factory-method

太过爱你忘了你带给我的痛 2023-07-18 04:46 16阅读 0赞

**目录**

1、概述

2、示例

创建User类

创建 factory-method 类

spring配置

spring引导类

运行结果

--------------------

# 1、概述 #

factory-method：通过工厂类创建Spring bean。两种方式：一种静态方法，一种动态方法。

# 2、示例 #

## 创建User类 ##

package thinking.in.spring.boot.samples.spring5.bean;
    
    public class User {
        private int id;
        private String name;
    
        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;
        }
    
        @Override
        public String toString() {
            return "User{" +
                    "id=" + id +
                    ", name='" + name + '\'' +
                    '}';
        }
    }

## 创建 factory-method 类 ##

package thinking.in.spring.boot.samples.spring5.factorybean;
    
    import thinking.in.spring.boot.samples.spring5.bean.User;
    
    /**
     * 演示 factory-method
     */
    public class UserFactory {
    
    
        public static User getStaticUser() throws Exception {
            User user = new User();
            user.setId(100);
            user.setName("静态工厂方法创建User");
            return user;
        }
    
        public User getDynamicUser() throws Exception {
            User user = new User();
            user.setId(200);
            user.setName("动态工厂方法创建User");
            return user;
        }
    
    }

## spring配置 ##

<bean id="staticFactoryMethod" class="thinking.in.spring.boot.samples.spring5.factorybean.UserFactory"
            factory-method="getStaticUser" />
    
        
        <bean id="userFactory" class="thinking.in.spring.boot.samples.spring5.factorybean.UserFactory" />
        <bean id="dynamicFactoryMethod" factory-bean="userFactory"
            factory-method="getDynamicUser" />

## spring引导类 ##

package thinking.in.spring.boot.samples.spring5.bootstrap;
    
    import org.springframework.beans.factory.support.DefaultListableBeanFactory;
    import org.springframework.beans.factory.xml.XmlBeanFactory;
    import org.springframework.core.io.ClassPathResource;
    import thinking.in.spring.boot.samples.spring5.customlabel.CustomLabel;
    import thinking.in.spring.boot.samples.spring5.bean.User;
    import thinking.in.spring.boot.samples.spring5.factorybean.UserFactoryBean;
    
    public class XmlBeanFactoryBootstrap {
    
        public static void main(String[] args) {
            DefaultListableBeanFactory defaultListableBeanFactory = new XmlBeanFactory(new ClassPathResource("application-context.xml"));
    
    
            /**
             * factory-method
             */
            User staticUser = (User) defaultListableBeanFactory.getBean("staticFactoryMethod");
            System.out.println("factory-method 实例化的User对象：" + staticUser);
            User dynamicUser = (User) defaultListableBeanFactory.getBean("dynamicFactoryMethod");
            System.out.println("factory-method 实例化的User对象：" + dynamicUser);
    
        }
    }

## 运行结果 ##

factory-method 实例化的User对象：User{id=100, name='静态工厂方法创建User'}
    factory-method 实例化的User对象：User{id=200, name='动态工厂方法创建User'}