11、spring注解學習（屬性賦值）——@Value賦值

1、創建Person類

public class Person {

    private String name;
    private Integer age;
    public Person() {
        super();
    }
    public Person(String name, Integer age) {
        super();
        this.name = name;
        this.age = age;
    }
    public String getName() {
        return name;
    }
    public Integer getAge() {
        return age;
    }
    public void setName(String name) {
        this.name = name;
    }
    public void setAge(Integer age) {
        this.age = age;
    }
    @Override
    public String toString() {
        return "Person [name=" + name + ", age=" + age + "]";
    }
}

2、spring配置類中注入Person

/**
 * 測試bean的屬性賦值的配置
 */
@Configuration
public class MainConfigOfPropertyValue {
    
    @Bean("person")
    public Person person() {
        return new Person();
    }
}

3、創建測試方法測試

    @Test
    public void test01() {
        AnnotationConfigApplicationContext applicationContext = new AnnotationConfigApplicationContext(MainConfigOfPropertyValue.class);
        Object bean = applicationContext.getBean("person");
        System.out.println(bean);
    }

得到結果：

 

 4、此時我們利用@Value進行賦值，修改Person類

public class Person {
    
    /*
     * 使用@Value賦值：
     *     1、基本數值
     *     2、可以寫SpEl；#{}
     *     3、可以寫${}、取出配置文件中(例如properties文件)的值（運行環境變量里面的值）
     */ @Value("張三") private String name;
    @Value("#{20-2}") private Integer age;
    public Person() {
        super();
    }
    public Person(String name, Integer age) {
        super();
        this.name = name;
        this.age = age;
    }
    public String getName() {
        return name;
    }
    public Integer getAge() {
        return age;
    }
    public void setName(String name) {
        this.name = name;
    }
    public void setAge(Integer age) {
        this.age = age;
    }
    @Override
    public String toString() {
        return "Person [name=" + name + ", age=" + age + "]";
    }
}

再次運行測試方法得到：