spring-2
1. Xml
<!-- \src\applicationContext-annotation.xml -->
<?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"
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-4.0.xsd">
<!-- 配置自动扫描的包 -->
<context:component-scan base-package="com.atguigu.spring.ref"></context:component-scan>
</beans>
<!-- \src\applicationContext-aop.xml -->
<?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:aop="http://www.springframework.org/schema/aop"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.0.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd">
<!-- 自动扫描的包 -->
<context:component-scan base-package="com.atguigu.spring.aop"></context:component-scan>
<!-- 使 AspectJ 的注解起作用 -->
<aop:aspectj-autoproxy></aop:aspectj-autoproxy>
</beans>
<!-- \src\applicationContext.xml -->
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
<!--
1. 默认情况下, IOC 容器中的 bean 是单例的! 若对象是单例的, 则在创建 IOC 容器时即创建 bean 的实例, 并对 bean 的属性进行初始化.
2. 可以通过 bean 的 scope 属性来修改 bean 的作用域. 若取值为 prototype, 则 bean 为原型的: 每次向容器获取实例, 得到的都是一个新的对象.
而且, 不在创建 IOC 容器时创建 bean 的实例了.
3. IOC 容器中 bean 的生命周期:
3.1 一般地, 讨论 bean 的生命周期, 是建立在 bean 是单例的基础上的.
3.2 可以为 bean 指定 init 和 destroy 方法
3.3 还可以通过 bean 的后置处理器来更加丰富 bean 的生命周期方法(面试时.).
-->
<bean id="helloWorld"
class="com.atguigu.spring.helloworld.HelloWorld"
scope="singleton"
init-method="init"
destroy-method="destroy">
<property name="userName" value="atguigu"></property>
</bean>
<!--
1. 在 IOC 容器中配置 bean 之间的关联关系
-->
<bean id="userDao"
class="com.atguigu.spring.ref.UserDao"></bean>
<bean id="userService"
class="com.atguigu.spring.ref.UserService">
<property name="userDao" ref="userDao"></property>
</bean>
<bean id="userAction"
class="com.atguigu.spring.ref.UserAction">
<property name="userService" ref="userService"></property>
</bean>
</beans>
2. Java
// \src\com\atguigu\spring\aop\ArithmeticCalculator.java
package com.atguigu.spring.aop;
public interface ArithmeticCalculator {
int add(int i, int j);
int sub(int i, int j);
int mul(int i, int j);
int div(int i, int j);
}
// \src\com\atguigu\spring\aop\ArithmeticCalculatorImpl.java
package com.atguigu.spring.aop;
import org.springframework.stereotype.Component;
@Component("arithmeticCalculator")
public class ArithmeticCalculatorImpl implements ArithmeticCalculator {
@Override
public int add(int i, int j) {
int result = i + j;
return result;
}
@Override
public int sub(int i, int j) {
int result = i - j;
return result;
}
@Override
public int mul(int i, int j) {
int result = i * j;
return result;
}
@Override
public int div(int i, int j) {
int result = i / j;
return result;
}
}
// \src\com\atguigu\spring\aop\ArithmeticCalculatorLoggingImpl.java
package com.atguigu.spring.aop;
public class ArithmeticCalculatorLoggingImpl implements ArithmeticCalculator {
@Override
public int add(int i, int j) {
System.out.println("The method add begins with [" + i + "," + j + "]");
int result = i + j;
System.out.println("The method add ends with " + result);
return result;
}
@Override
public int sub(int i, int j) {
System.out.println("The method sub begins with [" + i + "," + j + "]");
int result = i - j;
