SpringBoot添加自定义拦截器

在Controller层时，往往会需要校验或验证某些操作，而在每个Controller写重复代码，工作量比较大，这里在Springboot项目中 ，通过继承WebMvcConfigurerAdapter，添加拦截器。

1、WebMvcConfigurerAdapter源码

/*
 * Copyright 2002-2016 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.web.servlet.config.annotation;

import java.util.List;

import org.springframework.format.FormatterRegistry;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.validation.MessageCodesResolver;
import org.springframework.validation.Validator;
import org.springframework.web.method.support.HandlerMethodArgumentResolver;
import org.springframework.web.method.support.HandlerMethodReturnValueHandler;
import org.springframework.web.servlet.HandlerExceptionResolver;

/**
 * An implementation of {@link WebMvcConfigurer} with empty methods allowing
 * subclasses to override only the methods they're interested in.
 *
 * @author Rossen Stoyanchev
 * @since 3.1
 */
public abstract class WebMvcConfigurerAdapter implements WebMvcConfigurer {

    /**
     * {@inheritDoc}
     * <p>This implementation is empty.
     */
    @Override
    public void configurePathMatch(PathMatchConfigurer configurer) {
    }

    /**
     * {@inheritDoc}
     * <p>This implementation is empty.
     */
    @Override
    public void configureContentNegotiation(ContentNegotiationConfigurer configurer) {
    }

    /**
     * {@inheritDoc}
     * <p>This implementation is empty.
     */
    @Override
    public void configureAsyncSupport(AsyncSupportConfigurer configurer) {
    }

    /**
     * {@inheritDoc}
     * <p>This implementation is empty.
     */
    @Override
    public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
    }

    /**
     * {@inheritDoc}
     * <p>This implementation is empty.
     */
    @Override
    public void addFormatters(FormatterRegistry registry) {
    }

    /**
     * {@inheritDoc}
     * <p>This implementation is empty.
     */
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
    }

    /**
     * {@inheritDoc}
     * <p>This implementation is empty.
     */
    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
    }

    /**
     * {@inheritDoc}
     * <p>This implementation is empty.
     */
    @Override
    public void addCorsMappings(CorsRegistry registry) {
    }

    /**
     * {@inheritDoc}
     * <p>This implementation is empty.
     */
    @Override
    public void addViewControllers(ViewControllerRegistry registry) {
    }

    /**
     * {@inheritDoc}
     * <p>This implementation is empty.
     */
    @Override
    public void configureViewResolvers(ViewResolverRegistry registry) {
    }

    /**
     * {@inheritDoc}
     * <p>This implementation is empty.
     */
    @Override
    public void addArgumentResolvers(List<HandlerMethodArgumentResolver> argumentResolvers) {
    }

    /**
     * {@inheritDoc}
     * <p>This implementation is empty.
     */
    @Override
    public void addReturnValueHandlers(List<HandlerMethodReturnValueHandler> returnValueHandlers) {
    }

    /**
     * {@inheritDoc}
     * <p>This implementation is empty.
     */
    @Override
    public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
    }

    /**
     * {@inheritDoc}
     * <p>This implementation is empty.
     */
    @Override
    public void extendMessageConverters(List<HttpMessageConverter<?>> converters) {
    }

    /**
     * {@inheritDoc}
     * <p>This implementation is empty.
     */
    @Override
    public void configureHandlerExceptionResolvers(List<HandlerExceptionResolver> exceptionResolvers) {
    }

    /**
     * {@inheritDoc}
     * <p>This implementation is empty.
     */
    @Override
    public void extendHandlerExceptionResolvers(List<HandlerExceptionResolver> exceptionResolvers) {
    }

    /**
     * {@inheritDoc}
     * <p>This implementation returns {@code null}.
     */
    @Override
    public Validator getValidator() {
        return null;
    }

    /**
     * {@inheritDoc}
     * <p>This implementation returns {@code null}.
     */
    @Override
    public MessageCodesResolver getMessageCodesResolver() {
        return null;
    }

}

可以看出，该类 还能配置其他很多操作，例如异常处理，跨域请求等配置。

2、自动义Web配置类

import org.springframework.context.annotation.Bean;
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 WebMvcConfig extends WebMvcConfigurerAdapter {

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(getMyInterceptor()).addPathPatterns("/**");
    }
    
    @Bean
    public MyInterceptor getMyInterceptor(){
        return new MyInterceptor();
    }
    


}

　　如果需要添加多个拦截器，InterceptorRegistry registry.addInterceptor方法

public InterceptorRegistration addInterceptor(HandlerInterceptor interceptor) {
        InterceptorRegistration registration = new InterceptorRegistration(interceptor);
        this.registrations.add(registration);
        return registration;
    }

registrations是个数组结构，可以添加多个

3、自动义拦截器

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

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



public class MyInterceptor extends HandlerInterceptorAdapter {

    final Logger logger = LoggerFactory.getLogger(getClass());

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        //拦截操作
        return true;
    }
    
}