Spring 集合注入

　　Spring注入是spring框架的核心思想之一。在实际的开发中，我们经常会遇见这样一些类的注入，这些类中包含一些集合作为类的属性，那么要怎样想类中的集合注入数据呢？本文通过一个简单的示例向大家介绍一下如何在Spring中完成集合信息的注入。

　　首先建立一个最基本的web项目：springSetInjection。

　　干脆利落直接点击Finish，生成springSetInjection项目，框架如下图：

　　首先向项目中引入Spring开发必要的jar包，将相关包放在lib目录下：

　　然后在src目录下新建两个package:com.unionpay.beans 和 com.unionpay.controller。从包名就可以看出，这两个package的作用：一个用来装Bean类，一个用来装Controller类。

　　下面在beans包里面新建两个类：Person.java 和 Injection.java

　　Person.java

 1 package com.unionpay.beans;
 2 
 3 public class Person {
 4     
 5     private String username;
 6     private int age;
 7     private String address;
 8     
 9     
10     public Person(String username, int age, String address) {
11         super();
12         this.username = username;
13         this.age = age;
14         this.address = address;
15     }
16 
17     public Person() {
18         super();
19         // TODO Auto-generated constructor stub
20     }
21 
22     public String getUsername() {
23         return username;
24     }
25 
26     public void setUsername(String username) {
27         this.username = username;
28     }
29 
30     public int getAge() {
31         return age;
32     }
33 
34     public void setAge(int age) {
35         this.age = age;
36     }
37 
38     public String getAddress() {
39         return address;
40     }
41 
42     public void setAddress(String address) {
43         this.address = address;
44     }
45 
46     @Override
47     public String toString() {
48         return "Person [username=" + username + ", age=" + age + ", address=" + address + "]";
49     }
50 }

　　Injection.java

 1 package com.unionpay.beans;
 2 
 3 import java.util.List;
 4 import java.util.Map;
 5 import java.util.Properties;
 6 import java.util.Set;
 7 
 8 public class Injection {
 9     
10     private List<Object> lists;
11     private Set<Object> sets;
12     private Map<Object,Object> maps;
13     private Properties properties;
14     
15     public Injection(List<Object> lists, Set<Object> sets, Map<Object, Object> maps, Properties properties) {
16         super();
17         this.lists = lists;
18         this.sets = sets;
19         this.maps = maps;
20         this.properties = properties;
21     }
22 
23     public Injection() {
24         super();
25         // TODO Auto-generated constructor stub
26     }
27 
28     public List<Object> getLists() {
29         return lists;
30     }
31     
32     public void setLists(List<Object> lists) {
33         this.lists = lists;
34     }
35 
36     public Set<Object> getSets() {
37         return sets;
38     }
39 
40     public void setSets(Set<Object> sets) {
41         this.sets = sets;
42     }
43 
44     public Map<Object, Object> getMaps() {
45         return maps;
46     }
47 
48     public void setMaps(Map<Object, Object> maps) {
49         this.maps = maps;
50     }
51 
52     public Properties getProperties() {
53         return properties;
54     }
55 
56     public void setProperties(Properties properties) {
57         this.properties = properties;
58     }
59     
60     public String listInfo(){
61         return lists.toString();
62     }
63     
64     public String setInfo(){
65         return sets.toString();
66     }
67     
68     public String mapInfo(){
69         return maps.toString();
70     }
71     
72     public String propertiesInfo(){
73         return properties.toString();
74     }
75 }

　　然后在src目录下新建spring配置文件：config-beans.xml

　　config-beans.xml

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <beans xmlns="http://www.springframework.org/schema/beans"
 3     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"
 4     xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
 5 
 6     <bean id="injectionBean" class="com.unionpay.beans.Injection">
 7         <property name="lists">
 8             <list>
 9                 <value>data1</value>
10                 <ref bean="person" />
11                 <bean class="com.unionpay.beans.Person">
12                     <property name="username" value="jianxianwch"></property>
13                     <property name="age" value="27"></property>
14                     <property name="address" value="Shanghai"></property>
15                 </bean>
16             </list>
17         </property>
18 
19         <property name="sets">
20             <set>
21                 <value>data1</value>
22                 <ref bean="person" />
23                 <bean class="com.unionpay.beans.Person">
24                     <property name="username" value="jianxianwch"></property>
25                     <property name="age" value="27"></property>
26                     <property name="address" value="Shanghai"></property>
27                 </bean>
28             </set>
29         </property>
30 
31         <property name="maps">
32             <map>
33                 <entry key="key 1" value="data1"></entry>
34                 <entry key="key 2" value-ref="person"></entry>
35                 <entry key="key 3">
36                     <bean class="com.unionpay.beans.Person">
37                         <property name="username" value="jianxianwch"></property>
38                         <property name="age" value="27"></property>
39                         <property name="address" value="Shanghai"></property>
40                     </bean>
41                 </entry>
42             </map>
43         </property>
44         
45         <property name="properties">
46             <props>
47                 <prop key="username">admin</prop>
48                 <prop key="password">admin</prop>
49             </props>
50         </property>
51     </bean>
52 
53     <bean id="person" class="com.unionpay.beans.Person">
54         <constructor-arg name="username" value="jxwch"></constructor-arg>
55         <constructor-arg name="age" value="27"></constructor-arg>
56         <constructor-arg name="address" value="Anhui"></constructor-arg>
57     </bean>
58 </beans>

　　从配置文件中，我们可以看出将lists，sets，maps 和properties注入到了injectionBean中。Spring支持这四种集合的注入。

　　然后在controller包中建立InjectionController.java

 1 package com.unionpay.controller;
 2 
 3 import org.springframework.context.ApplicationContext;
 4 import org.springframework.context.support.ClassPathXmlApplicationContext;
 5 
 6 import com.unionpay.beans.Injection;
 7 
 8 public class InjectionController {
 9 
10     public static void main(String[] args) {
11         // TODO Auto-generated method stub
12         
13         ApplicationContext context = new ClassPathXmlApplicationContext("config-beans.xml");
14         
15         Injection injection = (Injection) context.getBean("injectionBean");
16         
17         System.out.println(injection.getLists());
18         System.out.println(injection.getSets());
19         System.out.println(injection.getMaps());
20         System.out.println(injection.getProperties());
21     }
22 
23 }

　　到目前为止，项目建立完成。右键InjectionController.java文件，选择Run As -->Java Application。终端打印出如下信息：

　　从终端打印信息中可以看见刚才注入的四种集合的数据，示例成功。

　　源码下载：test.zip