setter method Injection in spring framework

setter method Injection in spring framework is very simple, let's go to learn.

We can inject the dependency by setter method also. The <property> subelement of <bean> is used for setter injection. Here we are going to inject

1. primitive and String-based values
2. Dependent object (contained object)
3. Collection values etc.

Injecting primitive and string-based values by setter method

Let's see the simple example to inject primitive and string-based values by setter method. We have created three files here:

• Employee.java
• applicationContext.xml
• Test.java

Employee.java file
It is a simple class containing three fields id, name and city with its setters and getters and a method to display these informations.

1. package com.tpyyes;  
2. public class Employee {  
3. private int id;  
4. private String name;  
5. private String city;  
6.   
7. public int getId() {  
8.     return id;  
9. }  
10. public void setId(int id) {  
11.     this.id = id;  
12. }  
13. public String getName() {  
14.     return name;  
15. }  
16. public void setName(String name) {  
17.     this.name = name;  
18. }  
19.   
20. public String getCity() {  
21.     return city;  
22. }  
23. public void setCity(String city) {  
24.     this.city = city;  
25. }  
26. void display(){  
27.     System.out.println(id+" "+name+" "+city);  
28. }  
29.   
30. }  

applicationContext.xml

We are providing the information into the bean by this file. The property element invokes the setter method. The value subelement of property will assign the specified value.

1. <?xml version="1.0" encoding="UTF-8"?>  
2. <beans  
3.     xmlns="http://www.springframework.org/schema/beans"  
4.     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  
5.     xmlns:p="http://www.springframework.org/schema/p"  
6.     xsi:schemaLocation="http://www.springframework.org/schema/beans  
7.                 http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">  
8.   
9. <bean id="emp" class="com.tpyyes.Employee">  
10. <property name="id">  
11. <value>20</value>  
12. </property>  
13. <property name="name">  
14. <value>Arun</value>  
15. </property>  
16. <property name="city">  
17. <value>ghaziabad</value>  
18. </property>  
19.   
20. </bean>  
21.   
22. </beans>  

Test.java

This class gets the bean from the applicationContext.xml file and calls the display method.

1. package com.tpyyes;  
2.   
3. import org.springframework.beans.factory.BeanFactory;  
4. import org.springframework.beans.factory.xml.XmlBeanFactory;  
5. import org.springframework.core.io.*;  
6.   
7. public class Test {  
8.     public static void main(String[] args) {  
9.           
10.         Resource r=new ClassPathResource("applicationContext.xml");  
11.         BeanFactory factory=new XmlBeanFactory(r);  
12.           
13.         Employee e=(Employee)factory.getBean("emp");  
14.         s.display();  
15.           
16.     }  
17. }  

Output:20 Arun ghaziabad