1.Introduce aop related dependencies
<!-- spring-aop dependency -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aop</artifactId>
<version>6.0.2</version>
</dependency>
<!-- spring aspects dependency-->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aspects</artifactId>
<version>6.0.2</version>
</dependency>
2. Create target resources
①Interface
public interface Calculator {
int add(int i,int j);
int sub(int i,int j);
int mul(int i,int j);
int div(int i,int j);
}
②Implementation class
@Component
public class CalculatorImpl implements Calculator {
@Override
public int add(int i, int j) {
int result = i + j;
System.out.println("method internal result = " + result);
return result;
}
@Override
public int sub(int i, int j) {
int result = i - j;
System.out.println("method internal result = " + result);
return result;
}
@Override
public int mul(int i, int j) {
int result = i * j;
System.out.println("method internal result = " + result);
return result;
}
@Override
public int div(int i, int j) {
int result = i / j;
System.out.println("method internal result = " + result);
return result;
}
}
3. Create aspect classes
//Aspect class
@Aspect//Aspect class
@Component//ioc container management
public class LogAspect {
}
Configuration bean file
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:aop="http://www.springframework.org/schema/aop"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop.xsd">
<!-- Turn on component scanning -->
<context:component-scan base-package="com.yogurt.spring6.aop.annoaop"></context:component-scan>
<!-- Turn on aspectj automatic proxy and generate a proxy for the target object -->
<aop:aspectj-autoproxy></aop:aspectj-autoproxy>
</beans>
①Entry point
pointcut expression
Example:
Pre-notification
@Aspect//Aspect class
@Component//ioc container management
public class LogAspect {
//Set entry point and notification type
//Pointcut expression: execution (access modifier, enhanced method return type, full path of the class where the enhanced method is located. Method name (method parameter))
//Notification type:
// Prefix @Before(value = "Pointcut expression configuration pointcut")
@Before(value = "execution(public int com.yogurt.spring6.aop.annoaop.CalculatorImpl.*(..))")
public void beforeMethod(){
System.out.println("Logger-->Pre-notification");
}
}
Post notification
// Post @After()
@After(value = "execution(* com.yogurt.spring6.aop.annoaop.CalculatorImpl.*(..))")
public void afterMethod(JoinPoint joinPoint){
String methodName = joinPoint.getSignature().getName();//Get the name of the enhanced method
System.out.println("Logger-->Post notification, method name: " + methodName);
}
Return notification
// Return @AfterReturning()
@AfterReturning(value = "execution(* com.yogurt.spring6.aop.annoaop.CalculatorImpl.*(..))",returning = "result")
public void afterReturningMethod(JoinPoint joinPoint,Object result){
String methodName = joinPoint.getSignature().getName();//Get the name of the enhanced method
System.out.println("Logger-->return notification, method name: " + methodName + ", return result: " + result);
}
Exception notification
//Exception @AfterThrowing() obtains the target method exception information
//An exception occurs in the target method, this notification is executed
@AfterThrowing(value = "execution(* com.yogurt.spring6.aop.annoaop.CalculatorImpl.*(..))",throwing = "ex")
public void afterThrowingMethod(JoinPoint joinPoint,Throwable ex){
String methodName = joinPoint.getSignature().getName();//Get the name of the enhanced method
System.out.println("Logger-->Exception notification, method name: " + methodName + ", exception information: " + ex);
}
At this time, the notification can only appear if the exception is set:
@Component
public class CalculatorImpl implements Calculator {
@Override
public int add(int i, int j) {
int result = i + j;
System.out.println("method internal result = " + result);
// //For testing purposes, simulate exceptions.
// int a = 1/0;
return result;
}
}
Surround notifications
// Surround @Around()
@Around(value = "execution(* com.yogurt.spring6.aop.annoaop.CalculatorImpl.*(..))")
public Object aroundMethod(ProceedingJoinPoint joinPoint){
String methodName = joinPoint.getSignature().getName();//Get the name of the enhanced method
Object[] args = joinPoint.getArgs();
String argString = Arrays.toString(args);
Object result = null;
try{
System.out.println("Surround notification == executed before target method");
//Call target method
result = joinPoint.proceed();
System.out.println("Surround notification == executed after the target method returns the value");
}catch (Throwable throwable){
throwable.printStackTrace();
System.out.println("Surround notification == abnormal execution of target method");
}finally {
System.out.println("Surround notification == target method execution completed");
}
return result;
}
②Notification type
Prefix @before()
Return @AfterReturning()
Exception @AfterThrowing()
Post @After()
Around @Around()
4. Test
public class TestAop {
@Test
public void testAdd(){
ApplicationContext context = new ClassPathXmlApplicationContext("bean.xml");
Calculator calculator = context.getBean(Calculator.class);
calculator.add(2,3);
}
}
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