Spring的注入方式

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 package org.jia;
2
3 public class Order {
4 private String orderNum;
5 @SuppressWarnings( " unused " )
6 private OrderItem orderitem;
7
8 public OrderItem getOrderitem() {
9 return orderitem;
10 }
11
12 public void setOrderitem(OrderItem orderitem) {
13 this .orderitem = orderitem;
14 }
15
16 public String getOrderNum() {
17 return orderNum;
18 }
19
20 public void setOrderNum(String orderNum) {
21 this .orderNum = orderNum;
22 }
23
24 }
25 package org.jia;
26
27 public class OrderItem {
28 private String orderdec;
29
30 public String getOrderdec() {
31 return orderdec;
32 }
33
34 public void setOrderdec(String orderdec) {
35 this .orderdec = orderdec;
36 }
37 }
38

getter&&setter方式第一种注入：

<? xml version="1.0" encoding="UTF-8" ?>
<! DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//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

<? xml version="1.0" encoding="UTF-8" ?>
<! DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//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

<? xml version="1.0" encoding="UTF-8" ?>
<! DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//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; }

<? xml version="1.0" encoding="UTF-8" ?>
<! DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//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 >

本文转自：http://www.blogjava.net/jiadong/archive/2007/08/29/140962.html