<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.wx.aeolian</groupId>
    <artifactId>com.wx.aeolian</artifactId>
    <version>1.0-SNAPSHOT</version>

    <dependencies>
        <!--servlet-->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.1.0</version>
            <scope>provided</scope>
        </dependency>
        <!--jsp-->
        <dependency>
            <groupId>javax.servlet.jsp</groupId>
            <artifactId>jsp-api</artifactId>
            <version>2.2</version>
            <scope>provided</scope>
        </dependency>
        <!--jstl-->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>jstl</artifactId>
            <version>1.2</version>
            <scope>runtime</scope>
        </dependency>
        <!--加密工具-->
        <dependency>
            <groupId>commons-codec</groupId>
            <artifactId>commons-codec</artifactId>
            <version>1.12</version>
        </dependency>
    </dependencies>

    <!--编码方式UTF-8-->
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.basedir>D:\ProgramFiles_QY\IdeaProjects\WxAeolian</project.basedir>
    </properties>

    <build>
        <plugins>
            <!--编译Compile,使用JDK1.7开发-->
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.3</version>
                <configuration>
                    <source>1.7</source>
                    <target>1.7</target>
                </configuration>
            </plugin>
            <!--打包时跳过测试-->
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-surefire-plugin</artifactId>
                <version>2.18.1</version>
                <configuration>
                    <skipTests>true</skipTests>
                </configuration>
            </plugin>
            <!--Tomcat-->
            <plugin>
                <groupId>org.apache.tomcat.maven</groupId>
                <artifactId>tomcat7-maven-plugin</artifactId>
                <version>2.2</version>
                <configuration>
                    <path>/${project.artifactId}</path>
                </configuration>
            </plugin>

        </plugins>
    </build>
</project>

package com.aeolian.core;

import org.apache.commons.codec.digest.DigestUtils;
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 java.io.IOException;
import java.util.*;

@WebServlet("/wxCore")
public class WxServlet extends HttpServlet{
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws IOException {
        try {
            doPost(req,resp);
        } catch (ServletException e) {
            e.printStackTrace();
        }
    }

    /*1）将token、timestamp、nonce三个参数进行字典序排序
     *2）将三个参数字符串拼接成一个字符串进行sha1加密
     *3）开发者获得加密后的字符串可与signature对比，标识该请求来源于微信*/
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String signature = req.getParameter("signature");
        String timestamp = req.getParameter("timestamp");
        String nonce = req.getParameter("nonce");
        String echostr = req.getParameter("echostr");
        String token = "微信公众平台中设置的token";    //微信公众平台中配置
        /*1）将token、timestamp、nonce三个参数进行字典序排序*/
        String[] str = { token, timestamp, nonce };
        Arrays.sort(str); // 字典序排序
        String sortStr = str[0] + str[1] + str[2];  //排序后拼接
        /*2）将三个参数字符串拼接成一个字符串进行sha1加密*/
        String digest = DigestUtils.sha1Hex(sortStr);

        /*System.out.println("signature: "+signature);
        System.out.println("timestamp: "+timestamp);
        System.out.println("nonce: "+nonce);
        System.out.println("echostr: "+echostr);
        System.out.println("nosha1: "+sortStr);
        System.out.println("digest: "+digest);*/
        /*3)校验*/
        String result = "";
        if (digest.equals(signature)){   //与signature对比，标识该请求来源于微信
            result = echostr;  //如果是,返回echostr
        }

        resp.resetBuffer();
        resp.setContentType("text/html;charset=utf-8");
        resp.getOutputStream().write(result.getBytes("utf-8"));
        resp.getOutputStream().flush();
    }
}