spring boot实现简单的登录拦截

一。思路

1.在pom.xml导入相关包

2.先写个简单的认证适配器（WebSecurityConfig extends WebSecurityConfigurerAdapter），登录拦截后就会跳转到我们想要的页面，不然就会跳转到spring的登录页面

3.写个登录拦截器（LoginInterceptor implements HandlerInterceptor），在请求前（preHandle）根据登录时保存在session attribute里的值进行判断用户是否登录

4.写个拦截器配置（WebConfigurer implements WebMvcConfigurer），注入拦截器（LoginInterceptor ），在addInterceptors方法里进行配置拦截和不用拦截的方法

二。相关代码

1.认证适配器
@Configuration
@EnableWebSecurity
@EnableGlobalMethodSecurity(prePostEnabled = true)
public class WebSecurityConfig extends WebSecurityConfigurerAdapter {

    @Value("${app.basePath:}")
    private String appBasePath;

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        String basePath = StringUtils.trimToEmpty(appBasePath);

        http.authorizeRequests()
                .anyRequest()
                .permitAll();

        http.formLogin()
                .loginPage(basePath + "/console/login.html")
                .defaultSuccessUrl(basePath + "/console/index.html", true)
                .failureForwardUrl("/console/login.html?error=true")
                .permitAll();

        http.logout()
                .logoutSuccessUrl(basePath + "/console/login.html")
                .permitAll();

        http.csrf()
                .disable();

        http.headers()
                .frameOptions()
                .disable();
    }
}

2.登录拦截器

@Component
public class LoginInterceptor implements HandlerInterceptor {

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        HttpSession session = request.getSession();
        String currentAdminId = (String) session.getAttribute("CURRENT_ADMIN_ID");
        if (StringUtils.isNotBlank(currentAdminId)) {
            return true;
        } else {
　　　　　　　　//这里返回要加上全路径，不然会出现 重定向次数过多 的错

　　　　　　　　String path = request.getContextPath();
　　　　　　　　String basePath = request.getScheme() + "://"+ request.getServerName() + ":" + request.getServerPort()+ path + "/console/";
　　　　　　　　response.sendRedirect(basePath+"login.html");
　　　　　　　　return false;

        }
    }

    @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 {

    }
}

3.拦截器配置

@Configuration
public class WebConfigurer implements WebMvcConfigurer {

    @Autowired
    private LoginInterceptor loginInterceptor;

    /**
     * 自定义资源拦截路径可以和springBoot默认的资源拦截一起使用，但是我们如果自己定义的路径与默认的拦截重复，那么我们该方法定义的就会覆盖默认配置
     *
     * @param registry
     * @Return: void
     */
    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
    }

    /**
     * 添加拦截器
     *
     * @param registry
     * @Return: void
     */
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        // addPathPatterns("/**") 表示拦截所有的请求，
        // excludePathPatterns("/login", "/register") 表示不拦截里面的方法
　　　　　//注意：这里如果不放开对image、js、css等静态文件的拦截的话，就会报 重定向次数过多 的错
        registry.addInterceptor(loginInterceptor).addPathPatterns("/**").excludePathPatterns("/login", "/register", "/console/login.html","/console/conLogin.json","/console/login/captcha.png", "/static/**");
    }
}

4.session操作

@UtilityClass
public class SessionTool {

    private static final String ADMIN_ID = "CURRENT_ADMIN_ID";

　　/**
 　　* 获取当前请求
 　　*
 　　* @return 请求信息
 　　*/
　　public static HttpServletRequest getCurrentServletRequest() {
    　　RequestAttributes requestAttributes = RequestContextHolder.currentRequestAttributes();
    　　ServletRequestAttributes servletRequestAttributes = (ServletRequestAttributes) requestAttributes;
    　　return servletRequestAttributes.getRequest();
　　}

    /**
     * 获取当前用户id
     *
     * @param
     * @Return: java.lang.String
     */
    public static String getCurrentAdminId() {
        HttpServletRequest servletRequest = getCurrentServletRequest();

        if (servletRequest != null) {
            HttpSession session = servletRequest.getSession();
            String code = (String) session.getAttribute(ADMIN_ID);
            return code;
        }
        return null;
    }

    /**
     * 设置当前用户id
     *
     * @param code
     * @Return: void
     */
    public static void setCurrentAdminId(String code) {
        HttpServletRequest servletRequest = getCurrentServletRequest();
        if (servletRequest != null) {
            HttpSession session = servletRequest.getSession();
            session.setAttribute(ADMIN_ID, StringUtils.trimToNull(code));
        }
    }

    /**
     * 移除当前用户id
     *
     * @param
     * @Return: void
     */
    public static void delCurrentAdminId() {
        HttpServletRequest servletRequest = getCurrentServletRequest();
        if (servletRequest != null) {
            HttpSession session = servletRequest.getSession();
            session.removeAttribute(ADMIN_ID);
        }
    }

    /**
     * 判断当前用户id是否为空
     *
     * @param
     * @Return: boolean
     */
    public static boolean isSign() {
        return StringUtils.isNotBlank(getCurrentAdminId());
    }
}

参考文件
https://blog.csdn.net/u011972171/article/details/79924133
https://blog.csdn.net/weixin_42740540/article/details/88594441https://blog.csdn.net/weixin_42849689/article/details/89957823