Sping in Action读书笔记之一----------Bean的各种注入操作

Spring in Action这本书可以说是非常好的一本讲解Spring框架的好书，现在出版了第三版，包含了Spring3.0的许多

新特性，特此拿来好好系统的学习一番，以前对Spring有所了解，但是不是非常的详细，现在打算好好的认真的研究一

下Spring，先从最基础的开始吧。

1.Declaring a simple bean

这里声明了一个非常简单的Bean然后使用Spring的依赖注入技术实现对他的调用。

package com.bird.springidol;

/**
 * declaring a simple bean
 * @author Bird
 *
 */
public class Juggler {
	private int beanBags = 3;
	
	public Juggler(){
	}
	
	public Juggler(int beanBags){
		this.beanBags=beanBags;
	}
	
	public void perform(){
		System.out.println("Juggling "+beanBags+" BEANBAGS");
	}
}

只需要在XML文件中做如下配置

<?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-3.0.xsd" >

  <bean id="duke" class="com.bird.springidol.Juggler"></bean>

然后使用Junti测试框架进行测试

/**
	 * declaring a simple bean
	 */
	@Test
	public void test1(){
		ApplicationContext ctx = new ClassPathXmlApplicationContext("beans.xml");
		Juggler ju = (Juggler) ctx.getBean("duke");
		ju.perform();
	}

2.injecting through constructors

通过构造函数传入参数的注入方式

还是刚才的那个代码，这里使用了不同的配置方式

<bean id="duke1" class="com.bird.springidol.Juggler">
  	<constructor-arg value="15"></constructor-arg>
  </bean>

测试代码如下

/**
	 * Injecting through constructors
	 */
	@Test
	public void test2(){
		ApplicationContext ctx = new ClassPathXmlApplicationContext("beans.xml");
		Juggler ju = (Juggler) ctx.getBean("duke1");
		ju.perform();
	}
	

3.injecting object references with constructors

通过构造函数传入对象

package com.bird.springidol;

/**
 * injecting object references with constructors
 * @author Administrator
 *
 */
public class Poeticjuggler extends Juggler {
	private Poem poem;//倚赖注入的
	
	public Poeticjuggler(Poem poem){
		super();
		this.poem=poem;
	}
	
	public Poeticjuggler(int beanBags, Poem poem){
		super(beanBags);
		this.poem=poem;
	}
	
	public void perform(){
		super.perform();
		System.out.println("whing reciting.....");
		poem.recite();
	}
}

package com.bird.springidol;

public class Sonnect29 implements Poem {

	@Override
	public void recite() {
		System.out.println("this is a poem that too long");
	}

}

配置方式如下

<bean id="sonnet29" class="com.bird.springidol.Sonnect29"></bean>
   
   <bean id="poeticDuke" class="com.bird.springidol.Poeticjuggler">
   	<constructor-arg value="15"></constructor-arg>
   	<constructor-arg ref="sonnet29"></constructor-arg>
   </bean>

4.creating beans through factory methods

很多类使用单例设计模式，这样的对象只能通过静态方法生成一个对象，这里说一下如何注入这些对象

package com.bird.springidol;

/**
 * creating beans through factory methods
 * @author Administrator
 *
 */
public class Staage {
	private Staage(){}
	
	private static class StageSingletonHolder{
		static Staage instance = new Staage();
	}
	
	public static Staage getInstance(){
		return StageSingletonHolder.instance;
	}
}

 <bean id="theStage" class="com.bird.springidol.Staage" factory-method="getInstance"></bean>

5.initializing and destorying beans

在创建和删除Bean的时候调用的代码

只需要这样配置

<bean id="test1" class="" init-method="" destroy-method=""></bean>

6.injecting into bean properties

注入对象的属性

package com.bird.springidol;

/**
 * injecting into bean properties
 * 
 * @author Administrator
 * 
 */
public class Instrumentalist {
	private String song;
	private Instrument instrument;

	public String getSong() {
		return song;
	}

	public void setSong(String song) {
		this.song = song;
	}

	public Instrument getInstrument() {
		return instrument;
	}

	public void setInstrument(Instrument instrument) {
		this.instrument = instrument;
	}

	public Instrumentalist(){}
	
	public void perform(){
		System.out.println("playing"+song+":");
		instrument.play();
	}
}

package com.bird.springidol;

public class Saxophone implements Instrument {
	public Saxophone(){}
	@Override
	public void play() {
		System.out.println("TOOT TOOT TOOT");
	}

}

配置如下

 <bean id="saxophone" class="com.bird.springidol.Saxophone"></bean>
   <bean id="kenny" class="com.bird.springidol.Instrumentalist">
   		<property name="song" value="Jingle Bells"></property>
   		<property name="instrument" ref="saxophone"></property>
   </bean>