一、拦截器简介
1、拦截器定义
拦截器，请求的接口被访问之前，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
请求数据校验
用户权限校验
放行指定接口
二、SpringBoot2.0拦截器用法
1、编写两个拦截器
自定义类实现HandlerInterceptor接口
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配置文件中注入拦截器
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配置文件
*/
@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、编写测试接口
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、访问测试接口
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配置文件中注入拦截器的顺序执行的。
三、源代码地址
GitHub地址：知了一笑
https://github.com/cicadasmile
码云地址：知了一笑
https://gitee.com/cicadasmile
![gzh20190804]( "gzh20190804")
