Springboot中使用自定义拦截器(springboot2.7.9)-实现登录拦截

ゝ一纸荒年。 2023-09-25 17:03 66阅读 0赞

## 重点：Springboot中使用拦截器需要实现WebMvcConfigurer 接口，重写addInterceptors方法，并注入。 ##

## 1、环境说明 ##

案例中使用IDEA+springboot2.7.9+jdk1.8+mysql版本开发

## 2、创建工程 ##

选择springboot版本+springbweb依赖

![81a8f85289fe48d3a423e37d3624ca25.png][]

## 3、项目创建成功后包依赖如下 ##

<parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.7.9</version>
        <relativePath/> 
    </parent>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
    
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
    
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.16.14</version>
        </dependency>
    </dependencies>

## 4、自定义类实现拦截器HandlerInterceptor 接口 ##

案例说明：访问资源的时候拦截器实现获取session中user的值，如果值不存在就重定向

如果值存在就放行

public class UserInterceptor implements HandlerInterceptor {
        @Override
        public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
            System.out.println("===============拦截器===============");
            //从session中获取user的信息
            User user = (User) request.getSession().getAttribute("user");
            //判断用户是否登录
            if (null == user) {
                response.sendRedirect("user/error");//可以写你想重定向的路径
                //request.setAttribute("msg", "请先登录");
                //request.getRequestDispatcher("/login.html").forward(request, response);
                return false;
            }
            return true;
        }
    }

## 5、将自定义拦截器注入到系统中 ##

需要实现WebMvcConfigurer 类重写addInterceptors方法

重点：自定义配置类InterceptorConfig 需要使用注解@Component进行实例，否则不生效

@Component
    public class InterceptorConfig implements WebMvcConfigurer {
        @Override
        public void addInterceptors(InterceptorRegistry registry) {
            String[] addPathPatterns = {//拦截所有请求
                    "/**"
            };
            String[] excludePathPatterns = {//设置不想拦截的路径
                    "/user/login","/error"
            };
            registry.addInterceptor(new UserInterceptor()).addPathPatterns(addPathPatterns).excludePathPatterns(excludePathPatterns);
        }
    }

## 6、启动类代码 ##

@SpringBootApplication
    @ComponentScan(basePackages ="com.txc")
    public class SpringinterceptorApplication {
        public static void main(String[] args) {
            SpringApplication.run(SpringinterceptorApplication.class, args);
        }
    }

##  ##

## 7、创建测试类 ##

@Controller
    public class UserController {
        @RequestMapping("/test")
        public String test(){
            System.out.println("=========test===========");
            return "";
        }
    }

[81a8f85289fe48d3a423e37d3624ca25.png]: https://img-blog.csdnimg.cn/81a8f85289fe48d3a423e37d3624ca25.png