Example of Setter Injection with Non-String Mapping Example of Setter Injection (with related objects)

Setter injection and Map example

In this example, we use map The answer to the question is the key, and the username is the value. Here, we use both keys and values as strings.

Like the previous example, it is a forum example where A question can have multiple answers.

Question.java

This class contains three properties, namely getters and setters and the displayInfo() method to display information.

Example

package com.w3codebox;
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 of entry Properties are used to define key and value information.

Example

<?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.w3codebox.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

This class retrieves a Bean from the applicationContext.xml file and calls the displayInfo() method.

Example

package com.w3codebox;
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();
　　　　
}
}

Example of Setter Injection with Non-String Mapping Example of Setter Injection (with related objects)

Spring Tutorial

Setter injection and Map example