System.out.println("The method sub ends with " + result);
return result;
}
@Override
public int mul(int i, int j) {
System.out.println("The method mul begins with [" + i + "," + j + "]");
int result = i * j;
System.out.println("The method mul ends with " + result);
return result;
}
@Override
public int div(int i, int j) {
System.out.println("The method div begins with [" + i + "," + j + "]");
int result = i / j;
System.out.println("The method div ends with " + result);
return result;
}
}
// \src\com\atguigu\spring\aop\ArithmeticCalculatorLoggingProxy.java
package com.atguigu.spring.aop;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.util.Arrays;
public class ArithmeticCalculatorLoggingProxy {
//要代理的对象
private ArithmeticCalculator target;
public ArithmeticCalculatorLoggingProxy(ArithmeticCalculator target) {
super();
this.target = target;
}
//返回代理对象
public ArithmeticCalculator getLoggingProxy(){
ArithmeticCalculator proxy = null;
ClassLoader loader = target.getClass().getClassLoader();
Class [] interfaces = new Class[]{ArithmeticCalculator.class};
InvocationHandler h = new InvocationHandler() {
/**
* proxy: 代理对象。 一般不使用该对象
* method: 正在被调用的方法
* args: 调用方法传入的参数
*/
@Override
public Object invoke(Object proxy, Method method, Object[] args)
throws Throwable {
String methodName = method.getName();
//打印日志
System.out.println("[before] The method " + methodName + " begins with " + Arrays.asList(args));
//调用目标方法
Object result = null;
try {
//前置通知
result = method.invoke(target, args);
//返回通知, 可以访问到方法的返回值
} catch (NullPointerException e) {
e.printStackTrace();
//异常通知, 可以访问到方法出现的异常
}
//后置通知. 因为方法可以能会出异常, 所以访问不到方法的返回值
//打印日志
System.out.println("[after] The method ends with " + result);
return result;
}
};
/**
* loader: 代理对象使用的类加载器。
* interfaces: 指定代理对象的类型. 即代理代理对象中可以有哪些方法.
* h: 当具体调用代理对象的方法时, 应该如何进行响应, 实际上就是调用 InvocationHandler 的 invoke 方法
*/
proxy = (ArithmeticCalculator) Proxy.newProxyInstance(loader, interfaces, h);
return proxy;
}
}
// \src\com\atguigu\spring\aop\LoggingAspect.java
package com.atguigu.spring.aop;
import java.util.Arrays;
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.springframework.stereotype.Component;
/**
* AOP 的 helloWorld
* 1. 加入 jar 包
* com.springsource.net.sf.cglib-2.2.0.jar
* com.springsource.org.aopalliance-1.0.0.jar
* com.springsource.org.aspectj.weaver-1.6.8.RELEASE.jar
* spring-aspects-4.0.0.RELEASE.jar
*
* 2. 在 Spring 的配置文件中加入 aop 的命名空间。
*
* 3. 基于注解的方式来使用 AOP
* 3.1 在配置文件中配置自动扫描的包: <context:component-scan base-package="com.atguigu.spring.aop"></context:component-scan>
* 3.2 加入使 AspjectJ 注解起作用的配置: <aop:aspectj-autoproxy></aop:aspectj-autoproxy>
* 为匹配的类自动生成动态代理对象.
*
* 4. 编写切面类:
* 4.1 一个一般的 Java 类
* 4.2 在其中添加要额外实现的功能.
*
* 5. 配置切面
* 5.1 切面必须是 IOC 中的 bean: 实际添加了 @Component 注解
* 5.2 声明是一个切面: 添加 @Aspect
* 5.3 声明通知: 即额外加入功能对应的方法.
* 5.3.1 前置通知: @Before("execution(public int com.atguigu.spring.aop.ArithmeticCalculator.*(int, int))")
* @Before 表示在目标方法执行之前执行 @Before 标记的方法的方法体.
* @Before 里面的是切入点表达式:
*
* 6. 在通知中访问连接细节: 可以在通知方法中添加 JoinPoint 类型的参数, 从中可以访问到方法的签名和方法的参数.
*
* 7. @After 表示后置通知: 在方法执行之后执行的代码.
*/
//通过添加 @Aspect 注解声明一个 bean 是一个切面!
