spring 的集中注入方式

出自：http://www.blogjava.net/jiadong/archive/2007/08/29/140962.html

spring的三种注入方式：

---

1. 接口注入（不推荐）
2. getter，setter方式注入（比较常用）
3. 构造器注入（死的应用）

---

关于getter和setter方式的注入：

• autowire="defualt"
• autowire=“byName”
• autowire="bytype"

例如：有如下两个类需要注入

1packageorg.jia;
2
3publicclassOrder{
4privateStringorderNum;
5@SuppressWarnings("unused")
6privateOrderItemorderitem;
7
8publicOrderItemgetOrderitem(){
9returnorderitem;
10}
11
12publicvoidsetOrderitem(OrderItemorderitem){
13this.orderitem=orderitem;
14}
15
16publicStringgetOrderNum(){
17returnorderNum;
18}
19
20publicvoidsetOrderNum(StringorderNum){
21this.orderNum=orderNum;
22}
23
24}
25packageorg.jia;
26
27publicclassOrderItem{
28privateStringorderdec;
29
30publicStringgetOrderdec(){
31returnorderdec;
32}
33
34publicvoidsetOrderdec(Stringorderdec){
35this.orderdec=orderdec;
36}
37}
38

getter&&setter方式第一种注入：

<?xmlversion="1.0"encoding="UTF-8"?>
<!DOCTYPEbeansPUBLIC"-//SPRING//DTDBEAN//EN""http://www.springframework.org/dtd/spring-beans.dtd">

<beans>
<beanid="orderItem"class="org.jia.OrderItem">
<propertyname="orderdec"value="item00001"></property>
</bean>
<beanid="order"class="org.jia.Order">
<!-----注入变量 名字必须与类中的名字一样------->
<propertyname="orderNum"value="order000007"></property>
<！--注入对象 名字为orderitem，所属的类的应用id为orderItem-->
<propertyname="orderitem"ref="orderItem"></property>

--></bean>


</beans>

getter&&setter方式第二种注入： byName

<?xmlversion="1.0"encoding="UTF-8"?>
<!DOCTYPEbeansPUBLIC"-//SPRING//DTDBEAN//EN""http://www.springframework.org/dtd/spring-beans.dtd">
<beans>
<!--此时的id就必须与Order.java中所定义的OrderItem的对象名称一样了，不然就会找不到-->
<beanid="orderitem"class="org.jia.OrderItem">
<propertyname="orderdec"value="item00001"></property>
</bean>
<beanid="order"class="org.jia.Order"autowire="byName">
<propertyname="orderNum"value="order000007"></property>
</bean>
</beans>

getter&&setter方式第三种注入：byType

<?xmlversion="1.0"encoding="UTF-8"?>
<!DOCTYPEbeansPUBLIC"-//SPRING//DTDBEAN//EN""http://www.springframework.org/dtd/spring-beans.dtd">
<beans>
<!--按照byType注入则就与id没有关系，可以随便定义id ！！！但是不能出现多个此类的id-->
<beanid="orderitdfadafaem"class="org.jia.OrderItem">
<propertyname="orderdec"value="item00001"></property>
</bean>
<beanid="order"class="org.jia.Order"autowire="byType">
<propertyname="orderNum"value="order000007"></property>
</bean>
</beans>

关于构造器的注入：

autowire="constructor"
需要在Order.java中加入一个构造器
public Order(OrderItem item ){ orderitem = item; }

<?xmlversion="1.0"encoding="UTF-8"?>
<!DOCTYPEbeansPUBLIC"-//SPRING//DTDBEAN//EN""http://www.springframework.org/dtd/spring-beans.dtd">
<beans>
<beanid="orderItem"class="org.jia.OrderItem">
<propertyname="orderdec"value="item00001"></property>
</bean>
<beanid="order"class="org.jia.Order"autowire="constructor">
<propertyname="orderNum"value="order000007"></property>
</bean>
</beans>