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

1 packageorg.jia;
2
3 public classOrder{
4 privateStringorderNum;
5@SuppressWarnings("unused")
6 privateOrderItem orderitem;
7
8 publicOrderItemgetOrderitem(){
9 returnorderitem;
10}
11
12 public voidsetOrderitem(OrderItemorderitem){
13 this.orderitem=orderitem;
14}
15
16 publicStringgetOrderNum(){
17 returnorderNum;
18}
19
20 public voidsetOrderNum(StringorderNum){
21 this.orderNum=orderNum;
22}
23
24}
25 packageorg.jia;
26
27 public classOrderItem{
28 privateStringorderdec;
29
30 publicStringgetOrderdec(){
31 returnorderdec;
32}
33
34 public voidsetOrderdec(Stringorderdec){
35 this.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 >
< bean id ="orderItem" class ="org.jia.OrderItem" >
< property name ="orderdec" value ="item00001" ></ property >
</ bean >
< bean id ="order" class ="org.jia.Order" >
<!-----注入变量 名字必须与类中的名字一样------->
< property name ="orderNum" value ="order000007" ></ property >
<！--注入对象 名字为orderitem，所属的类的应用id为orderItem-->
< property name ="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-->
< bean id ="orderitem" class ="org.jia.OrderItem" >
< property name ="orderdec" value ="item00001" ></ property >
</ bean >
< bean id ="order" class ="org.jia.Order" autowire ="byName" >
< property name ="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-->
< bean id ="orderitdfadafaem" class ="org.jia.OrderItem" >
< property name ="orderdec" value ="item00001" ></ property >
</ bean >
< bean id ="order" class ="org.jia.Order" autowire ="byType" >
< property name ="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 >
< bean id ="orderItem" class ="org.jia.OrderItem" >
< property name ="orderdec" value ="item00001" ></ property >
</ bean >
< bean id ="order" class ="org.jia.Order" autowire ="constructor" >
< property name ="orderNum" value ="order000007" ></ property >
</ bean >
</ beans >