过滤器，拦截器，SpringAop执行顺序详解（基于Springboot2.0）
结论：能看懂就不用往下翻了，不过点个赞还是很nice的
====doFilter====
====preHandle====
=====around02 start====
====before02=====
=====around01 start====
====before01=====
====method run====
=====around01 end====1
=====after01====
=====afterReturning01====1
=====around02 end====2
=====after02====
=====afterReturning02====2
====postHandle====
====afterCompletion====1、Spring Aop
aop怎么声明就不用啰嗦了，注意：
通知声明类上加上：@Aspect @Component
单个通知类，上代码：
@Aspect
@Component
@Slf4j
public class TestAspect01 {
@Pointcut("execution(* com.springboot.netty.spingbootnetty.singleTon.UserService.*(..))")
public void flag() {
}
@Before("flag()")
public void before(JoinPoint joinPoint) {
System.out.println("====before01=====");
}
@After("flag()")
public void after(JoinPoint joinPoint) {
System.out.println("=====after01====");
}
@AfterReturning(value = "flag()", returning = "result")
public void afterReturning(JoinPoint joinPoint, Object result) {
System.out.println("=====afterReturning01====" + result);
}
@AfterThrowing(pointcut = "flag()", throwing = "e")
public void afterThrowing(JoinPoint joinPoint, Exception e) {
System.out.println("=====afterThrowing01====");
}
@Around("flag()")
public Object around(ProceedingJoinPoint joinPoint) throws Throwable {
System.out.println("=====around01 start====");
String result = null;
result = (String) joinPoint.proceed();
System.out.println("=====around01 end====" + result);
return result;
}
}单个通知类执行顺序，正常情况：result为被拦截方法的返回值，（返回通知想要取到返回值，前提是你必须在环绕通知中把result返回出去）
=====around01 start====
====before01=====
====method run====
=====around01 end====result=1
=====after01====
=====afterReturning01====result=1
单个通知类执行顺序，异常情况：
=====around01 start====
====before01=====
====method run====
=====after01====
=====afterThrowing01====
多个通知类，上代码：
注意加了@Order注解，数字越小执行越早
@Aspect
@Component
@Slf4j
@Order(1)
public class TestAspect02 {
@Pointcut("execution(* com.springboot.netty.spingbootnetty.singleTon.UserService.*(..))")
public void flag() {
}
@Before("flag()")
public void before(JoinPoint joinPoint) {
System.out.println("====before02=====");
}
@After("flag()")
public void after(JoinPoint joinPoint) {
System.out.println("=====after02====");
}
@AfterReturning(value = "flag()", returning = "result")
public void afterReturning(JoinPoint joinPoint, Object result) {
System.out.println("=====afterReturning02====" + result);
}
@AfterThrowing(value = "flag()")
public void afterThrowing(JoinPoint joinPoint) {
System.out.println("=====afterThrowing02====");
}
@Around("flag()")
public Object around(ProceedingJoinPoint joinPoint) throws Throwable {
System.out.println("=====around02 start====");
String result = null;
result = (String) joinPoint.proceed();
result = "2";
System.out.println("=====around02 end====" + result);
return result;
}
}单个通知类执行顺序，正常情况：
=====around02 start====
====before02=====
=====around01 start====
====before01=====
====method run====
=====around01 end====result=1
=====after01====
=====afterReturning01====result=1
=====around02 end====result=2
=====after02====
=====afterReturning02====result=2
单个通知类执行顺序，异常情况：
=====around02 start====
====before02=====
=====around01 start====
====before01=====
====method run====
=====after01====
=====afterThrowing01====
=====after02====
=====afterThrowing02====
总结：
spring AOP就是面向切面编程，什么是切面，看图：
这就是为什么先执行的通知类后执行完的原因了！！！
2、拦截器
注意一点：拦截器需要注册
注册拦截器：
@Configuration
public class InterceptorConfig implements WebMvcConfigurer {
@Autowired
private MyInteceptor myInteceptor;
@Override
public void addInterceptors(InterceptorRegistry registry) {
registry.addInterceptor(myInteceptor).addPathPatterns("/**");
}
}上代码：
@Component
public class MyInteceptor implements HandlerInterceptor{
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
System.out.println("====preHandle====");
return true;
}
@Override
public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
System.out.println("====postHandle====");
}
@Override
public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
System.out.println("====afterCompletion====");
}
}aop、拦截器执行顺序：
====preHandle====
=====around02 start====
====before02=====
====method run====
=====around02 end====2
=====after02====
=====afterReturning02====2
====postHandle====
====afterCompletion====
3、过滤器
没什么好说的，上代码：
@Component
@WebFilter(filterName = "testFilter", urlPatterns = "/**")
public class TestFilter implements Filter {
@Override
public void init(FilterConfig filterConfig) throws ServletException {
System.out.println("----------------------->过滤器被创建");
}
@Override
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
HttpServletRequest req = (HttpServletRequest) servletRequest;
String requestURI = req.getRequestURI();
System.out.println("====doFilter====：请求地址"+requestURI);
filterChain.doFilter(servletRequest, servletResponse);
}
@Override
public void destroy() {
System.out.println("----------------------->过滤器被销毁");
}
}aop、拦截器、过滤器执行顺序：
====doFilter====
====preHandle====
=====around02 start====
====before02=====
====method run====
=====around02 end====2
=====after02====
=====afterReturning02====2
====postHandle====
====afterCompletion====