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

 package com.unionpay.beans;

 public class Person {

     private String username;
     private int age;
     private String address;

     public Person(String username, int age, String address) {
         super();
         this.username = username;
         this.age = age;
         this.address = address;
     }

     public Person() {
         super();
         // TODO Auto-generated constructor stub
     }

     public String getUsername() {
         return username;
     }

     public void setUsername(String username) {
         this.username = username;
     }

     public int getAge() {
         return age;
     }

     public void setAge(int age) {
         this.age = age;
     }

     public String getAddress() {
         return address;
     }

     public void setAddress(String address) {
         this.address = address;
     }

     @Override
     public String toString() {
         return "Person [username=" + username + ", age=" + age + ", address=" + address + "]";
     }
 }

　　Injection.java

 package com.unionpay.beans;

 import java.util.List;
 import java.util.Map;
 import java.util.Properties;
 import java.util.Set;

 public class Injection {

     private List<Object> lists;
     private Set<Object> sets;
     private Map<Object,Object> maps;
     private Properties properties;

     public Injection(List<Object> lists, Set<Object> sets, Map<Object, Object> maps, Properties properties) {
         super();
         this.lists = lists;
         this.sets = sets;
         this.maps = maps;
         this.properties = properties;
     }

     public Injection() {
         super();
         // TODO Auto-generated constructor stub
     }

     public List<Object> getLists() {
         return lists;
     }

     public void setLists(List<Object> lists) {
         this.lists = lists;
     }

     public Set<Object> getSets() {
         return sets;
     }

     public void setSets(Set<Object> sets) {
         this.sets = sets;
     }

     public Map<Object, Object> getMaps() {
         return maps;
     }

     public void setMaps(Map<Object, Object> maps) {
         this.maps = maps;
     }

     public Properties getProperties() {
         return properties;
     }

     public void setProperties(Properties properties) {
         this.properties = properties;
     }

     public String listInfo(){
         return lists.toString();
     }

     public String setInfo(){
         return sets.toString();
     }

     public String mapInfo(){
         return maps.toString();
     }

     public String propertiesInfo(){
         return properties.toString();
     }
 }

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

　　config-beans.xml

 <?xml version="1.0" encoding="UTF-8"?>
 <beans xmlns="http://www.springframework.org/schema/beans"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"
     xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">

     <bean id="injectionBean" class="com.unionpay.beans.Injection">
         <property name="lists">
             <list>
                 <value>data1</value>
                 <ref bean="person" />
                 <bean class="com.unionpay.beans.Person">
                     <property name="username" value="jianxianwch"></property>
                     <property name="age" value=""></property>
                     <property name="address" value="Shanghai"></property>
                 </bean>
             </list>
         </property>

         <property name="sets">
             <set>
                 <value>data1</value>
                 <ref bean="person" />
                 <bean class="com.unionpay.beans.Person">
                     <property name="username" value="jianxianwch"></property>
                     <property name="age" value=""></property>
                     <property name="address" value="Shanghai"></property>
                 </bean>
             </set>
         </property>

         <property name="maps">
             <map>
                 <entry key="key 1" value="data1"></entry>
                 <entry key="key 2" value-ref="person"></entry>
                 <entry key="key 3">
                     <bean class="com.unionpay.beans.Person">
                         <property name="username" value="jianxianwch"></property>
                         <property name="age" value=""></property>
                         <property name="address" value="Shanghai"></property>
                     </bean>
                 </entry>
             </map>
         </property>

         <property name="properties">
             <props>
                 <prop key="username">admin</prop>
                 <prop key="password">admin</prop>
             </props>
         </property>
     </bean>

     <bean id="person" class="com.unionpay.beans.Person">
         <constructor-arg name="username" value="jxwch"></constructor-arg>
         <constructor-arg name="age" value=""></constructor-arg>
         <constructor-arg name="address" value="Anhui"></constructor-arg>
     </bean>
 </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

 package com.unionpay.controller;

 import org.springframework.context.ApplicationContext;
 import org.springframework.context.support.ClassPathXmlApplicationContext;

 import com.unionpay.beans.Injection;

 public class InjectionController {

     public static void main(String[] args) {
         // TODO Auto-generated method stub

         ApplicationContext context = new ClassPathXmlApplicationContext("config-beans.xml");

         Injection injection = (Injection) context.getBean("injectionBean");

         System.out.println(injection.getLists());
         System.out.println(injection.getSets());
         System.out.println(injection.getMaps());
         System.out.println(injection.getProperties());
     }

 }

　　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