Spring3之 bean简单属性注入

DI （依赖注入）有二种： Constructor-based dependency injection and Setter-based dependency

a)、Constructor-based  DI

com.spring305.test.beanInit.po.InitSingeBean.java

import java.util.Date;

public class InitSingeBean {

	private int id;
	private Integer age;
	private String name;
	private Date birth;
	private Double weight;
	private float height;
	private Boolean sex;

	public InitSingeBean() {
		super();
		System.out.println(this);
	}

	public InitSingeBean(int id, Integer age) {
		super();
		this.id = id;
		this.age = age;
		System.out.println(this+"_"+id+"_"+age);
	}
	
	public InitSingeBean(int id, Integer age, String name, Date birth,
			Double weight, float height, Boolean sex) {
		super();
		this.id = id;
		this.age = age;
		this.name = name;
		this.birth = birth;
		this.weight = weight;
		this.height = height;
		this.sex = sex;
		System.out.println(this);
	}
	public InitSingeBean(int id, Integer age, String name, Double weight, float height, Boolean sex) {
		super();
		this.id = id;
		this.age = age;
		this.name = name;
		this.weight = weight;
		this.height = height;
		this.sex = sex;
		System.out.println(this);
	}

	public void test(){
		System.out.println(id+"_"+age+"_"+name+"_"+birth+"_"+weight+"_"+height+"_"+sex);
	}

.....getter settter
}

 Test.java
 

@Test
public void InitSingeBean() {
	//System.out.println(new Date());
	ApplicationContext context =  new ClassPathXmlApplicationContext("testBeanInit.xml");
	InitSingeBean initSingeBean = (InitSingeBean) context.getBean("initSingeBean");
	initSingeBean.test();
}

src/ testBeanInit.XML

 

<!-- 
		没有任何参数注入
	<bean id="initSingeBean" class="com.spring305.test.beanInit.po.InitSingeBean">
	</bean>
	 -->
	 
	 <!-- 
	 	构造参数注入，但是，要注意的是这个index(顺序)/type(类型)/value(值)的顺序，而且，这里是不支持自动装箱和拆箱的哦，int Integer,貌似不能自动转 
	 <bean id="initSingeBean" class="com.spring305.test.beanInit.po.InitSingeBean">
		<constructor-arg type="int" value="750"/>
		<constructor-arg type="Integer" value="057"/>
	</bean>
	-->
	
	<!--
	 构造参数注入2
	 <constructor-arg index="0" value="750"/>
	 <constructor-arg type="int" value="750"/>
	 2011-04-16 12:00:00  时间的注入不能写成这样子的，这种写法应该是中国cn区的写法吧。
	 包装类型的要写包装类型，加上包名也是可以的	
	 <bean id="initSingeBean" class="com.spring305.test.beanInit.po.InitSingeBean">
		<constructor-arg index="0"><value>750</value></constructor-arg>
		<constructor-arg type="java.lang.Integer" value="057"/>
		<constructor-arg type="String" value="00001测试"/>
		<constructor-arg type="java.util.Date" value="Sat Apr 16 15:20:13 CST 2011"/>
		<constructor-arg type="java.lang.Double" value="2011.0123"/>
		<constructor-arg type="float" value="2011.0321"/>
		<constructor-arg type="java.lang.Boolean" value="true"/>
	</bean>
	 -->

 

 b)、Setter-based  DI

XML

<!--
	  	setter设值注入
	 <bean id="dateBean" class="java.util.Date"/>
	 或者 <bean id="dateFormat" class="java.text.SimpleDateFormat">
		<constructor-arg value="yyyy-MM-dd" />
  	 </bean>
	 <ref bean="dateBean"/> 
	 or  <bean id="dateBean" class="java.util.Date"/> either is ok-->
	 <bean id="dateFormat" class="java.text.SimpleDateFormat">
		<constructor-arg value="yyyy-MM-dd" />
  	 </bean>
	 <bean id="initSingeBean" class="com.spring305.test.beanInit.po.InitSingeBean">
	 	<property name="id" value="23"></property>
	 	<property name="age" value="34"></property>
	 	<property name="name"><value>jdbc:mysql://localhost:3306/mydb</value></property>
	 	<property name="birth"> 
	 		<!-- <ref bean=dateBean/>  -->
	 		<bean factory-bean="dateFormat" factory-method="parse">
				<constructor-arg value="2010-01-31" />
			</bean>
	 	</property>
	 	<property name="weight" value="2011.0123"></property>
	 	<property name="height" value="23"></property>
	 	<property name="sex" value="false"></property>
	 </bean>

 <!-- 
   org.apache.commons.dbcp.BasicDataSource
   这个怎么样，不过你得先在XML头中加上 xmlns:p="http://www.springframework.org/schema/p"
  <bean id="initSingeBean" class="com.spring305.test.beanInit.po.InitSingeBean"
  p:id="123"
  p:age="345"
  p:name="dbc:mysql://localhost:3306/mydb"
  p:birth="Sat Apr 16 15:20:13 CST 2011"/>
  
  -->
  

 

到底使用哪种来注入？

Spring3官方文档：

<!--EndFragment-->

it is a good rule of thumb to use constructor arguments for mandatory dependencies and setters for optional dependencies。....The Spring team generally advocates setter injection

 关于一般属性的注解现没在文档上找到。。。估计那样也没多大意义。。。