一、拦截器简介

拦截器，请求的界面被访问之前，进行拦截然后在之前或之后加入某些操作。拦截是AOP的一种实现策略。 拦截器主要用来按照指定规则拒绝请求。

2、拦截器中应用

Token令牌验证

请求资料校验

使用者许可权校验

放行指定界面

二、SpringBoot2.0拦截器用法

自定义类实现HandlerInterceptor界面

1）OneInterceptor 拦截器

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

import org.springframework.web.servlet.HandlerInterceptor;

import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

/**

* 拦截器一

*/

public class OneInterceptor implements HandlerInterceptor {

private static final Logger LOGGER

= LoggerFactory.getLogger(OneInterceptor.class.getName());

@Override

public boolean preHandle(HttpServletRequest request,

HttpServletResponse response,

Object o) throws Exception {

String url =String.valueOf(request.getRequestURL()) ;

LOGGER.info("1、url=="+url);

// 放开拦截

return true;

}

@Override

public void postHandle(HttpServletRequest httpServletRequest,

HttpServletResponse httpServletResponse,

Object o, ModelAndView modelAndView) throws Exception {

LOGGER.info("1、postHandle");

}

@Override

public void afterCompletion(HttpServletRequest httpServletRequest,

HttpServletResponse httpServletResponse,

Object o, Exception e) throws Exception {

LOGGER.info("1、afterCompletion");

}

}

2）TwoInterceptor 拦截器

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

import org.springframework.web.servlet.HandlerInterceptor;

import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

/**

* 拦截器二

*/

public class TwoInterceptor implements HandlerInterceptor {

private static final Logger LOGGER

= LoggerFactory.getLogger(TwoInterceptor.class.getName());

@Override

public boolean preHandle(HttpServletRequest request,

HttpServletResponse response,

Object o) throws Exception {

String url =String.valueOf(request.getRequestURL()) ;

LOGGER.info("2、url=="+url);

// 放开拦截

return true;

}

@Override

public void postHandle(HttpServletRequest httpServletRequest,

HttpServletResponse httpServletResponse,

Object o, ModelAndView modelAndView) throws Exception {

LOGGER.info("2、postHandle");

}

@Override

public void afterCompletion(HttpServletRequest httpServletRequest,

HttpServletResponse httpServletResponse,

Object o, Exception e) throws Exception {

LOGGER.info("2、afterCompletion");

}

}

2、Web配置档案中注入拦截器

import com.boot.intercept.intercept.OneInterceptor;

import com.boot.intercept.intercept.TwoInterceptor;

import org.springframework.context.annotation.Configuration;

import org.springframework.web.servlet.config.annotation.InterceptorRegistry;

import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

/**

* Web配置档案

*/

@Configuration

public class WebMvcConfig implements WebMvcConfigurer {

public void addInterceptors(InterceptorRegistry registry) {

// 拦截所有路径

// 注册自定义两个拦截器

registry.addInterceptor(new OneInterceptor()).addPathPatterns("/**");

registry.addInterceptor(new TwoInterceptor()).addPathPatterns("/**");

}

}

3、编写测试界面

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RestController;

@RestController

public class InterceptController {

@RequestMapping("/reqUrl")

public String reqUrl (){

return "success" ;

}

}

4、访问测试界面

日志输出内容如下

intercept.OneInterceptor : 1、url==http://127.0.0.1:8005/reqUrl

intercept.TwoInterceptor : 2、url==http://127.0.0.1:8005/reqUrl

intercept.TwoInterceptor : 2、postHandle

intercept.OneInterceptor : 1、postHandle

intercept.TwoInterceptor : 2、afterCompletion

intercept.OneInterceptor : 1、afterCompletionla

拦截器的拦截顺序，是按照Web配置档案中注入拦截器的顺序执行的。

三、源代码地址

https://github.com/cicadasmile/spring-boot-base