@Aspect
@Component
public class LoggingAspect {
@Before("execution(public int com.atguigu.spring.aop.ArithmeticCalculator.*(int, int))")
public void beforeMethod(JoinPoint joinPoint){
String methodName = joinPoint.getSignature().getName();
Object [] args = joinPoint.getArgs();
System.out.println("The method " + methodName + " begins with " + Arrays.asList(args));
}
@After("execution(* com.atguigu.spring.aop.*.*(..))")
public void afterMethod(JoinPoint joinPoint){
String methodName = joinPoint.getSignature().getName();
System.out.println("The method " + methodName + " ends");
}
}
// \src\com\atguigu\spring\aop\Main.java
package com.atguigu.spring.aop;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class Main {
public static void main(String[] args) {
// ArithmeticCalculator arithmeticCalculator = new ArithmeticCalculatorImpl();
//
// arithmeticCalculator =
// new ArithmeticCalculatorLoggingProxy(arithmeticCalculator).getLoggingProxy();
//
// int result = arithmeticCalculator.add(11, 12);
// System.out.println("result:" + result);
//
// result = arithmeticCalculator.div(21, 3);
// System.out.println("result:" + result);
ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext-aop.xml");
ArithmeticCalculator arithmeticCalculator = (ArithmeticCalculator) ctx.getBean("arithmeticCalculator");
System.out.println(arithmeticCalculator.getClass().getName());
int result = arithmeticCalculator.add(11, 12);
System.out.println("result:" + result);
result = arithmeticCalculator.div(21, 3);
System.out.println("result:" + result);
}
}
// \src\com\atguigu\spring\helloworld\HelloWorld.java
package com.atguigu.spring.helloworld;
public class HelloWorld {
//字段
private String user;
public HelloWorld() {
System.out.println("HelloWorld's constructor...");
}
//JavaBean 使用 setter 和 getter 来定义属性
public void setUserName(String user) {
System.out.println("setUserName:" + user);
this.user = user;
}
public void hello(){
System.out.println("Hello:" + user);
}
public void init(){
System.out.println("init method...");
}
public void destroy(){
System.out.println("destroy method...");
}
}
// \src\com\atguigu\spring\helloworld\Main.java
package com.atguigu.spring.helloworld;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class Main {
public static void main(String[] args) {
//1. 创建 IOC 容器
ClassPathXmlApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
//2. 从 IOC 容器中获取 bean 实例
HelloWorld helloWorld = (HelloWorld) ctx.getBean("helloWorld");
//3. 调用 bean 的方法
helloWorld.hello();
HelloWorld helloWorld2 = (HelloWorld) ctx.getBean("helloWorld");
System.out.println(helloWorld == helloWorld2);
//4. 关闭容器
ctx.close();
}
}
// \src\com\atguigu\spring\ref\Main.java
package com.atguigu.spring.ref;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class Main {
public static void main(String[] args) {
//1. 创建 IOC 容器
ClassPathXmlApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext-annotation.xml");
UserAction userAction = (UserAction) ctx.getBean("userAction");
userAction.execute();
}
}
// \src\com\atguigu\spring\ref\UserAction.java
package com.atguigu.spring.ref;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
@Controller
public class UserAction {
private UserService userService;
@Autowired
public void setUserService(UserService userService) {
this.userService = userService;
}
public void execute(){
System.out.println("execute...");
userService.addNew();
}
}
// \src\com\atguigu\spring\ref\UserDao.java
package com.atguigu.spring.ref;
import org.springframework.stereotype.Repository;
@Repository
public class UserDao {
public void save(){
System.out.println("UserDao's save...");
}
}
// \src\com\atguigu\spring\ref\UserService.java
package com.atguigu.spring.ref;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
@Service
public class UserService {
@Autowired
private UserDao userDao;
public void setUserDao(UserDao userDao) {
this.userDao = userDao;
}
public void addNew(){
System.out.println("addNew...");
userDao.save();
}
}
