流程

1、导入依赖

 <!-- https://mvnrepository.com/artifact/org.springframework/spring-webmvc --><dependency><groupId>org.springframework</groupId><artifactId>spring-webmvc</artifactId><version>5.3.3</version></dependency>

2、创建实体类

package pojo;public class Teacher {private String name;private Integer age;public Teacher() {}public Teacher(String name, Integer age) {this.name = name;this.age = age;}public void setName(String name) {this.name = name;}public void setAge(Integer age) {this.age = age;}@Overridepublic String toString() {return "Teacher{" +"name='" + name + '\'' +", age=" + age +'}';}
}

3、配置spring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"><bean id="teacher1" class="pojo.Teacher"><property name="name" value="john"/><property name="age" value="55"/></bean>
</beans>

4、测试

@Testpublic void test1(){//ClassPathXmlApplicationContext：用于加载spring配置文件到spring容器中进行bean的初始化ApplicationContext context = new ClassPathXmlApplicationContext("bean.xml");//getBean()：可以通过配置文件中的id进行查找，并返回对应的结果Teacher teacher1 = context.getBean("teacher1", Teacher.class);System.out.println(teacher1);}/**output:  Teacher{name='john', age=55}**/

5、优化

关于如果存在嵌套的话，就如下例：

Student中又有Teacher类的引用

package pojo;import org.springframework.context.annotation.ComponentScan;
import org.springframework.stereotype.Component;@Component
public class Student {private String name;private Integer age;private Teacher teacher;public Student() {}public void setTeacher(Teacher teacher) {this.teacher = teacher;}public Student(String name, Integer age) {this.name = name;this.age = age;}public void setName(String name) {this.name = name;}public void setAge(Integer age) {this.age = age;}@Overridepublic String toString() {return "Student{" +"name='" + name + '\'' +", age=" + age +", teacher=" + teacher +'}';}
}

对应的解决方法

1、

<?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="pojo.Student"><property name="name" value="mike"/><property name="age" value="12"/><property name="teacher"><bean class="pojo.Teacher"><property name="age" value="55"/><property name="name" value="john"/></bean></property></bean>
</beans>

2、

<?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="teacher1" class="pojo.Teacher"><property name="name" value="john"/><property name="age" value="55"/></bean><bean id="student" class="pojo.Student"><property name="name" value="mike"/><property name="age" value="12"/><property name="teacher" ref="teacher1"/></bean></beans>

测试

@Test
public void test2(){ApplicationContext context = new ClassPathXmlApplicationContext("bean.xml");Student student = context.getBean("student", Student.class);System.out.println(student);
}
/**
output:  Student{name='mike', age=12, teacher=Teacher{name='john', age=55}}
**/