spring框架现在用的是如火如荼
管理bean的功能想必是大多数用户用途最广的一个功能
而依赖注入用途也是非常广泛
不知道从什么版本开始注解功能让开发变得很简单,也很简洁
本小例子,就是用注解的方式实现bean管理和依赖注入
小米2手机快要面市了,人人都想要,本例就以此为情境。
1.手机接口---不用多说,为了减少耦合性
package com.ioc.inerface;
public interface ITelphone {
public void call();
}
2.小米实现
package com.ioc.impl;
import org.springframework.stereotype.Component;
import com.ioc.inerface.ITelphone;
@Component("telphone")
public class TelphoneImpl implements ITelphone{
public String toString(){
return "我是手机(小米2)";
}
@Override
public void call() {
System.out.println("bing~~~喂,小米1,我是米2");
}
}
3.手机开发出来,得有电话本,姑且认为是一个单独类(不是手机的组件),电话本,不需要接口,耦合度不需要考虑
package com.ioc.impl;
import java.util.HashMap;
import java.util.Map;
import org.springframework.stereotype.Component;
@Component("addressBook")
public class AddressBook {
private Map mapBook = null;
private void init(){
mapBook = new HashMap();
mapBook.put("小米1", "0001");
}
public String getNum(String name){
if(mapBook == null){
init();
}
return (String) mapBook.get(name);
}
}
4.ok,手机开发好了,电话本也开发好了,人类出场,毕竟造这些东西都是给人类用,人类接口
package com.ioc.inerface;
public interface IPerson {
public void call();
}
5.人类实现:
package com.ioc.impl;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import com.ioc.inerface.IPerson;
import com.ioc.inerface.ITelphone;
import com.ioc.util.BeanFactory;
@Component("person")
public class PersonImpl implements IPerson{
@Autowired
private AddressBook addressBook;
public String toString(){
return "i am a human";
}
@Override
public void call() {
ITelphone telPhone = (ITelphone) BeanFactory.getBean("telphone");
String xm1Num = addressBook.getNum("小米1");
System.out.println("---开始打电话,电话号码:"+xm1Num);
telPhone.call();
System.out.println("---打电话结束");
}
}
6.可是spring管理容器还没造好呢,难道要用的时候再造么,那不太晚了
package com.ioc.util;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class BeanFactory {
private static ClassPathXmlApplicationContext ctx ;
static{
ctx = new ClassPathXmlApplicationContext("bean.xml");
}
public static Object getBean(String beanName){
return ctx.getBean(beanName);
}
public static void closeBeanFactory(){
ctx.destroy();
}
}
7.嗯,配置文件还没加上
<?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-2.5.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-2.5.xsd">
<!-- 扫描com.ioc下的所有类,自动为spring容器管理 -->
<context:component-scan base-package="com.ioc"/>
</beans>
8.ok,我们来测试吧
package com.ioc.test;
import com.ioc.inerface.IPerson;
import com.ioc.util.BeanFactory;
public class SpringIocTest {
public static void main(String[] args) {
IPerson perSon = (IPerson) BeanFactory.getBean("person");
perSon.call();
BeanFactory.closeBeanFactory();
}
}
运行结果:
---开始打电话,电话号码:0001
bing~~~喂,小米1,我是米2
---打电话结束
大功告成---其实在大多数运用中,这些知识就足够,简洁,易用,至于更详细的知识,需要进一步学习了。欢迎点评。
附:
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需要的jar
1.aspectjrt.jar
2.aspectjweaver.jar
3.cglib-nodep-2.1_3.jar
4.common-annotations.jar
5.commons-logging.jar
6.log4j-1.2.15.jar
7.spring.jar
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