一，filter/interceptor/aop生效的先后顺序？
1,filter即过滤器，基于servlet容器，处于最外层，
所以它会最先起作用，最后才停止
说明：filter对所有访问到servlet容器的url都有效，包括静态资源
2,interceptor即拦截器,基于web框架,它会在filter之后起作用
说明：spring boot 1.x中，静态资源已被interceptor排除,
spring boot 2.x中，需要自己手动排除到静态资源的访问
filter和interceptor都是作用于请求
3,aop即切面，基于Spring的IOC容器,对spring管理的bean有效，
它会在interceptor之后才生效
aop可以作用于类和方法
如图:
说明：刘宏缔的架构森林是一个专注架构的博客，地址：https://www.cnblogs.com/architectforest
对应的源码可以访问这里获取： https://github.com/liuhongdi/
说明：作者:刘宏缔 邮箱: [email protected]
二，演示项目的相关信息
1,项目地址:
https://github.com/liuhongdi/costtime
2,项目的原理：
项目中使用了两个filter,两个interceptor,两个aspect,
功能分别都是：计算请求或方法执行的时间, 打印请求的参数
然后观察它们被执行到的顺序
3,项目结构：如图:
三，配置文件说明 :
pom.xml
<!--aop begin-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-aop</artifactId>
</dependency>
用来引入aop
四，java代码说明
1,DefaultMvcConfig.java
@Configuration
@ConditionalOnWebApplication(type = ConditionalOnWebApplication.Type.SERVLET)
public class DefaultMvcConfig implements WebMvcConfigurer {
@Resource
private LogInterceptor logInterceptor;
@Resource
private CostTimeInterceptor costTimeInterceptor; @Override
public void addViewControllers(ViewControllerRegistry registry) {
registry.addViewController("/").setViewName("/home/home");
} //添加Interceptor
@Override
public void addInterceptors(InterceptorRegistry registry) {
//1.加入的顺序就是拦截器执行的顺序，
//2.按顺序执行所有拦截器的preHandle
//3.所有的preHandle 执行完再执行全部postHandle 最后是postHandle
registry.addInterceptor(costTimeInterceptor)
.addPathPatterns("/home/home**")
.excludePathPatterns("/html/*","/js/*");
registry.addInterceptor(logInterceptor)
.addPathPatterns("/**")
.excludePathPatterns("/html/*","/static/**","/images/**");
} //add filter
@Bean
public FilterRegistrationBean addTimeFilterBean() {
FilterRegistrationBean registration = new FilterRegistrationBean();
registration.setFilter(new TimeFilter());
registration.setName("timeFilter");
registration.setOrder(2); //请求中过滤器执行的先后顺序，值越小越先执行
registration.addUrlPatterns("/home/*","/abc/*");
return registration;
} @Bean
public FilterRegistrationBean addLogFilterBean() {
FilterRegistrationBean registration = new FilterRegistrationBean();
registration.setFilter(new LogFilter());
registration.setName("logFilter");
registration.setOrder(1); //请求中过滤器执行的先后顺序，值越小越先执行
registration.addUrlPatterns("/*");
registration.addInitParameter("exclusions","/js/*,/images/*,*.js,*.gif,*.jpg,*.png,*.css,*.ico,/druid2/*");
return registration;
}
}
说明：拦截器是按加入到registry的顺序执行
filter是按setOrder中指定的顺序执行
另外：filter也可以用Order注解来指定顺序
2,CostTimeAspect.java
@Component
@Aspect
@Order(3)
public class CostTimeAspect {
ThreadLocal<Long> startTime = new ThreadLocal<>();
@Pointcut("execution(public * com.costtime.demo.controller.*.*(..))")
private void pointcut() {} //用around得到方法使用的时间
@Around(value = "pointcut()")
public Object doAround(ProceedingJoinPoint joinPoint) throws Throwable {
System.out.println("------costtime aop around begin");
long begin = System.nanoTime();
Object obj=joinPoint.proceed();
long end =System.nanoTime();
long timeMicro = (end-begin)/1000;
System.out.println("costtime aop 方法around:微秒数:"+timeMicro);
System.out.println("------costtime aop around end");
return obj;
} @Before("pointcut()")
public void doBefore(JoinPoint joinPoint) throws Throwable{
System.out.println("------costtime aop doBefore begin");
startTime.set(System.currentTimeMillis());
} //和doBefore搭配，得到使用的时间
@AfterReturning(returning = "ret" , pointcut = "pointcut()")
public void doAfterReturning(Object ret){
System.out.println("------costtime aop doAfterReturning begin");
System.out.println("costtime aop 方法doafterreturning:毫秒数:"+ (System.currentTimeMillis() - startTime.get()));
}
}
3,LogAspect.java
@Component
@Aspect
@Order(1)
public class LogAspect {
@Pointcut("execution(public * com.costtime.demo.controller.*.*(..))")
