spring开发_Annotation_注解

项目结构：

http://www.cnblogs.com/hongten/gallery/image/112614.html

/spring_1800_Annotation/src/com/b510/app/test/SpringTest.java

package com.b510.app.test;

import java.util.Arrays;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

/**
 * 测试类
 * 
 * @author Hongten
 * 
 */
public class SpringTest {
    public static void main(String[] args) {
        ApplicationContext act = new ClassPathXmlApplicationContext("beans.xml");
        System.out.println(Arrays.toString(act.getBeanDefinitionNames()));
    }
}

/spring_1800_Annotation/src/com/b510/service/AnimalService.java

package com.b510.service;


/**
 * 动物抽象类
 * 
 * @author Hongten
 * 
 */
public interface AnimalService {

    /**
     * 获取相关信息
*/
    public abstract void getInfo();

}

/spring_1800_Annotation/src/com/b510/service/MeatService.java

package com.b510.service;

/**
 * 定义抽象类MeatService肉类
 * 
 * @author Hongten
 * 
 */
public interface MeatService {

    /**
     * 定义方法whatMeat
     * 
     * @return 返回一个字符串
*/
    public abstract String whatMeat();
}

采用@Component和采用@Component("cat")有什么区别：

采用第一种方式添加注解，Spring会采用约定的方式来为这些Bean实例指定名称，这些Bean实例的名称默认是Bean类的首字母小写，其他部分不变。如：catServiceBean

而采用第二种方式添加注解，相当于覆盖了Spring提供的默认实例名称，所以Bean的实例名称为：cat

/spring_1800_Annotation/src/com/b510/service/impl/CatServiceBean.java

package com.b510.service.impl;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;

import org.springframework.stereotype.Component;

import com.b510.service.AnimalService;
import com.b510.service.MeatService;

/**
 * 定义猫类实现AnimaleService抽象类
 * 
 * @author Hongten
 * 
 */
@Component("cat")
public class CatServiceBean implements AnimalService {
    private int age;
    private MeatService meatService;

    public CatServiceBean(){
        System.out.println("猫类被初始化了");
    }

    public int getAge() {
        return age;
    }

    //指定出示化方法：@PostConstruct
    @PostConstruct
    @Override
    public void getInfo() {
        System.out.println("我是猫，我的年龄是:"+age+",我很喜欢吃"+meatService.whatMeat());
    }
    public MeatService getMeatService() {
        return meatService;
    }

    public void setAge(int age) {
        this.age = age;
    }
    @Resource(name="fish")
    public void setMeatService(MeatService meatService) {
        this.meatService = meatService;
    }
    

}

/spring_1800_Annotation/src/com/b510/service/impl/DogServiceBean.java

package com.b510.service.impl;

import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
import javax.annotation.Resource;

import org.springframework.stereotype.Component;

import com.b510.service.AnimalService;
import com.b510.service.MeatService;

/**
 * 定义DogServiceBean类
 * 
 * @author Hongten
 * 
 */
@Component("dog")
public class DogServiceBean implements AnimalService {
    private int age;
    // 修饰Field的时候，setter方法可以不要滴
    @Resource(name = "pork")
    private MeatService meatService;

    public DogServiceBean() {
        System.out.println("狗类被初始化了");
    }

    public int getAge() {
        return age;
    }

    // 指定的出示化方法
    @PostConstruct
    @Override
    public void getInfo() {
        System.out.println("我是狗，我的年龄是:" + age + ",我很喜欢吃"
                + meatService.whatMeat());
    }

    public MeatService getMeatService() {
        return meatService;
    }

    public void setAge(int age) {
        this.age = age;
    }

    // 指定Bean销毁之前的方法
    @PreDestroy
    public void close() {
        System.out.println("这是Bean DogServiceBean销毁之前的方法");
    }
}

/spring_1800_Annotation/src/com/b510/service/impl/FishServiceBean.java

package com.b510.service.impl;

import org.springframework.stereotype.Component;

import com.b510.service.MeatService;

/**
 * 定义鱼肉实现MeatService抽象类
 * 
 * @author Hongten
 * 
 */
@Component("fish")
public class FishServiceBean implements MeatService {

    public FishServiceBean(){
        System.out.println("鱼肉类被初始化了");
    }
    @Override
    public String whatMeat() {
        return "鱼肉";
    }

}

/spring_1800_Annotation/src/com/b510/service/impl/PorkServiceBean.java

package com.b510.service.impl;

import org.springframework.stereotype.Component;

import com.b510.service.MeatService;

