微信公共平台(一)网址接入

package com.chaowen;

import java.io.IOException;
import java.io.PrintWriter;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;

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

/**
 * Servlet implementation class WeiXinServlet
 */
public class WeiXinServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;
	public static final String Token = "token";   



	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		this.doPost(request, response);
	}


	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		//response.setContentType("text/xml;charset=utf-8");
		response.setCharacterEncoding("UTF-8"); 
		PrintWriter   out   =   response.getWriter();

		String signature = request.getParameter("signature");
		String timestamp = request.getParameter("timestamp");
		String nonce = request.getParameter("nonce");
		String[] ArrTmp = { Token, timestamp, nonce };
		Arrays.sort(ArrTmp);
		StringBuffer sb = new StringBuffer();
		for (int i = 0; i < ArrTmp.length; i++) {
			sb.append(ArrTmp[i]);
		}
		String pwd = Encrypt(sb.toString());
		String echostr = request.getParameter("echostr");
		System.out.println("pwd=="+pwd);
		System.out.println("echostr=="+echostr);
		if(pwd.equals(signature)){
			if(!"".equals(echostr) && echostr != null){
				response.getWriter().print(echostr);
			}
		}

		out.flush();
		out.close();
	}

	public String Encrypt(String strSrc) {
		MessageDigest md = null;
		String strDes = null;

		byte[] bt = strSrc.getBytes();
		try {
			md = MessageDigest.getInstance("SHA-1");
			md.update(bt);
			strDes = bytes2Hex(md.digest()); //to HexString
		} catch (NoSuchAlgorithmException e) {
			System.out.println("Invalid algorithm.");
			return null;
		}
		return strDes;
	}

	public String bytes2Hex(byte[] bts) {
		String des = "";
		String tmp = null;
		for (int i = 0; i < bts.length; i++) {
			tmp = (Integer.toHexString(bts[i] & 0xFF));
			if (tmp.length() == 1) {
				des += "0";
			}
			des += tmp;
		}
		return des;
	}
}