Springboot實戰第五天：(1)spring的AOP應用-2019-8-21

 

關於spring的aop應用，其實用好了或者會用了對解決一些比較複雜的問題非常有幫助。

還是同樣上代碼：

在昨天的項目中新建一個包來實戰這個案例即可

1.添加 spring aop 支持及AspectJ 依賴

<!-- 添加 spring aop 支持及AspectJ 依賴  start -->
		<!--spring aop支持 -->
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-aop</artifactId>
			<version>4.1.6.RELEASE</version>
		</dependency>
		<!--aspectj支持 -->
		<dependency>
			<groupId>org.aspectj</groupId>
			<artifactId>aspectjrt</artifactId>
			<version>1.8.5</version>
		</dependency>
		<dependency>
			<groupId>org.aspectj</groupId>
			<artifactId>aspectjweaver</artifactId>
			<version>1.8.5</version>
		</dependency>
		<!-- 添加 spring aop 支持及AspectJ 依賴  end -->

2.編寫攔截規則的註解 

package com.amarsoft.springboot.aop;

import java.lang.annotation.Documented;
import java.lang.annotation.Target;
import java.lang.annotation.Retention;
import java.lang.annotation.ElementType;
import java.lang.annotation.RetentionPolicy;

@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface Action {
		String  name();
}

 

package com.amarsoft.springboot.aop;

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.EnableAspectJAutoProxy;

@Configuration
@ComponentScan("com.amarsoft.springboot.aop")
@EnableAspectJAutoProxy
public class AopConfig {

}

3.編寫使用註解的被攔截類 

package com.amarsoft.springboot.aop;

import org.springframework.stereotype.Service;

@Service
public class DemoAnnotationService {
	@Action(name=">>>註解式攔截的add操作")
	public  void add(){
	};
	
}

4.編寫使用方法規則被攔截類 

package com.amarsoft.springboot.aop;

import org.springframework.stereotype.Service;

@Service
public class DemoMethodService {
   public void add(){
	   System.out.println("-------Method方法規則式攔截------------");
   }
}

5.編寫切面 。注意配置切點表達式，我運行的時候有報錯，主要是

Pointcut is not well-formed: expecting 'name pattern' at character position

錯誤原因就在於通配符*要有空格

package com.amarsoft.springboot.aop;

import java.lang.reflect.Method;

import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;
import org.aspectj.lang.reflect.MethodSignature;
import org.springframework.stereotype.Component;
@Aspect
@Component
public class LogAspect {
	@Pointcut("@annotation(com.amarsoft.springboot.aop.Action)")
	public void annotationPointCut(){
	};
	@After("annotationPointCut()")
	public void after(JoinPoint  joinPoint){
		MethodSignature  signature=(MethodSignature) joinPoint.getSignature();
		Method method = signature.getMethod();
		Action action = method.getAnnotation(Action.class);
		System.out.println("註解式攔截"+action.name());
	}
	@Before("execution(* com.amarsoft.springboot.aop.DemoMethodService.add(..))")
	public void before(JoinPoint joinPoint){
		MethodSignature  signature=(MethodSignature) joinPoint.getSignature();
		Method method = signature.getMethod();
		System.out.println("方法規則攔截"+method.getName());
	}
}

 

6.配置類。這個類的作用就是@EnableAspectJAutoProxy開啓spring對AspectJ的支持

package com.amarsoft.springboot.aop;

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.EnableAspectJAutoProxy;

@Configuration
@ComponentScan("com.amarsoft.springboot.aop")
@EnableAspectJAutoProxy
public class AopConfig {

}

7.測試入口類 

package com.amarsoft.springboot.aop;

import org.springframework.context.annotation.AnnotationConfigApplicationContext;

public class AopApplication {
	public static void main(String[] args) {
		AnnotationConfigApplicationContext context=new AnnotationConfigApplicationContext(AopConfig.class);
		DemoAnnotationService demoAnnotationService =context.getBean(DemoAnnotationService.class);
		DemoMethodService demoMethodervice= context.getBean(DemoMethodService.class);
		demoAnnotationService.add();
		demoMethodervice.add();
		context.close();
		
	}
}

 

運行結果截圖：

這只是一個簡單的AOP的例子，以後大家要打印日誌，或者權限校驗，或者其他的一些操作，具有共性的都可以參考這種方式老開發。