📅  最后修改于: 2020-12-04 07:47:10             🧑  作者: Mango
在此示例中,我们将地图用作具有Answer和User的答案。在这里,我们将键和值对都用作对象。答案具有自己的信息,例如answerId,答案和postedDate,用户具有自己的信息,例如userId,用户名,emailId。
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。
此类包含三个属性,即getters&setters和displayInfo()方法以显示信息。
package com.javatpoint;
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 answers;
//getters and setters
public void displayInfo(){
System.out.println("question id:"+id);
System.out.println("question name:"+name);
System.out.println("Answers....");
Set> set=answers.entrySet();
Iterator> itr=set.iterator();
while(itr.hasNext()){
Entry entry=itr.next();
Answer ans=entry.getKey();
User user=entry.getValue();
System.out.println("Answer Information:");
System.out.println(ans);
System.out.println("Posted By:");
System.out.println(user);
}
}
}
package com.javatpoint;
import java.util.Date;
public class Answer {
private int id;
private String answer;
private Date postedDate;
public Answer() {}
public Answer(int id, String answer, Date postedDate) {
super();
this.id = id;
this.answer = answer;
this.postedDate = postedDate;
}
public String toString(){
return "Id:"+id+" Answer:"+answer+" Posted Date:"+postedDate;
}
}
package com.javatpoint;
public class User {
private int id;
private String name,email;
public User() {}
public User(int id, String name, String email) {
super();
this.id = id;
this.name = name;
this.email = email;
}
public String toString(){
return "Id:"+id+" Name:"+name+" Email Id:"+email;
}
}
entry元素的key-ref和value-ref属性用于定义映射中bean的引用。
此类从applicationContext.xml文件获取Bean,并调用displayInfo()方法以显示信息。
package com.javatpoint;
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();
}
}