1、前端傳資料給前端

　　把資料放到cookie中或者localStorage

登入JS

    /**
     * 登入操作
     */
    function checkCode(email,code){
        $.post("checkCode?email="+email+"&code="+code,function (response){
            console.log(response.status);
            //驗證碼錯誤
            if (response.status == 3002) {
                
 
//顯示
                alert(response.message);
                location.replace("login.html");
            }
            if (response.status == 2000) {
                //跳轉頁面 獲取郵箱驗證碼
                window.localStorage.setItem("admin",JSON.stringify(response.data))
                location.replace("/toMain");
            }
        });
    }
 

主頁JS

    $(function (){
        var admin = JSON.parse(localStorage.getItem("admin"))
        console.log(admin)
        if (admin!=null){
            if (admin.adminAvatar){
                $("#adminAvatar").attr("src",admin.adminAvatar)
            }
            if (admin.adminName){
                $(
 
"#adminName").text(admin.adminName)
            }
        }
    })

2、登入攔截

　　把使用者資訊儲存到session返回給前端，前端每次請求時後臺檢測session中有沒有使用者資訊，有就允許請求，沒有就丟擲自定義異常，返回一個狀態碼給前端，前端檢測到這個狀態碼會重定向到指定頁

　　注意：非同步請求重定向失效

1、把使用者資訊儲存到session返回給前端

Controller層程式碼

    /**
     * 輸入驗證碼，驗證登入
     *
     * @param email
     * @param code
     * @return
     */
    @PostMapping("checkCode")
    @ResponseBody
    public AjaxResult checkCode(HttpServletRequest request, String email, String code) {
        String s = jedis.get(email);
        Admin admin = adminService.findAdminByEmail(email);
        if (code.equalsIgnoreCase(s)) {
            //登入成功後，手動刪除
            jedis.del(email);
            //把使用者資訊儲存到session中
            request.getSession().setAttribute("admin",admin);
            return AjaxResult.success(admin);
        } else {
            return AjaxResult.error(AjaxStatus.CODE_CHECK_ERROR);
        }
    }

2、建立攔截器，檢測session中的資料

public class LonginInterceptor implements HandlerInterceptor {

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        Object admin = request.getSession().getAttribute("admin");
        if (admin==null) {
            throw new NotLoginException(AjaxStatus.NOT_LOGIN);
        }

        return true;
    }
}

3、在springmvc配置攔截器

<!--    攔截器-->
    <mvc:interceptors>
        <mvc:interceptor>
            <mvc:mapping path="/**"/>
            <mvc:exclude-mapping path="/dist/**"/>
            <mvc:exclude-mapping path="/plugins/**"/>
            <mvc:exclude-mapping path="/login.html"/>
            <mvc:exclude-mapping path="/WEB-INF/pages/**"/>
            <mvc:exclude-mapping path="/WEB-INF/template/**"/>
            <mvc:exclude-mapping path="/getCode"/>
            <mvc:exclude-mapping path="/toCode"/>
            <mvc:exclude-mapping path="/checkCode"/>
            <mvc:exclude-mapping path="/toMain"/>
            <mvc:exclude-mapping path="/sendActiveEmail"/>
            <mvc:exclude-mapping path="/*/doActive"/>
            <mvc:exclude-mapping path="/success"/>
            <mvc:exclude-mapping path="/"/>
            <bean class="top.ftime.wk.interceptor.LonginInterceptor"/>
        </mvc:interceptor>
    </mvc:interceptors>

4、設定沒有登入的狀態碼

public enum AjaxStatus {
    /**
     * 狀態碼
     */
    OK(2000,"操作成功"),
    ERROR(5000,"操作失敗"),
    //登入相關狀態碼
    EMAIL_NOT_FOUND(3000,"郵箱錯誤"),
    ADMIN_NOT_ACTIVE(3001,"使用者未啟用"),
    CODE_CHECK_ERROR(3002,"驗證碼錯誤"),
    ACTIVE_ERROR(3003,"郵箱啟用失敗或已啟用"),
    ACTIVE_OK(2001,"啟用郵件已傳送，注意查收"),
    NOT_LOGIN(4004,"登入過期，請重新登入"),
    ;

    private int status;

    private String message;

    AjaxStatus(int status, String message) {
        this.status = status;
        this.message = message;
    }

    public int getStatus() {
        return status;
    }

    public void setStatus(int status) {
        this.status = status;
    }

    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }
}

5、使用自定義異常

public class NotLoginException extends RuntimeException{

    private AjaxStatus ajaxStatus;

    public AjaxStatus getAjaxStatus() {
        return ajaxStatus;
    }

    public void setAjaxStatus(AjaxStatus ajaxStatus) {
        this.ajaxStatus = ajaxStatus;
    }

    public NotLoginException(AjaxStatus ajaxStatus) {
        this.ajaxStatus = ajaxStatus;
    }
}

6、捕捉異常，返回給頁面一個狀態碼

@ControllerAdvice
public class MyHandler {

    @ExceptionHandler(NotLoginException.class)
    @ResponseBody
    public AjaxResult myHandler(NotLoginException e){
        return AjaxResult.error(e.getAjaxStatus());
    }
}

7、設定全域性函式，檢測狀態碼

$(function () {
//全域性函式
    $.ajaxSetup({
        global: true,
        complete: function (a, b, c) {
            console.log(a.responseJSON.status)
            if (a.responseJSON.status == 4004) {
                alert(a.responseJSON.message);
                parent.location.replace("/");
            }
        }
    })
｝