在属性上使用@Value

  1. package com.chentianyu.ba01;
  3. import org.springframework.beans.factory.annotation.Value;
  4. import org.springframework.stereotype.Component;
  6. @Component("myStudent")
  7. public class Student {
  8.     /**
  9.      * @Value: 简单类型的属性赋值
  10.      * 属性: value 是String类型的，表示简单类型的属性值
  11.      * 位置: 1.在属性定义上面，无需set方法，推荐使用
  12.      *      2.在set方法的上面
  13.      */
  14.     @Value(value = "张三")
  15.     private String name;
  16.     @Value(value = "29")
  17.     private Integer age;
  19.     public String getName() {
  20.         return name;
  21.     }
  23.     /*public void setName(String name) {
  24.         this.name = name;
  25.     }*/
  27.     public Integer getAge() {
  28.         return age;
  29.     }
  31.     /*public void setAge(Integer age) {
  32.         this.age = age;
  33.     }*/
  35.     @Override
  36.     public String toString() {
  37.         return "Student{" +
  38.                 "name='" + name + '\'' +
  39.                 ", age=" + age +
  40.                 '}';
  41.     }
  42. }

测试类

  1. @Test
  2. public void test01(){
  3.     String config = "applicationContext.xml";
  4.     ApplicationContext applicationContext = new ClassPathXmlApplicationContext(config);
  5.     //从容器中获取对象(需要id(value里的就是id))
  6.     Student student = (Student) applicationContext.getBean("myStudent");
  7.     System.out.println(student);
  8. }
  1. Student{name='张三', age=29}

在set方法上使用@Value

package com.chentianyu.ba01;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

@Component("myStudent")
public class Student {
    /**
     * @Value: 简单类型的属性赋值
     * 属性: value 是String类型的，表示简单类型的属性值
     * 位置: 1.在属性定义上面，无需set方法，推荐使用
     *      2.在set方法的上面
     */
    private String name;
    private Integer age;

    public String getName() {
        return name;
    }

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

    public Integer getAge() {
        return age;
    }
    @Value("30")
    public void setAge(Integer age) {
        this.age = age;
    }

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

@Test
public void test01(){
    String config = "applicationContext.xml";
    ApplicationContext applicationContext = new ClassPathXmlApplicationContext(config);
    //从容器中获取对象(需要id(value里的就是id))
    Student student = (Student) applicationContext.getBean("myStudent");
    System.out.println(student);
}

Student{name='null', age=30}

getBean()底层是一个Map