<!--    html登录代码    -->

        <div class="box">

            <div class="title">登录</div>

            <div class="input">

                <label for="name">用户名</label>

                <input type="text" name="name" id="name">

                <span class="spin"></span>

            </div>

            <div class="input">

                <label for="pass">密码</label>

                <input type="password" name="pass" id="pass">

                <span class="spin"></span>

            </div>

            <div class="button login">

                <button>

                    <span>登录</span>

                    <i class="fa fa-check"></i>

                </button>

            </div>

            <a href="javascript:" class="pass-forgot">忘记密码？</a>

        </div>

<!-- javasript 登录代码 -->
$(".button").click(function(e) {

      $("button", this).addClass('active');

      if ($(".button").hasClass("login")){

         $.ajax({

            url:"/cch/dologin",

            type:"POST",

            data:{

               name:$("#name").serialize(),

               pass:$("#pass").serialize(),

            },

            success:function (result) {

               if(result.code==100){

                  window.location.href="/cch/main";

               }else {

                  alert(result.extendInfo.login_error);

               }

            }

         })

      }

   })

//JsonMsg工具类
public class JsonMsg {

    private int code;

    private String msg;

    private Map<String,Object> extendInfo = new HashMap<String, Object>();

    public int getCode() {

        return code;

    }

    public void setCode(int code) {

        this.code = code;

    }

    public String getMsg() {

        return msg;

    }

    public void setMsg(String msg) {

        this.msg = msg;

    }

    public Map<String, Object> getExtendInfo() {

        return extendInfo;

    }

    public void setExtendInfo(Map<String, Object> extendInfo) {

        this.extendInfo = extendInfo;

    }

    public static JsonMsg success(){

        JsonMsg res = new JsonMsg();

        res.setCode(100);

        res.setMsg("操作成功");

        return res;

    }

    public static JsonMsg fail(){

        JsonMsg res = new JsonMsg();

        res.setCode(200);

        res.setMsg("操作失败");

        return res;

    }

    public JsonMsg addInfo(String key,Object object){

        this.extendInfo.put(key,object);

        return this;

    }

}

/**
* controller
* 判断用户名和密码是否正确
*/
　　@RequestMapping(value = "/cch/dologin",method = RequestMethod.POST)

    @ResponseBody

    public JsonMsg dologin(HttpServletRequest request){

        String username = request.getParameter("name");

        String password = request.getParameter("pass");

        System.out.println(username+" "+password);

        if (!"name=admin".equals(username) || !"pass=123".equals(password)){

            return JsonMsg.fail().addInfo("login_error","用户名或密码错误");

        }

        request.getSession().setAttribute("islogin","true");//如果正确，则在seesion里添加判断属性，可供拦截器判断是否登录过

        return JsonMsg.success();

    }

//自定义拦截器
//如果未登录则跳回登录页

public class SysInterceptor extends HandlerInterceptorAdapter {

    /**

     * 进入拦截器后首先进入的方法

     * 返回false则不再继续执行

     * 返回true则继续执行

     */

    @Override

    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {

        System.out.println("我是拦截器：我进来了");

        HttpSession session = request.getSession();

        String islogin = (String)session.getAttribute("islogin");

        if(islogin==null){

            System.out.println("用户没有登录");

            response.sendRedirect("/cch/login");

            return false;

        }

        System.out.println("用户已登录");

        return true;

    }

    @Override

    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {

    }

    @Override

    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {

    }

}

//把拦截器添加到springboot中

@Configuration

public class SessionConfig implements WebMvcConfigurer {

    @Override

    public void addInterceptors(InterceptorRegistry registry) {
//拦截有 "/cch" 前缀的路径，除了 "/cch/login","/cch/dologin"

        registry.addInterceptor(new SysInterceptor()).excludePathPatterns("/cch/login","/cch/dologin").addPathPatterns("/cch/**");

    }

}