1.使用spring后，被spring管理的类，不需要再new。
2.要想类被spring管理，则需要通过bean的方式，把类引入到spirng的配置文件中。
导入spring依赖
<properties>
<maven.compiler.source>8maven.compiler.source>
<maven.compiler.target>8maven.compiler.target>
<spring.version>4.0.1.RELEASEspring.version>
properties>
<dependencies>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-webmvcartifactId>
<version>${spring.version}version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-txartifactId>
<version>${spring.version}version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-jdbcartifactId>
<version>${spring.version}version>
dependency>
<dependency>
<groupId>org.aspectjgroupId>
<artifactId>aspectjweaverartifactId>
<version>1.9.2version>
dependency>
dependencies>
在资源目录下创建spring-config.xml。
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:p="http://www.springframework.org/schema/p"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.0.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd">
beans>
创建一个实体类User
// 省略了getset
public class User {
private int uid;
private String uname;
private String upassword;
}
注册bean
<bean id="zhangsan" class="com.pojo.User">
<property name="uname" value="张三"/>
<property name="upassword" value="123"/>
bean>
测试
public static void main(String[] args) {
ApplicationContext context = new ClassPathXmlApplicationContext("spring-config.xml");
User user = (User) context.getBean("zhangsan");
System.out.println(user.getUname());
}
AOP的理解：
1、创建增强类
package com.advice;
public class LoggerAdvice {
public void before(){
System.out.println("LoggerAdvice.before()");
}
}
2、创建要切入的业务类
package com.service;
public class UserService {
public void login() {
System.out.println("login");
}
}
3、注册到spring中和配置切面
<bean id="userService" class="com.service.UserService">bean>
<bean id="loggerAdvice" class="com.advice.LoggerAdvice"/>
<aop:config>
<aop:pointcut id="pointcut" expression="execution(* com.service.*.*(..))"/>
<aop:aspect ref="loggerAdvice">
<aop:before method="before" pointcut-ref="pointcut"/>
aop:aspect>
aop:config>
package com.printor;
public interface Ink {
public void show();
}
package com.printor;
public class InkColor implements Ink{
@Override
public void show() {
System.out.println("彩色");
}
}
package com.printor;
public interface Paper {
public void show();
}
package com.printor;
public class PaperA4 implements Paper{
@Override
public void show() {
System.out.println("A4纸");
}
}
package com.printor;
public class PaperB5 implements Paper{
@Override
public void show() {
System.out.println("B5");
}
}
package com.printor;
public class HPPrintor {
private Ink ink;
private Paper paper;
public void print(String content) {
System.out.println("HP打印机打印内容：" + content);
this.ink.show();
this.paper.show();
}
public Ink getInk() {
return ink;
}
public void setInk(Ink ink) {
this.ink = ink;
}
public Paper getPaper() {
return paper;
}
public void setPaper(Paper paper) {
this.paper = paper;
}
}
将以上的类，注册到spring中
<bean id="inkColor" class="com.printor.InkColor">bean>
<bean id="paperA4" class="com.printor.PaperA4">bean>
<bean id="paperB5" class="com.printor.PaperB5">bean>
<bean id="hpPrintor1" class="com.printor.HPPrintor">
<property name="ink" ref="inkColor"/>
<property name="paper" ref="paperA4"/>
bean>
<bean id="hpPrintor2" class="com.printor.HPPrintor">
<property name="ink" ref="inkColor"/>
<property name="paper" ref="paperB5"/>
bean>
通过注解实现
<context:component-scan base-package="com.printor">context:component-scan>
InkColor、PaperA4、PaperB5、HPPrintor类上增加@Component注解
@Component
public class HpPrintor {
@Autowired
private Ink ink;
@Autowired
@Qualifier("paperA4")
private Paper paper;
}
使用注解实现
<context:component-scan base-package="com.service">context:component-scan>
<aop:aspectj-autoproxy/>
package com.advice;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.*;
import org.springframework.stereotype.Component;
import java.util.Arrays;
@Aspect
@Component
public class PrintAdvice {
@Pointcut("execution(* com.service.*.*(..))")
public void pointcut(){
}
@Before("pointcut()")
public void before(JoinPoint joinPoint) {
System.out.println("打印前");
String target = joinPoint.getTarget().toString(); // 类
String method = joinPoint.getSignature().getName(); // 方法
String args = Arrays.toString(joinPoint.getArgs()); // 参数列表
System.out.println(target);
System.out.println(method);
System.out.println(args);
}
@After("pointcut()")
public void after() {
System.out.println("打印后");
}
@AfterReturning(pointcut = "pointcut()",returning = "ret")
public void afterReturning(JoinPoint joinPoint, Object ret) {
System.out.println("打印成功");
}
@AfterThrowing(pointcut = "pointcut()",throwing = "e")
public void afterThrowing(Exception e) {
System.out.println("打印失败");
}
@Around("pointcut()")
public Object around(ProceedingJoinPoint joinPoint) {
System.out.println("打印中");
Object result = null;
try {
// 执行目标方法
result = joinPoint.proceed();
// 返回通知逻辑
System.out.println("After method execution, result: " + result);
} catch (Exception e) {
// 异常通知逻辑
System.out.println("Exception occurred: " + e.getMessage());
} catch (Throwable e) {
e.printStackTrace();
} finally {
// 后置最终通知，无论是否发生异常都会执行
System.out.println("Finally block executed");
return result;
}
}
}