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文章目录
过滤器 Filter（javaee提供）
定义时间拦截器
/**
* @Package com.whale.web.filter
* @Description: 时间拦截器
* @date 2019/2/11 13:18
*/
@Component//使拦截器生效
public class TimeFilter implements Filter {
@Override
public void init(FilterConfig filterConfig) throws ServletException {
System.out.println("TimeFilter init");
}
@Override
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
System.out.println("TimeFilter start");
long start = new Date().getTime();
filterChain.doFilter(servletRequest,servletResponse);
long end = new Date().getTime();
System.out.println("TimeFilter耗时(毫秒) : " +(end-start));
System.out.println("TimeFilter finish");
}
@Override
public void destroy() {
System.out.println("TimeFilter destroy");
}
}
请求方法
/**
* @param idxx
* @return
*/
@GetMapping("{id:\\d++}")
@JsonView(User.UserSimpleView.class)
public User getInfo4( @PathVariable(name = "id") String idxx){
System.out.println("=================");
//throw new UserNotExistException(idxx);
//System.out.println(idxx);
System.out.println("进入getInfo服务");
User u = new User();
u.setUsername("tom");
return u;
}
运行测试
拦截器在运行的时候就已经初始化
访问 http://127.0.0.1:8080/user/1
控制台如下
第三方拦截器的使用
以前我们使用拦截器时只需要在web.xml里面定义好
在spring boot 中需要再拦截器上加@Component注解
那如何使用第三方注解呢(不能使用注解了)
- 注释掉TimeFilter的@Component注解
- 创建配置类
@Configuration
public class WebConfig implements Serializable {
@Bean
public FilterRegistrationBean timeFilter(){
FilterRegistrationBean registrationBean = new FilterRegistrationBean();
TimeFilter timeFilter = new TimeFilter();
registrationBean.setFilter(timeFilter);
//设置过滤路径
List<String> urls = new ArrayList<>();
urls.add("/*");
registrationBean.setUrlPatterns(urls);
return registrationBean;
}
}
- 测试ok
拦截器 Interceptor(spring 框架本身提供)
自定义拦截器
@Component
public class TimeInterceptor implements HandlerInterceptor {
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
System.out.println("preHandle");
request.setAttribute("startTime",new Date().getTime());
return true;
}
@Override
public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler,ModelAndView modelAndView) throws Exception {
System.out.println("postHandle");
Long startTime = (Long) request.getAttribute("startTime");
System.out.println("time interceptor 耗时："+(new Date().getTime()-startTime));
}
@Override
public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler,Exception ex) throws Exception {
System.out.println("afterCompletion");
Long startTime = (Long) request.getAttribute("startTime");
System.out.println("time interceptor 耗时："+(new Date().getTime()-startTime));
System.out.println("ex is" +ex);
}
}
配置拦截器
@SuppressWarnings("deprecation")
@Configuration
public class WebConfig extends WebMvcConfigurerAdapter {
@Autowired
private TimeInterceptor timeInterceptor;
@Override
public void addInterceptors(InterceptorRegistry registry) {
registry.addInterceptor(timeInterceptor);
}
}
测试1
/**
* @param idxx
* @return
*/
@GetMapping("{id:\\d++}")
@JsonView(User.UserSimpleView.class)
public User getInfo4( @PathVariable(name = "id") String idxx){
System.out.println("=================");
//throw new UserNotExistException(idxx);
//System.out.println(idxx);
System.out.println("进入getInfo服务");
User u = new User();
u.setUsername("tom");
return u;
}
访问 http://127.0.0.1:8080/user/1
测试2 服务抛出异常
/**
* @param idxx
* @return
*/
@GetMapping("{id:\\d++}")
@JsonView(User.UserSimpleView.class)
public User getInfo4( @PathVariable(name = "id") String idxx){
System.out.println("=================");
throw new UserNotExistException(idxx);
//System.out.println(idxx);
//System.out.println("进入getInfo服务");
//User u = new User();
//u.setUsername("tom");
//return u;
}
500错误
{"messsage":"user not exists ! ","id":"1"}
控制台
这次没有打印出postHandle，ex 仍然为空
这是因为异常UserNotExistException被 controller异常处理器吞掉了
测试三 服务抛出运行时异常
/**
* @param idxx
* @return
*/
@GetMapping("{id:\\d++}")
@JsonView(User.UserSimpleView.class)
public User getInfo4( @PathVariable(name = "id") String idxx){
System.out.println("=================");
//throw new UserNotExistException(idxx);
throw new RuntimeException("user is not exists");
//System.out.println(idxx);
//System.out.println("进入getInfo服务");
//User u = new User();
//u.setUsername("tom");
//return u;
}
拦截器会拦截所有控制器
切片 Aspect
拦截器不能拿到拦截方法参数中的值
如果需要知道拦截方法中的参数，就需要切片
aop介绍
加入aop依赖
<!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-aop -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-aop</artifactId>
<!--<version>2.1.2.RELEASE</version>-->
</dependency>
自定义切片
@Aspect
@Component
public class TimeAspect{
//@Before() 相当于 拦截器的 preHandle
//@After()
//@AfterThrowing 抛出异常时调用
//@Around() 切入点 覆盖了上面三种 我们一般用这个
//第一个* 可以是任何返回值
//第二个* 类中的任何一个方法
//(..) 方法中的任意参数
//参考aop表达式语法
// https://docs.spring.io/spring/docs/4.3.22.RELEASE/spring-framework-reference/htmlsingle/#aop-pointcuts-examples
@Around("execution(* com.whale.web.controller.UserController.*(..))")
public Object handleControllerMethod(ProceedingJoinPoint pjp) throws Throwable {
System.out.println("time aspect start ");
Object[] args = pjp.getArgs();
for (Object arg : args) {
System.out.println("arg is " + arg);
}
long start = new Date().getTime();
Object object = pjp.proceed(); //切入点方法的返回值
System.out.println("time aspect 耗时： "+ (new Date().getTime()-start));
System.out.println("time aspect end ");
return object;
}
}
测试
/**
* @param idxx
* @return
*/
@GetMapping("{id:\\d++}")
@JsonView(User.UserSimpleView.class)
public User getInfo4( @PathVariable(name = "id") String idxx){
System.out.println("=================");
//throw new UserNotExistException(idxx);
//throw new RuntimeException("user is not exists");
System.out.println(idxx);
System.out.println("进入getInfo服务");
User u = new User();
u.setUsername("tom");
return u;
}
访问 http://127.0.0.1:8080/user/1
控制台如下
总结
