FactoryBean

FactoryBean Demo

项目工程结构

FactoryBeanTest.java

import org.springframework.context.support.ClassPathXmlApplicationContext;

public class FactoryBeanTest {

    public static void main(String[] args){
        ClassPathXmlApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");
        Object object=  applicationContext.getBean("factoryBeanPojo");
        FactoryBeanPojo factoryBeanPojo= (FactoryBeanPojo) applicationContext.getBean("&factoryBeanPojo");
        System.out.println(object.getClass().getName());
        System.out.println(factoryBeanPojo.getClass().getName());
    }

}

FactoryBeanPojo.java

import org.springframework.beans.factory.FactoryBean;

public class FactoryBeanPojo implements FactoryBean {

    private String type;

    @Override
    public Object getObject() throws Exception {
        if("dog".equals(type)){
            return new Dog();
        }else{
            return new Cat();
        }

    }

    @Override
    public Class getObjectType() {
        return Cat.class;
    }

    @Override
    public boolean isSingleton() {
        return true;
    }

    public String getType() {
        return type;
    }

    public void setType(String type) {
        this.type = type;
    }

}

Dog.java

public class Dog {

    private String dogName;

    public String getDogName() {
        return dogName;
    }

    public void setDogName(String dogName) {
        this.dogName = dogName;
    }

}

Cat.java

public class Cat {

    private String catName;
    public String getCatName() {
        return catName;
    }
    public void setCatName(String catName) {
        this.catName = catName;
    }

}

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"
       xsi:schemaLocation="http://www.springframework.org/schema/beans 
       http://www.springframework.org/schema/beans/spring-beans.xsd">

    <bean id="student" class="com.supremepole.springfactorybean.Dog">
        <property name="dogName" value="little-yellow" />
    </bean>

    <bean id="school" class="com.supremepole.springfactorybean.Cat">
    </bean>

    <bean id="factoryBeanPojo" class="com.supremepole.springfactorybean.FactoryBeanPojo">
        <property name="type" value="dog" />
    </bean>

</beans>