使用非字符串映射(具有依赖对象)的Setter注入示例 _setter

使用非字符串映射的Setter注入

【使用非字符串映射(具有依赖对象)的Setter注入示例】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。
Question.java
此类包含三个属性, 即getters＆setters和displayInfo()方法以显示信息。

package com.srcmini; 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< Answer, User> answers; //getters and setterspublic void displayInfo(){ System.out.println("question id:"+id); System.out.println("question name:"+name); System.out.println("Answers...."); Set< Entry< Answer, User> > set=answers.entrySet(); Iterator< Entry< Answer, User> > itr=set.iterator(); while(itr.hasNext()){ Entry< Answer, User> 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); } } }

Answer.java

package com.srcmini; 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; } }

User.java

package com.srcmini; 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; } }

applicationContext.xml
entry元素的key-ref和value-ref属性用于定义映射中bean的引用。

< ?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="answer1" class="com.srcmini.Answer"> < property name="id" value="http://www.srcmini.com/1"> < /property> < property name="answer" value="http://www.srcmini.com/Java is a Programming Language"> < /property> < property name="postedDate" value="http://www.srcmini.com/12/12/2001"> < /property> < /bean> < bean id="answer2" class="com.srcmini.Answer"> < property name="id" value="http://www.srcmini.com/2"> < /property> < property name="answer" value="http://www.srcmini.com/Java is a Platform"> < /property> < property name="postedDate" value="http://www.srcmini.com/12/12/2003"> < /property> < /bean> < bean id="user1" class="com.srcmini.User"> < property name="id" value="http://www.srcmini.com/1"> < /property> < property name="name" value="http://www.srcmini.com/Arun Kumar"> < /property> < property name="email" value="http://www.srcmini.com/arun@gmail.com"> < /property> < /bean> < bean id="user2" class="com.srcmini.User"> < property name="id" value="http://www.srcmini.com/2"> < /property> < property name="name" value="http://www.srcmini.com/Varun Kumar"> < /property> < property name="email" value="http://www.srcmini.com/Varun@gmail.com"> < /property> < /bean> < bean id="q" class="com.srcmini.Question"> < property name="id" value="http://www.srcmini.com/1"> < /property> < property name="name" value="http://www.srcmini.com/What is Java?"> < /property> < property name="answers"> < map> < entry key-ref="answer1" value-ref="user1"> < /entry> < entry key-ref="answer2" value-ref="user2"> < /entry> < /map> < /property> < /bean> < /beans>

Test.java
此类从applicationContext.xml文件获取Bean, 然后调用displayInfo()方法以显示信息。

package com.srcmini; 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(); } }

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