在此示例中，我们使用 map 作为问题的答案，该问题的答案为键，而用户名为值。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，即getters和setters和displayInfo()方法以显示信息。
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;
//getters and setters
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"> <property name="id" value="1"></property> <property name="name" value="What is Java?"></property> <property name="answers"> <map> <entry key="Java is a programming language" value="Sonoo Jaiswal"></entry> <entry key="Java is a Platform" value="Sachin Yadav"></entry> </map> </property> </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();
}
}