SpringIOC创建对象的方式案例

清疚 2021-11-09 13:38 269阅读 0赞

### 一、配置文件spring-ioc.xml相关代码 ###

<?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="userEntity1" class="com.zhq.pojo.UserEntity"/>
    
        
        <bean id="userEntity2" class="com.zhq.pojo.UserEntity">
            <constructor-arg name="name" value="猪大宝"></constructor-arg>
            <constructor-arg name="age" value="18"></constructor-arg>
        </bean>
    
        
        <bean id="objectFactory" class="com.zhq.pojo.ObjectFactory"/>
        <bean id="userEntity3" factory-bean="objectFactory" factory-method="getUserEntity"/>
    
        
        <bean id="userEntity4" class="com.zhq.pojo.ObjectFactory" factory-method="getStaticUserEntity"/>
    
    </beans>

### 二、相关实体类  ###

public class UserEntity {
        private String name;
        private Integer age;
    
        public UserEntity() {
            System.out.println("无参构造函数");
        }
    
        public UserEntity(String name, Integer age) {
            System.out.println("有参构造函数 name:" + name + "----" + 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;
        }
    
        @Override
        public String toString() {
            return "UserEntity [name=" + name + ", age=" + age + "]";
        }
    }

public class ObjectFactory {
        /**
         *
         * @methodDesc: 功能描述:(实例工厂方法)
         */
        public UserEntity getUserEntity() {
    
            System.out.println("ObjectFactory getUserEntity");
            return new UserEntity("zhangsan", 19);
        }
    
        /**
         *
         * @methodDesc: 功能描述:(静态工厂方法)
         */
        static public UserEntity getStaticUserEntity() {
            System.out.println("ObjectFactory getStaticUserEntity");
            return new UserEntity("static  zhangsan", 19);
        }
    }

### 三、测试方法  ###

public class SpringIOC {
        public static void main(String[] args) {
            //加载spring容器
            ClassPathXmlApplicationContext applicationContext=new ClassPathXmlApplicationContext("spring-ioc.xml");
    
            //1、无参构造
            UserEntity userEntity1 = (UserEntity) applicationContext.getBean("userEntity1");
            System.out.println(userEntity1);
    
            //2、有参构造
            UserEntity userEntity2 = (UserEntity) applicationContext.getBean("userEntity2");
            System.out.println(userEntity2);
    
            //3、实例工厂
            UserEntity userEntity3 = (UserEntity) applicationContext.getBean("userEntity3");
            System.out.println(userEntity3);
    
            //3、静态工厂
            UserEntity userEntity4 = (UserEntity) applicationContext.getBean("userEntity4");
            System.out.println(userEntity4);
        }
    }

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