运用Java对微信公众平台二次开发技术——开发者模式接入

package org.hjj.servlet;

import java.io.IOException;
import java.io.PrintWriter;
import java.io.Writer;

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 org.hjj.service.CoreService;
import org.hjj.util.CheckUtil;


@WebServlet("/wx.do")
public class WeixinServlet extends HttpServlet {
   	private static final long serialVersionUID = 1L;
 
    protected void doGet(HttpServletRequest request,  
            HttpServletResponse response) throws ServletException, IOException {  
        String signature = request.getParameter("signature");// 微信加密签名  
        String timestamp = request.getParameter("timestamp");// 时间戳  
        String nonce = request.getParameter("nonce");// 随机数  
        String echostr = request.getParameter("echostr");// 随机字符串  
        Writer out = response.getWriter();  
        System.out.println("收到验证请求：");  
        System.out.println("　　signature="+signature);  
        System.out.println("　　timestamp="+timestamp);  
        System.out.println("　　nonce="+nonce);  
        System.out.println("　　echostr="+echostr);  
        if(signature==null || timestamp==null || nonce==null || echostr==null){  
            //这几个参数为空时，排序会报错。  
            out.write("parameter is null!");  
            System.out.println("failed");
        }  
        else{  
            if (CheckUtil.checkSignature(signature, timestamp, nonce)) {  
                out.write(echostr);// 请求验证成功，返回随机码  
                System.out.println("success");
            } else {  
            	System.out.println("check failed");
                out.write("check error!");  
            }  
        }  
        out.flush();  
        out.close();  
    }
	@Override
	protected void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
	        request.setCharacterEncoding("UTF-8");  
	        response.setCharacterEncoding("UTF-8");
	        PrintWriter out = response.getWriter();  
	        	String respXml = CoreService.processRequest(request);
	        	out.print(respXml);  
	        out.close();  
	        out= null;
	        
	}     
    
    
}

package org.hjj.util;

import java.util.Arrays;

public class CheckUtil {
	
	private static final String token="写你自己的token";
	public static boolean checkSignature(String signature,String timestamp,String nonce ){
		String [] arr = new String []{token,timestamp,nonce};
		Arrays.sort(arr);
		
		StringBuffer content = new StringBuffer();
		for (int i = 0; i < arr.length; i++) {
			content.append(arr[i]);
		}
		
		 String temp = SHA1.encode(content.toString());  
		return temp.equals(signature);
	}
	
}

package org.hjj.util;

import java.security.MessageDigest;

/**
 * <p>Title: SHA1算法</p>
 *
 * @author qsyang<yangqisheng274@163.com>
 */
public final class SHA1 {
    private static final char[] HEX_DIGITS = {‘0‘, ‘1‘, ‘2‘, ‘3‘, ‘4‘, ‘5‘,
                           ‘6‘, ‘7‘, ‘8‘, ‘9‘, ‘a‘, ‘b‘, ‘c‘, ‘d‘, ‘e‘, ‘f‘};

    /**
     * Takes the raw bytes from the digest and formats them correct.
     *
     * @param bytes the raw bytes from the digest.
     * @return the formatted bytes.
     */
    private static String getFormattedText(byte[] bytes) {
        int len = bytes.length;
        StringBuilder buf = new StringBuilder(len * 2);
        // 把密文转换成十六进制的字符串形式
        for (int j = 0; j < len; j++) {
            buf.append(HEX_DIGITS[(bytes[j] >> 4) & 0x0f]);
            buf.append(HEX_DIGITS[bytes[j] & 0x0f]);
        }
        return buf.toString();
    }

    public static String encode(String str) {
        if (str == null) {
            return null;
        }
        try {
            MessageDigest messageDigest = MessageDigest.getInstance("SHA1");
            messageDigest.update(str.getBytes());
            return getFormattedText(messageDigest.digest());
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }
}