java explain the configuration of the spring

First, the directory structure is as follows:

1. User.java

 1 package cn.sxt.vo;
 2 
 3 import java.util.Date;
 4 
 5 public class User {
 6     
 7     private String name;
 8     private int age;
 9     private Date birthday;
10     public String getName() {
11         return name;
12     }
13     public void setName(String name) {
14         this.name = name;
15     }
16     public int getAge() {
17         return age;
18     }
19     public void setAge(int age) {
20         this.age = age;
21     }
22     public Date getBirthday() {
23         return birthday;
24     }
25     public void setBirthday(Date birthday) {
26         this.birthday = birthday;
27     }
28     @Override
29     public String toString() {
30         return "User [name=" + name + ", age=" + age + ", birthday=" + birthday + "]";
31     }
32 }

2. beans.xml

<? XML Version = "1.0" encoding = "UTF-. 8"?> 
<Beans xmlns = "http://www.springframework.org/schema/beans" 
    xmlns: the 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 "> 
      <-!  
          import for importing major role in other configuration information is developed using teamwork
        -> 
      < import Resource = " context.xml " /> 
</ Beans>

3. context.xml

<? XML Version = "1.0" encoding = "UTF-. 8"?> 
<Beans xmlns = "http://www.springframework.org/schema/beans" 
    xmlns: the xsi = "http://www.w3.org / 2001 / the XMLSchema-instance " 
    the xsi: the schemaLocation =" http://www.springframework.org/schema/beans 
        HTTP: // www.springframework.org/schema/beans/spring-beans.xsd "> 
    < description > 
        description information
     </ Description> 
    <-!  
        the bean represents java object   id is the identifier of the object only in the container . You may be acquired by the object identifier from the container .
        If no name id configured, then the name will serve as the identifier of the object , if the configuration of the id, the id is an alias .
        Simultaneously may be provided a plurality of aliases, a separator (a comma, a space between the plurality of aliases,
        Where the fully qualified class name = name + packet class name;
      -> 
    < the bean  ID = "User" name = "U1, U2 U3; U4" class = "cn.sxt.vo.User"> 
        <-! Property represents a property of the class, set the need to provide a method to set the value to an object .
              name is a set method after removing the set 
              value of the set value of the attribute, value and the basic data types may be provided to the String attribute .
              If the value is a need to use an object reference ref attribute
          -> 
        < Property  name = "name" value = "Joe Smith crazy" /> 
        <Property name = "Age" value = "22 is" /> 
    </ the bean> 
    <!  
        
        
    <alias name="user" alias="u5"/>
</beans>

4. SpringTest.java

package cn.sxt.spring;

import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import cn.sxt.vo.User;

public class SpringTest {
    @Test
    public void testHello(){
        
        ApplicationContext ac = new ClassPathXmlApplicationContext("beans.xml");
        User u=(User)ac.getBean("u4");
        System.out.println(u);
    }
}