Spring裝配集合屬性

在Spring中可以裝配4種集合類型屬性：List、set、Map和Properties。與這四種集合對應的標籤是、、
、。CollectionBean是一個包含上述4種集合類型的JavaBean，代碼如下：

package chapter22;import java.util.List;import java.util.Map;import java.util.Properties;import java.util.Set;public class CollectionBean {    private List myList;    private String myArray[];    private Set mySet;    private Map myMap;    private Properties myProperties;        public List getMyList() {        return myList;    }    public void setMyList(List myList) {        System.out.println("set List類型："+myList.getClass().getName());        this.myList = myList;    }    public String[] getMyArray() {        return myArray;    }    public void setMyArray(String[] myArray) {        this.myArray = myArray;    }    public Set getMySet() {        return mySet;    }    public void setMySet(Set mySet) {        System.out.println("set Set類型："+mySet.getClass().getName());        this.mySet = mySet;    }    public Map getMyMap() {        return myMap;    }    public void setMyMap(Map myMap) {        System.out.println("set Map類型："+myMap.getClass().getName());        this.myMap = myMap;    }    public Properties getMyProperties() {        return myProperties;    }    public void setMyProperties(Properties myProperties) {        System.out.println("set Properties類型："+myProperties.getClass().getName());        this.myProperties = myProperties;    }}

下面是裝配上述4中集合類型屬性的配置代碼

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:p="http://www.springframework.org/schema/p"    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">    <bean id="helloservice" class="chapter22.HelloServiceImpl">        <property name="greeting" value="greeting Xu Wei">property>bean>    <bean id="myBean" class="chapter22.MyBean">        <property name="hello">            <ref bean="helloservice" />property>        <property name="strName" value="Xu Wei">property>bean>    <bean id="CollectionBean" class="chapter22.CollectionBean">    <property name="myList">            <list><value>abcdvalue>                <idref bean="myBean">idref>                list>        property><property name="myMap">            <map>                <entry>                    <key>                        <value>hellovalue>key>                    <value>1234value>entry>                <entry key="abcd">                    <ref bean="helloservice" />entry>                <entry>                    <key>                        <ref bean="helloservice" >ref>key>                    <ref bean="myBean" >ref>entry>map>property>        <property name="mySet">            <set>                <value>testvalue>                <ref bean="myBean">ref>set>property>                        <property name="myProperties">            <props><prop key="abcd">value1prop>                <prop key="prop">myPropprop>props>property>        <property name="myArray">            <list>                <value>myArrayvalue>                <idref bean="helloservice" >idref>list>property>bean>beans>

下面的TestCollectionContext.java代碼使用ApplicationContext介面的getBean方法建立了CollectionBean對象，並訪問了相關屬性。

package chapter22;import org.springframework.context.ApplicationContext;import org.springframework.context.support.FileSystemXmlApplicationContext;public class TestCollectionBean {    public static void main(String args[])    {        ApplicationContext ctx=new FileSystemXmlApplicationContext("src//applicationContext.xml");/*在建立ctx對象執行個體以後，applicationContext.xml配置中涉及到的Bean的set方法都被調用了。 *單單執行ApplicationContext ctx=new FileSystemXmlApplicationContext("src//applicationContext.xml"); *的輸出結果是： *log4j:WARN No appenders could be found for logger (org.springframework.context.support.FileSystemXmlApplicationContext). *log4j:WARN Please initialize the log4j system properly. *setGreeting()方法被調用 *setHello()方法被調用 *setStrName()方法被調用 *set List類型：java.util.ArrayList *set Map類型：java.util.LinkedHashMap *set Set類型：java.util.LinkedHashSet *set Properties類型：java.util.Properties */            //建立CollectionBean對象cb。        CollectionBean cb=(CollectionBean)ctx.getBean("CollectionBean");                System.out.println("------測試List------");        for(String s:cb.getMyList())            System.out.println(s);        System.out.println("------測試Array------");        for(String s:cb.getMyArray())            System.out.println(s);        System.out.println("------測試Set------");        for(Object obj:cb.getMySet())            System.out.println(obj.getClass().getName());        System.out.println("------測試Map------");        //Map其實就是key-value的索引值對。cb.getMyMap().get(key)是要找到key所對應的value。        for(Object key:cb.getMyMap().keySet())            System.out.println(key+"="+cb.getMyMap().get(key));        System.out.println("------測試Properties------");        for(Object key:cb.getMyProperties().keySet())            System.out.println(key+"="+cb.getMyProperties().get(key));    }}

輸出結果：

log4j:WARN No appenders could be found for logger (org.springframework.context.support.FileSystemXmlApplicationContext).log4j:WARN Please initialize the log4j system properly.setGreeting()方法被調用setHello()方法被調用setStrName()方法被調用set List類型：java.util.ArrayListset Map類型：java.util.LinkedHashMapset Set類型：java.util.LinkedHashSetset Properties類型：java.util.Properties------測試List------abcdmyBean------測試Array------myArrayhelloservice------測試Set------java.lang.Stringchapter22.MyBean------測試Map------hello=1234abcd=chapter22.HelloServiceImpl@e70e30chapter22.HelloServiceImpl@e70e30=chapter22.MyBean@154864a------測試Properties------abcd=value1prop=myProp