SpringMVC——拦截器Interceptor

m0_63544124

已于 2022-08-07 11:15:07 修改

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文章标签： java 开发语言

于 2022-06-04 10:13:55 首次发布

本文链接：https://blog.youkuaiyun.com/m0_63544124/article/details/125110936

版权

1.拦截器概念编辑

2.入门案例

2.1定义 ProjectInterceptor类，实现HandlerInterceptor接口，配上@Component

2.2配置类SpringMvcSupport，继承WebMvcConfigurationSupport，配上@Configuration

3.1 路径可以通过可变参数设置多个 "/books","/books/*

1.拦截器概念

2.入门案例

2.1定义 ProjectInterceptor类，实现HandlerInterceptor接口，配上@Component

@Component//要受Spring容器的管理
public class ProjectInterceptor implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("preHandle");
        return true;
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        System.out.println("postHandle");
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        System.out.println("afterCompletion");
    }
}

2.2配置类SpringMvcSupport，继承WebMvcConfigurationSupport，配上@Configuration

@Configuration
public class SpringMvcSupport extends WebMvcConfigurationSupport {

    @Autowired
    private ProjectInterceptor projectInterceptor;

    @Override
    //放行静态资源
    protected void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/pages/**").addResourceLocations("/pages/");
    }

    @Override
    //拦截器
    protected void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(projectInterceptor).addPathPatterns("/books");
    }
}

2.3加上包扫描


@Configuration
@ComponentScan({"com.controller","com.config"})
@EnableWebMvc
public class SpringMvcConfig{

}

2.4测试

拦截生效

拦截不生效

3.拦截器配置文件

3.1 路径可以通过可变参数设置多个 "/books","/books/*

@Configuration
public class SpringMvcSupport extends WebMvcConfigurationSupport {

    @Autowired
    private ProjectInterceptor projectInterceptor;

    @Override
    //放行静态资源
    protected void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/pages/**").addResourceLocations("/pages/");
    }

    @Override
    //拦截器
    protected void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(projectInterceptor).addPathPatterns("/books","/books/*");
    }
}

拦截生效

3.2 简化写法

不用写SpringMvcSupport类，也不用扫描到"com.config"

直接让SpringMvcConfig继承WebMvcConfigurer接口

@Configuration
@ComponentScan("com.controller")
@EnableWebMvc
//实现WebMvcConfigurer接口可以简化开发，但具有一定的侵入性
public class SpringMvcConfig implements WebMvcConfigurer {
    @Autowired
    private ProjectInterceptor projectInterceptor;

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(projectInterceptor).addPathPatterns("/books", "/books/*");
    }
}

4.拦截器参数

@Component//要受Spring容器的管理
public class ProjectInterceptor implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        //1.requst
        String header = request.getHeader("Connection");
        System.out.println(header);//keep-alive

        //2.handlerMethod
        HandlerMethod handlerMethod = (HandlerMethod) handler;
        //获取到反射中的方法对象
        Method method = handlerMethod.getMethod();
        String name = method.getName();
        System.out.println(name);//getById

        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 {

    }
}

5.拦截器工作流程

5.1流程分析

@Component//要受Spring容器的管理
public class ProjectInterceptor implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("preHandle");
        return false;
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        System.out.println("postHandle");
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        System.out.println("afterCompletion");
    }
}

5.2拦截器链

5.2.1定义两个拦截器类

@Component//要受Spring容器的管理
public class ProjectInterceptor implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("preHandle...");
        return true;
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        System.out.println("postHandle...");
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        System.out.println("afterCompletion...");
    }
}


@Component//要受Spring容器的管理
public class ProjectInterceptor2 implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("preHandle2...");
        return true;
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        System.out.println("postHandle2...");
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        System.out.println("afterCompletion2...");
    }
}

5.2.2配置两个拦截器类


@Configuration
public class SpringMvcSupport extends WebMvcConfigurationSupport {

    @Autowired
    private ProjectInterceptor projectInterceptor;
    @Autowired
    private ProjectInterceptor2 projectInterceptor2;

    @Override
    //拦截器
    protected void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(projectInterceptor).addPathPatterns("/books","/books/*");
        registry.addInterceptor(projectInterceptor2).addPathPatterns("/books","/books/*");
    }
}