spring boot 2.x静态资源会被HandlerInterceptor拦截的原因和解决方法

在spring boot 1.5.x中,resources/static目录下的静态资源可以直接访问,并且访问路径上不用带static,比如静态资源放置位置如下图所示:

静态资源目录结构

那么访问静态资源的路径可以是:

当有配置自定义HandlerInterceptor拦截器时,请求以上静态资源路径不会被拦截。自定义HandlerInterceptor拦截器源码如下:

package com.itopener.demo.config;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;


public class LoginRequiredInterceptor extends HandlerInterceptorAdapter {

    private final Logger logger = LoggerFactory.getLogger(LoginRequiredInterceptor.class);

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
            throws Exception {
        logger.info(request.getRequestURI());
        return super.preHandle(request, response, handler);
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex)
            throws Exception {
        logger.info(request.getRequestURI());
        super.afterCompletion(request, response, handler, ex);
    }
}

配置如下:

package com.itopener.demo.config;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;


@Configuration
public class WebMvcConfiguration extends WebMvcConfigurerAdapter {

    private final Logger logger = LoggerFactory.getLogger(WebMvcConfiguration.class);

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        logger.info("add interceptors");
        registry.addInterceptor(new LoginRequiredInterceptor());
    }

}

访问静态资源时路径上不用加static目录:

spring boot 1.5.x访问静态资源

当spring boot版本升级为2.x时,访问静态资源就会被HandlerInterceptor拦截

HandlerInterceptor拦截静态资源日志

这样对于利用HandlerInterceptor来处理访问权限或其他相关的功能就会受影响,跟踪源码查看原因,是因为spring boot 2.x依赖的spring 5.x版本,相对于spring boot 1.5.x依赖的spring 4.3.x版本而言,针对资源的拦截器初始化时有区别,具体源码在WebMvcConfigurationSupport中,spring 4.3.x源码如下:

/**
 * Return a handler mapping ordered at Integer.MAX_VALUE-1 with mapped
 * resource handlers. To configure resource handling, override
 * {@link #addResourceHandlers}.
 */
@Bean
public HandlerMapping resourceHandlerMapping() {
    ResourceHandlerRegistry registry = new ResourceHandlerRegistry(this.applicationContext,
                this.servletContext, mvcContentNegotiationManager());
    addResourceHandlers(registry);

    AbstractHandlerMapping handlerMapping = registry.getHandlerMapping();
    if (handlerMapping != null) {
        handlerMapping.setPathMatcher(mvcPathMatcher());
        handlerMapping.setUrlPathHelper(mvcUrlPathHelper());
        // 此处固定添加了一个Interceptor
        handlerMapping.setInterceptors(new ResourceUrlProviderExposingInterceptor(mvcResourceUrlProvider()));
        handlerMapping.setCorsConfigurations(getCorsConfigurations());
        }
    else {
        handlerMapping = new EmptyHandlerMapping();
    }
    return handlerMapping;
}

而spring 5.x的源码如下:

/**
 * Return a handler mapping ordered at Integer.MAX_VALUE-1 with mapped
 * resource handlers. To configure resource handling, override
 * {@link #addResourceHandlers}.
 */
@Bean
public HandlerMapping resourceHandlerMapping() {
    Assert.state(this.applicationContext != null, "No ApplicationContext set");
    Assert.state(this.servletContext != null, "No ServletContext set");

    ResourceHandlerRegistry registry = new ResourceHandlerRegistry(this.applicationContext,
                this.servletContext, mvcContentNegotiationManager(), mvcUrlPathHelper());
    addResourceHandlers(registry);

    AbstractHandlerMapping handlerMapping = registry.getHandlerMapping();
    if (handlerMapping != null) {
        handlerMapping.setPathMatcher(mvcPathMatcher());
        handlerMapping.setUrlPathHelper(mvcUrlPathHelper());
        // 此处是将所有的HandlerInterceptor都添加了(包含自定义的HandlerInterceptor)
        handlerMapping.setInterceptors(getInterceptors());
        handlerMapping.setCorsConfigurations(getCorsConfigurations());
    }
    else {
        handlerMapping = new EmptyHandlerMapping();
    }
    return handlerMapping;
}

/**
 * Provide access to the shared handler interceptors used to configure
 * {@link HandlerMapping} instances with. This method cannot be overridden,
 * use {@link #addInterceptors(InterceptorRegistry)} instead.
 */
protected final Object[] getInterceptors() {
    if (this.interceptors == null) {
        InterceptorRegistry registry = new InterceptorRegistry();
        // 此处传入新new的registry对象,在配置类当中设置自定义的HandlerInterceptor后即可获取到
        addInterceptors(registry);
        registry.addInterceptor(new ConversionServiceExposingInterceptor(mvcConversionService()));
        registry.addInterceptor(new ResourceUrlProviderExposingInterceptor(mvcResourceUrlProvider()));
        this.interceptors = registry.getInterceptors();
    }
    return this.interceptors.toArray();
}

从源码当中可以看出,使用spring 5.x时,静态资源也会执行自定义的拦截器,因此在配置拦截器的时候需要指定排除静态资源的访问路径,即配置改为如下即可:

package com.itopener.demo.config;

import java.util.Arrays;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

/**
 * @author fuwei.deng
 * @date 2018年4月13日 下午3:32:54
 * @version 1.0.0
 */
@Configuration
public class WebMvcConfiguration implements WebMvcConfigurer {

    private final Logger logger = LoggerFactory.getLogger(WebMvcConfiguration.class);

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        logger.info("add interceptors");
        registry.addInterceptor(new LoginRequiredInterceptor()).excludePathPatterns(Arrays.asList("/views/**", "/res/**"));
    }
}

这样就可以和spring boot 1.5.x一样的方式使用了。不过从源码当中可以看出,每个静态资源的请求都会被自定义Interceptor拦截,只是通过访问路径判断后不会执行拦截器的内容,所以spring 5.x相对于spring 4.3.x而言,这部分处理的性能会更低一些

说明:

  • 本文中测试使用的具体版本:

    • spring-boot-1.5.3.RELEASE(相对应的spring版本是spring-webmvc-4.3.8.RELEASE)

    • spring-boot-2.0.1.RELEASE(相对应的spring版本是spring-webmvc-5.0.5.RELEASE)

  • 关于配置类,在spring boot 2.x已经改为最低支持jdk8版本,而jdk8中的接口允许有默认实现,所以已经废弃掉WebMvcConfigurerAdapter适配类,而改为直接实现WebMvcConfigurer接口

  •  

 
posted @ 2019-03-22 11:56  tianlong88  阅读(1005)  评论(0编辑  收藏  举报