Map Injection
Spring Inversion of Control (IoC ) also known as
Dependency Injection (DI ) is a process by which
objects define their dependencies with collaborating objects.
The following example shows map injection.
package com.bethecoder.tutorials.spring3.basic;
public class ComplexBean {
private java.util.Properties simpleProps;
private java.util.List simpleList;
private java.util.Map simpleMap;
private java.util.Set simpleSet;
public java.util.Properties getSimpleProps () {
return simpleProps;
}
public void setSimpleProps ( java.util.Properties simpleProps ) {
this .simpleProps = simpleProps;
}
public java.util.List getSimpleList () {
return simpleList;
}
public void setSimpleList ( java.util.List simpleList ) {
this .simpleList = simpleList;
}
public java.util.Map getSimpleMap () {
return simpleMap;
}
public void setSimpleMap ( java.util.Map simpleMap ) {
this .simpleMap = simpleMap;
}
public java.util.Set getSimpleSet () {
return simpleSet;
}
public void setSimpleSet ( java.util.Set simpleSet ) {
this .simpleSet = simpleSet;
}
}
package com.bethecoder.tutorials.spring3.basic;
public class Employee {
private int id;
private String name;
private double salary;
public Employee () {
super () ;
this .id = - 1 ;
this .name = "Unknown" ;
this .salary = 0 ;
}
public Employee ( int id, String name ) {
super () ;
this .id = id;
this .name = name;
this .salary = 20000 ;
}
public Employee ( int id, String name, double salary ) {
super () ;
this .id = id;
this .name = name;
this .salary = salary;
}
public int getId () {
return id;
}
public void setId ( int id ) {
this .id = id;
}
public String getName () {
return name;
}
public void setName ( String name ) {
this .name = name;
}
public double getSalary () {
return salary;
}
public void setSalary ( double salary ) {
this .salary = salary;
}
public String toString () {
return "Employee[" + id + ", " + name + ", " + salary + "]" ;
}
}
package com.bethecoder.tutorials.spring3.tests.collections;
import org.springframework.beans.factory.xml.XmlBeanFactory;
import org.springframework.core.io.ClassPathResource;
import com.bethecoder.tutorials.spring3.basic.ComplexBean;
public class MapInjection {
/**
* @param args
*/
public static void main ( String [] args ) {
XmlBeanFactory factory = new XmlBeanFactory (
new ClassPathResource ( "map_inj.xml" )) ;
ComplexBean complexBean = ( ComplexBean ) factory.getBean ( "complexBean" ) ;
System.out.println ( complexBean.getSimpleMap ()) ;
}
}
It gives the following output,
{emp2=Employee2, emp1=Employee[1, ABC, 90000.0], emp3=null}