/**
 * 定义猪肉实现MeatService抽象类
 * 
 * @author Hongten
 * 
 */
@Component("pork")
public class PorkServiceBean implements MeatService {

    public PorkServiceBean(){
        System.out.println("猪肉类被初始化了");
    }
    @Override
    public String whatMeat() {
        return "猪肉";
    }

}

/spring_1800_Annotation/src/beans.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"
    xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
    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
           http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.5.xsd
           http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd">
    <!-- 自动扫描指定包及其子包的所有Bean类 -->
    <context:component-scan base-package="com.b510.service"></context:component-scan>
    <bean id="cat" class="com.b510.service.impl.CatServiceBean">
        <property name="age" value="2"></property>
    </bean>
    <bean id="dog" class="com.b510.service.impl.DogServiceBean">
        <property name="age" value="5"></property>
    </bean>
</beans>

运行结果：

2012-3-12 21:17:39 org.springframework.context.support.AbstractApplicationContext prepareRefresh
信息: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@c1b531: display name [org.springframework.context.support.ClassPathXmlApplicationContext@c1b531]; startup date [Mon Mar 12 21:17:39 CST 2012]; root of context hierarchy
2012-3-12 21:17:39 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
信息: Loading XML bean definitions from class path resource [beans.xml]
2012-3-12 21:17:39 org.springframework.beans.factory.support.DefaultListableBeanFactory registerBeanDefinition
信息: Overriding bean definition for bean 'cat': replacing [Generic bean: class [com.b510.service.impl.CatServiceBean]; scope=singleton; abstract=false; lazyInit=false; autowireMode=0; dependencyCheck=0; autowireCandidate=true; primary=false; factoryBeanName=null; factoryMethodName=null; initMethodName=null; destroyMethodName=null; defined in file [D:\WordPlace\spring_workspace\spring_1800_Annotation\bin\com\b510\service\impl\CatServiceBean.class]] with [Generic bean: class [com.b510.service.impl.CatServiceBean]; scope=singleton; abstract=false; lazyInit=false; autowireMode=0; dependencyCheck=0; autowireCandidate=true; primary=false; factoryBeanName=null; factoryMethodName=null; initMethodName=null; destroyMethodName=null; defined in class path resource [beans.xml]]
2012-3-12 21:17:39 org.springframework.beans.factory.support.DefaultListableBeanFactory registerBeanDefinition
信息: Overriding bean definition for bean 'dog': replacing [Generic bean: class [com.b510.service.impl.DogServiceBean]; scope=singleton; abstract=false; lazyInit=false; autowireMode=0; dependencyCheck=0; autowireCandidate=true; primary=false; factoryBeanName=null; factoryMethodName=null; initMethodName=null; destroyMethodName=null; defined in file [D:\WordPlace\spring_workspace\spring_1800_Annotation\bin\com\b510\service\impl\DogServiceBean.class]] with [Generic bean: class [com.b510.service.impl.DogServiceBean]; scope=singleton; abstract=false; lazyInit=false; autowireMode=0; dependencyCheck=0; autowireCandidate=true; primary=false; factoryBeanName=null; factoryMethodName=null; initMethodName=null; destroyMethodName=null; defined in class path resource [beans.xml]]
2012-3-12 21:17:39 org.springframework.context.support.AbstractApplicationContext obtainFreshBeanFactory
信息: Bean factory for application context [org.springframework.context.support.ClassPathXmlApplicationContext@c1b531]: org.springframework.beans.factory.support.DefaultListableBeanFactory@587c94
2012-3-12 21:17:39 org.springframework.beans.factory.support.DefaultListableBeanFactory preInstantiateSingletons
信息: Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@587c94: defining beans [cat,dog,fish,pork,org.springframework.context.annotation.internalCommonAnnotationProcessor,org.springframework.context.annotation.internalAutowiredAnnotationProcessor,org.springframework.context.annotation.internalRequiredAnnotationProcessor]; root of factory hierarchy
猫类被初始化了
鱼肉类被初始化了
我是猫，我的年龄是:2,我很喜欢吃鱼肉
狗类被初始化了
猪肉类被初始化了
我是狗，我的年龄是:5,我很喜欢吃猪肉
[cat, dog, fish, pork, org.springframework.context.annotation.internalCommonAnnotationProcessor, org.springframework.context.annotation.internalAutowiredAnnotationProcessor, org.springframework.context.annotation.internalRequiredAnnotationProcessor]