通過使用 bean 的 parent 屬性，我們可以指定Bean之間的繼承關(guān)系。在這種情況下，父bean的值將被繼承到當(dāng)前bean。
讓我們看一下繼承bean的簡(jiǎn)單示例。
Employee.java
此該類包含三個(gè)屬性，三個(gè)構(gòu)造函數(shù)和用于顯示值的show()方法。
package com.nhooo;
public class Employee {
private int id;
private String name;
private Address address;
public Employee() {}
public Employee(int id, String name) {
super();
this.id = id;
this.name = name;
}
public Employee(int id, String name, Address address) {
super();
this.id = id;
this.name = name;
this.address = address;
}
void show(){
System.out.println(id+" "+name);
System.out.println(address);
}
}
Address.java
package com.nhooo;
public class Address {
private String addressLine1,city,state,country;
public Address(String addressLine1, String city, String state, String country) {
super();
this.addressLine1 = addressLine1;
this.city = city;
this.state = state;
this.country = country;
}
public String toString(){
return addressLine1+" "+city+" "+state+" "+country;
}
}
applicationContext.xml
<?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="e1" class="com.nhooo.Employee"> <constructor-arg value="101"></constructor-arg> <constructor-arg value="Sachin"></constructor-arg> </bean> <bean id="address1" class="com.nhooo.Address"> <constructor-arg value="21,Lohianagar"></constructor-arg> <constructor-arg value="Ghaziabad"></constructor-arg> <constructor-arg value="UP"></constructor-arg> <constructor-arg value="USA"></constructor-arg> </bean> <bean id="e2" class="com.nhooo.Employee" parent="e1"> <constructor-arg ref="address1"></constructor-arg> </bean> </beans>
Test.java
此類從applicationContext.xml文件獲取Bean并調(diào)用show方法。
package com.nhooo;
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);
Employee e1=(Employee)factory.getBean("e2");
e1.show();
}
}