private void pointcut() {} @Around(value = "pointcut()")
public Object doAround(ProceedingJoinPoint joinPoint) throws Throwable {
System.out.println("------log aop around begin");
Object obj=joinPoint.proceed();
System.out.println("------log aop around end");
return obj;
} //把请求参数打印出来
@Before("pointcut()")
public void doBefore(JoinPoint joinPoint) throws Throwable{
System.out.println("------log aop doBefore begin");
ServletRequestAttributes attributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
HttpServletRequest request = attributes.getRequest(); //得到方法的参数名和参数值
Signature signature = joinPoint.getSignature();
MethodSignature methodSignature = (MethodSignature)signature;
String[] paramNames = methodSignature.getParameterNames();
Object[] args = joinPoint.getArgs();
String paramValue = "";
Map<String, Object> nameAndArgs = new HashMap<String, Object>();
for (int i = 0; i < paramNames.length; i++) {
paramValue+="parameter:"+paramNames[i]+";value:"+args[i];
} // 记录下请求内容
System.out.println("log aop URL : " + request.getRequestURL().toString());
System.out.println("log aop PARAM : " + request.getQueryString());
System.out.println("log aop HTTP_METHOD : " + request.getMethod());
System.out.println("log aop IP : " + request.getRemoteAddr());
System.out.println("log aop METHOD CLASS : " + joinPoint.getSignature().getDeclaringTypeName() );
System.out.println("log aop METHOD NAME: " + joinPoint.getSignature().getName());
System.out.println("log aop METHOD ARGS : " + paramValue);
} @AfterReturning(returning = "ret" , pointcut = "pointcut()")
public void doAfterReturning(Object ret){
System.out.println("------log aop doAfterReturning begin");
}
}
说明：这两个aspect用Order注解来指定执行的先后顺序，
值越小执行顺序越靠前
4,过滤器和拦截器的代码因为功能基本一致，为节省篇幅，不再贴出，
大家可以从github上访问:
https://github.com/liuhongdi/costtime
五，测试启动顺序的效果
1,访问url:
http://127.0.0.1:8080/home/home?v=1
查看控制台的输出:
----------------log filter doFilter begin
===执行过滤器功能
log filter URL : http://127.0.0.1:8080/home/home
log filter PARAM : v=1
log filter HTTP_METHOD : GET
log filter IP : 127.0.0.1
----------------time filter doFilter begin---------------time interceptor preHandle
[interceptor] request parameters: name:v;value:1
---------------log interceptor preHandle
[interceptor] request parameters: name:v;value:1------log aop around begin
------log aop doBefore begin
log aop URL : http://127.0.0.1:8080/home/home
log aop PARAM : v=1
log aop HTTP_METHOD : GET
log aop IP : 127.0.0.1
log aop METHOD CLASS : com.costtime.demo.controller.HomeController
log aop METHOD NAME: homeMethod
log aop METHOD ARGS : parameter:version;value:1
------costtime aop around begin
------costtime aop doBefore begin
------costtime aop doAfterReturning begin
costtime aop 方法doafterreturning:毫秒数:1027
costtime aop 方法around:微秒数:1027548
------costtime aop around end
------log aop doAfterReturning begin
------log aop around end
---------------log interceptor postHandle
---------------time interceptor postHandle
time interceptor 方法 postHandle:毫秒数:1108
---------------log interceptor afterCompletion
---------------time interceptor afterCompletion
timefilter: /home/home costtime: 1128ms
----------------time filter doFilter end
----------------log filter doFilter end
2,可以看到:
大类的启动顺序是:
filter
interceptor
aop
3，可以看到
filter的启动顺序，是按我们在config中设定的order顺序
interceptor的启动顺序，是addInterceptor到registry的顺序
同一个interceptor内部：执行顺序是: preHandle,postHandle,afterCompletion
aop的启动顺序：是我们在Order注解中指定的顺序
同一个aop内部：around比dobefore启动更早
六，查看spring boot的版本
. ____ _ __ _ _
/\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
\\/ ___)| |_)| | | | | || (_| | ) ) ) )
' |____| .__|_| |_|_| |_\__, | / / / /
=========|_|==============|___/=/_/_/_/
:: Spring Boot :: (v2.3.1.RELEASE)