Spring Boot拦截器+视图映射器，HandlerInterceptor，InterceptorRegistry ，WebMvcConfigurer

系统管理员 2024-04-18 12:35 59阅读 0赞

## 1.使用拦截器需要实现两个接口 ##

WebMvcConfigurer
    HandlerInterceptor

## 2.实现WebMvcConfigurer接口的类，需要添加@SpringBootConfiguration注解 ##

## 3.现在实现这两个类 ##

MyInterceptors.java

package cn.luoruiyuan.login.config;
    
    import org.springframework.web.servlet.HandlerInterceptor;
    import org.springframework.web.servlet.ModelAndView;
    
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    
    public class MyInterceptors implements HandlerInterceptor {
        @Override
        //进入controller之前进入这个方法
        public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
            System.out.println("进入前。");
            return true;
        }
    
        @Override
        //进入controller之后进入这个方法
        public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
            System.out.println("进入前后。");
        }
    
        @Override
        //方法执行完后
        public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
            System.out.println("方法执行完后。");
        }
    }

MyConfig.java

package cn.luoruiyuan.login.config;
    
    import org.springframework.boot.SpringBootConfiguration;
    import org.springframework.web.servlet.config.annotation.*;
    
    @SpringBootConfiguration
    public class MyConfig implements WebMvcConfigurer{
    
        @Override
        //拦截器
        public void addInterceptors(InterceptorRegistry registry) {
            //addPathPatterns拦截路径
            //excludePathPatterns不拦截路径
            registry.addInterceptor(new MyInterceptors()).addPathPatterns("/hello").excludePathPatterns("/success");
    
            //多个拦截器就添加多个
            //registry.addInterceptor(new MyInterceptors()).addPathPatterns("/hello").excludePathPatterns("/success");
        }
    
        @Override
        //视图映射器
        public void addViewControllers(ViewControllerRegistry registry) {
            //浏览器发送/hello请求来到view
            registry.addViewController("/hello") .setViewName("view");
        }
    
    }

MyConfig.java（第二种写法）

package cn.luoruiyuan.login.config;
    
    import org.springframework.boot.SpringBootConfiguration;
    import org.springframework.context.annotation.Bean;
    import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
    import org.springframework.web.servlet.config.annotation.ViewControllerRegistry;
    import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
    
    @SpringBootConfiguration
    public class MyConfig {
    
        @Bean
        public WebMvcConfigurer myConfiguration(){
            WebMvcConfigurer webMvcConfig=new WebMvcConfigurer(){
    
    
                @Override
                //拦截器
                public void addInterceptors(InterceptorRegistry registry) {
                    //addPathPatterns拦截路径
                    //excludePathPatterns不拦截路径
                    registry.addInterceptor(new MyInterceptors()).addPathPatterns("/hello").excludePathPatterns("/success");
    
                    //多个拦截器就添加多个
                    //registry.addInterceptor(new MyInterceptors()).addPathPatterns("/hello").excludePathPatterns("/success");
                }
    
    
                @Override
                //视图映射器
                public void addViewControllers(ViewControllerRegistry registry) {
                    //浏览器发送/hello请求来到view
                    registry.addViewController("/hello") .setViewName("view");
                }
    
            };
            return webMvcConfig;
        }
    
    
    
    }

4.由于视图映射需要新建一个view.html

<!DOCTYPE>
    <html lang="en" html xmlns:th="http://www.thymeleaf.org" xmlns:tiles="http://www.thymeleaf.org">
    <head>
        <meta charset="UTF-8">
        <title>Title</title>
    </head>
    <body>
    
    <h1>视图映射成功.</h1>
    
    </body>
    </html>

## 5.来查看结果（拦截器与视图映射都生效了） ##

[![26][]][26 1]

# 其他 #

拦截器进行登陆检查  
拦截器

/\*\*  
 \* 登陆检查，  
 \*/  
public class LoginHandlerInterceptor implements HandlerInterceptor \{  
    //目标方法执行之前  
    @Override  
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception \{  
        Object user = request.getSession().getAttribute("loginUser");  
        if(user == null)\{  
            //未登陆，返回登陆页面  
            request.setAttribute("msg","没有权限请先登陆");  
            request.getRequestDispatcher("/index.html").forward(request,response);  
            return false;  
        \}else\{  
            //已登陆，放行请求  
            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 \{  
  
    \}  
\}  
  
/\*\*  
 \* 登陆检查，  
 \*/  
public class LoginHandlerInterceptor implements HandlerInterceptor \{  
    //目标方法执行之前  
    @Override  
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception \{  
        Object user = request.getSession().getAttribute("loginUser");  
        if(user == null)\{  
            //未登陆，返回登陆页面  
            request.setAttribute("msg","没有权限请先登陆");  
            request.getRequestDispatcher("/index.html").forward(request,response);  
            return false;  
        \}else\{  
            //已登陆，放行请求  
            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 \{  
  
    \}  
\}

注册拦截器

//所有的WebMvcConfigurerAdapter组件都会一起起作用  
    @Bean //将组件注册在容器  
    public WebMvcConfigurerAdapter webMvcConfigurerAdapter()\{  
        WebMvcConfigurerAdapter adapter = new WebMvcConfigurerAdapter() \{  
            @Override  
            public void addViewControllers(ViewControllerRegistry registry) \{  
                registry.addViewController("/").setViewName("login");  
                registry.addViewController("/index.html").setViewName("login");  
                registry.addViewController("/main.html").setViewName("dashboard");  
            \}  
  
            //注册拦截器  
            @Override  
            public void addInterceptors(InterceptorRegistry registry) \{  
                //super.addInterceptors(registry);  
                //静态资源；  \*.css , \*.js  
                //SpringBoot已经做好了静态资源映射  
                registry.addInterceptor(new LoginHandlerInterceptor()).addPathPatterns("/\*\*")  
                        .excludePathPatterns("/index.html","/","/user/login");  
            \}  
        \};  
        return adapter;  
    \}

参考：

[https://www.javatt.com/p/25950][https_www.javatt.com_p_25950]

[26]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9maWxlLmx1b3J1aXl1YW4uY24vZmlsZXMvYmxvZy8yMDE4MDkyODE3MzUxMjY2Njk5NS5qcGc?x-oss-process=image/format,png
[26 1]: https://file.luoruiyuan.cn/files/blog/20180928173512666995.jpg
[https_www.javatt.com_p_25950]: https://www.javatt.com/p/25950