IOC(三)

Bean管理指的是Spring创建对象和Spring注入属性

Spring创建对象即之前所说的使用xml配置 id 和 class. Spring注入属性(也称注入依赖)有两种方式: 使用set方法进行注入和使用有参构造进行注入

使用set方法注入属性示例:

类文件:

package com.ryan.spring5;

public class ClassTestSet {
    String name;
    Integer age;

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

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

    public void test(){
        System.out.println(name + "::" + age);
    }
}

xml配置文件:

<?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">

    <!--配置User对象创建-->
    <bean id="animal" class="com.ryan.spring5.ClassTestSet">
        <property name="age" value="4"></property>
        <property name="name" value="Doggy"></property>
    </bean>
</beans>

调用对象文件:

public class TestSpring5 {

    public static void main(String[] args){

        //1.加载Spring配置文件
        ApplicationContext context = new FileSystemXmlApplicationContext("conf\beans1.xml");
        //2.获取配置创建的对象
        ClassTestSet animal = context.getBean("animal", ClassTestSet.class);

        animal.test();
    }
}

测试结果:

使用有参构造函数注入属性实例:

类文件:

package com.ryan.spring5;

public class ClassTestConstruction {
    String name;
    int age;

    public ClassTestConstruction(String name, int age) {
        this.name = name;
        this.age = age;
    }

    public void test(){
        System.out.println(name + "::" + age);
    }
}

xml配置文件:

<?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">

    <!--配置User对象创建-->
    <bean id="person" class="com.ryan.spring5.ClassTestConstruction">
        <constructor-arg name="name" value="章北海"></constructor-arg>
        <constructor-arg name="age" value="30"></constructor-arg>
    </bean>
</beans>

或(index=0表示第一个参数, index=1表示第二个参数):

<?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">

    <!--配置User对象创建-->
    <bean id="person" class="com.ryan.spring5.ClassTestConstruction">
        <constructor-arg index="0" value="章北海"></constructor-arg>
        <constructor-arg index="1" value="30"></constructor-arg>
    </bean>
</beans>

调用对象文件:

public class TestSpring5 {

    public static void main(String[] args){

        //1.加载Spring配置文件
        ApplicationContext context = new FileSystemXmlApplicationContext("conf\beans1.xml");
        //2.获取配置创建的对象
        ClassTestConstruction person = context.getBean("person", ClassTestConstruction.class);

        person.test();
    }
}

测试结果:

*注: 此外还有一种使用p名称空间注入属性的方式, 需要修改xml约束, 用的不多, 暂不记录