Spring4学习回顾之路08- FactoryBean配置Bean

建立Student.java

package com.lql.srping04;

/**
 * @author: lql
 * @date: 2019.10.28
 * Description:
 */
public class Student {

    private String name;
    private Integer age;

    @Override
    public String toString() {
        return "Student{" +
                "name='" + name + '\'' +
                ", age=" + age +
                '}';
    }

    public Student() {
    }

    public Student(String name, Integer age) {
        this.name = name;
        this.age = age;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }
}

建立StudentFactoryBean.java

package com.lql.srping04;

import org.springframework.beans.factory.FactoryBean;

/**
 * @author: lql
 * @date: 2019.10.28
 * Description:
 * Created with IntelliJ IDEA
 */
public class StudentFactoryBean implements FactoryBean<Student> {
    /**
     *
     * @return  返回bean的对象
     * @throws Exception
     */
    @Override
    public Student getObject() throws Exception {
        return new Student("张无忌",17);
    }

    /**
     *
     * @return 返回bean的类型
     */
    @Override
    public Class<?> getObjectType() {
        return Student.class;
    }

    /**
     *
     * @return 是否单例
     */
    @Override
    public boolean isSingleton() {
        return true;
    }
}

配置：

<?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.lql.srping04.StudentFactoryBean"></bean>
</beans>

测试：

package com.lql.srping04;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

/**
 * @author: lql
 * @date: 2019.10.28
 * Description:
 */
public class StudetnTest {
    public static void main(String[] args) {
        ApplicationContext app = new ClassPathXmlApplicationContext("spring04.xml");
//        Student student = app.getBean("studentfactory", Student.class);
        Student student = app.getBean("student", Student.class);
        System.out.println(student);
    }
}

结果：

信息: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@37bba400: startup date [Mon Oct 28 15:03:41 GMT+08:00 2019]; root of context hierarchy
十月 28, 2019 3:03:41 下午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
信息: Loading XML bean definitions from class path resource [spring04.xml]
Student{name='张无忌', age=17}

需要注意的是：自定义的FactoryBean需要实现“FactoryBean”接口。返回实例则是getObject()返回的实例