode","45011 操作过于频繁");  
			out.println(toxcx.toString());  
			out.flush();
        }
	}
}