基於springboot配置攔截器

1.編寫攔截器類：

public class loginHandlerInterceptor implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        HttpSession session = request.getSession();
        if(session.getAttribute("username")==null){
            request.setAttribute("msg","請先登錄");
            request.getRequestDispatcher("/").forward(request,response);
            return  false;
        }
        else return true;
    }
}

2.在mvc配置類中添加攔截器

//導入配置
@Configuration
//繼承WebMvcConfigurer
public class mvcConfig implements WebMvcConfigurer {

    //添加自定義攔截器
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(new loginHandlerInterceptor()).addPathPatterns("/**")
                //配置不攔截的路徑
                .excludePathPatterns("/","/login","/css/**","/js/**","/fonts/**","images/**");
    }
}