使用自动注入byType的方式对对象属性进行赋值

1. 写类对象

package com.bjpowernode.ba05;

public class Student {
    private String name;
    private int age;
    private School school;

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

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

    public void setSchool(School school) {
        this.school = school;
    }

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

package com.bjpowernode.ba05;

public class School {
    private String name;
    private String address;

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

    public void setAddress(String address) {
        this.address = address;
    }

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

package com.bjpowernode.ba05;

public class PrimarySchool extends School {
}

2. 维护spring容器属性

<?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">
    <!--使用自动注入的方式对引用类型的属性进行赋值-->
    <!--
    引用类型的自动注入：spring框架根据某些规则可以给应用类型赋值。使用的规则常用的是byName，byType
    1. byName（按照名称注入）要求要注入的引用类型属性名称和bean标签的id名称一致，并且属性类型一致
    2. byType（按类型注入）java类中引用类型的数据类型和spring容器中（配置文件）<bean>de class属性是同源关系的
                          这样的bean能够赋值给引用类型
              同源就是一类的意思
              1. java类中引用类型的数据类型和bean的class的值是一样的
              2. java类中引用类型的数据类型和bean的class的值是父子关系的
              3. java类中的引用类型的数据类型和bean的class的值是接口和实现类关系的
    -->
    <bean id="myStudent" class="com.bjpowernode.ba05.Student" autowire="byType">
        <property name="age" value="13"/>
        <property name="name" value="xiaohui"/>
    </bean>

<!--    <bean id="mySchool" class="com.bjpowernode.ba05.School">
        <property name="name" value="山东建筑大学"/>
        <property name="address" value="凤鸣路"/>
    </bean>-->
    <bean id="myPrimarySchool" class="com.bjpowernode.ba05.PrimarySchool">
        <property name="name" value="ly小学"/>
        <property name="address" value="ly"/>
    </bean>
</beans>

3. 使用spring创建对象并使用

package com.bjpowernode;

import com.bjpowernode.ba05.Student;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class MyTest05 {
    @Test
    public void test05(){
        /*使用byType的方式实现对象属性的自动注入*/
        String conf = "ba05/applicationContext.xml";
        ApplicationContext ac = new ClassPathXmlApplicationContext(conf);
        Student student = (Student) ac.getBean("myStudent");
        System.out.println(student);
    }
}