在此示例中,我们使用
map
作为具有已发布用户名答案的答案。在这里,我们将键和值对都用作字符串。
像前面的示例一样,它是论坛的示例,其中
一个问题可以有多个答案
。
Question.java
此类包含三个属性,两个构造函数和用于显示信息的displayInfo()方法。
package com.nhooo; import java.util.Iterator; import java.util.Map; import java.util.Set; import java.util.Map.Entry; public class Question { private int id; private String name; private Map<String,String> answers; public Question() {} public Question(int id, String name, Map<String, String> answers) { super(); this.id = id; this.name = name; this.answers = answers; } public void displayInfo(){ System.out.println("question id:"+id); System.out.println("question name:"+name); System.out.println("Answers...."); Set<Entry<String, String>> set=answers.entrySet(); Iterator<Entry<String, String>> itr=set.iterator(); while(itr.hasNext()){ Entry<String,String> entry=itr.next(); System.out.println("Answer:"+entry.getKey()+" Posted By:"+entry.getValue()); } } }
applicationContext.xml
map
的
entry 属性用于定义键和值信息。
<?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-3.0.xsd"> <bean id="q" class="com.nhooo.Question"> <constructor-arg value="11"></constructor-arg> <constructor-arg value="What is Java?"></constructor-arg> <constructor-arg> <map> <entry key="Java is a Programming Language" value="Ajay Kumar"></entry> <entry key="Java is a Platform" value="John Smith"></entry> <entry key="Java is an Island" value="Raj Kumar"></entry> </map> </constructor-arg> </bean> </beans>
Test.java
此类从applicationContext.xml文件获取Bean并调用displayInfo()方法。
package com.nhooo; import org.springframework.beans.factory.BeanFactory; import org.springframework.beans.factory.xml.XmlBeanFactory; import org.springframework.core.io.ClassPathResource; import org.springframework.core.io.Resource; public class Test { public static void main(String[] args) { Resource r=new ClassPathResource("applicationContext.xml"); BeanFactory factory=new XmlBeanFactory(r); Question q=(Question)factory.getBean("q"); q.displayInfo(); } }