<dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>5.3.13</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>
    </dependencies>

package com.example.pojo;

public class Student {
    private int id;
    private String name;
    private String address;

    public Student(int id, String name, String address) {
        this.id = id;
        this.name = name;
        this.address = address;
    }

    public Student(){}

    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;
    }

    public String getAddress() {
        return address;
    }

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

    @Override
    public String toString() {
        return "Student[ " +
                "id=" + id +
                ", name='" + name + '\'' +
                ", address='" + address + '\'' +
                " ]";
    }
}

package com.example.dao;

import com.example.pojo.Student;

public interface StudentDao {
    // 根据id查询学生
    Student findById(int id);
}

package com.example.dao;

import com.example.pojo.Student;

public class StudentDaoImpl1 implements StudentDao{

    public StudentDaoImpl1() {
    }

    public StudentDaoImpl1(int a){};
    @Override
    public Student findById(int id){
        return new Student(id,"程序员","北京");
    }
}

<?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"
            default-autowire="constructor">
    <bean id="studentDao" class="com.example.dao.StudentDaoImpl1"/>
</beans>

package com.example;

import com.example.dao.StudentDao;
import com.example.service.StudentService;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.context.support.FileSystemXmlApplicationContext;

public class TestContainer {
    @Test
    public void t1(){
        // 创建Spring容器
        ApplicationContext ac = new ClassPathXmlApplicationContext("bean.xml");

        // 从容器中获取对象
        StudentDao studentDao1 = ac.getBean("studentDao",StudentDao.class);
        StudentDao studentDao2 = ac.getBean("studentDao",StudentDao.class);

        System.out.println(studentDao1.hashCode());
        System.out.println(studentDao2.hashCode());
        System.out.println(studentDao1.findById(1));
    }
}

    @Test
    public void t2(){
        // 创建spring容器
        ApplicationContext ac = new FileSystemXmlApplicationContext("C:\\JavaProjects\\06SSM_Projects\\springdemo\\spring_ioc1\\src\\main\\resources\\bean.xml");

        // 从容器中获取对象
        StudentDao userDao = ac.getBean("studentDao",StudentDao.class);
        System.out.println(userDao);
        System.out.println(userDao.findById(1));;
    }