Spring注解--@Value、@PropertySource-蒲公英云

Spring注解--@Value、@PropertySource

Bean

package pers.zhang.bean;
import org.springframework.beans.factory.annotation.Value;
public class Person { 
    //使用@Value赋值
    //1. 基本数值
    //2. SpEL： #{}
    //3. ${}：取出配置文件中的值(在运行环境中的值)
    @Value("张三")
    private String name;
    @Value("#{20 - 2}")
    private Integer age;
    @Value("${person.nickName}")
    private String nickName;
    public String getNickName() { 
        return nickName;
    }
    public void setNickName(String nickName) { 
        this.nickName = nickName;
    }
    public Person() { 
    }
    public Person(String name, Integer age) { 
        this.name = name;
        this.age = age;
    }
    public String getName() { 
        return name;
    }
    public void setName(String name) { 
        this.name = name;
    }
    public Integer getAge() { 
        return age;
    }
    public void setAge(Integer age) { 
        this.age = age;
    }
    @Override
    public String toString() { 
        return "Person{" +
                "name='" + name + '\'' +
                ", age=" + age +
                ", nickName='" + nickName + '\'' +
                '}';
    }
}

主配置文件

package pers.zhang.config;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;
import org.springframework.context.annotation.PropertySources;
import pers.zhang.bean.Person;
//加载外部配置文件保存到运行的环境变量中，参数为String[]
@PropertySource(value = { "classpath:/person.properties"})
//一次指定多个PropertySource
//@PropertySources()
@Configuration
public class MainConfigOfPropertyValues { 
    @Bean
    public Person person(){ 
        return new Person();
    }
}

配置文件:

person.nickName=nikie

测试：

@Test
    public void test01(){ 
        AnnotationConfigApplicationContext ac = new AnnotationConfigApplicationContext(MainConfigOfPropertyValues.class);
        String[] names = ac.getBeanDefinitionNames();
        for(String name : names){ 
            System.out.println(name);
        }
        System.out.println("****************************************");
        Person person = (Person) ac.getBean("person");
        System.out.println(person);
        System.out.println("****************************************");
        //通过环境变量获取配置文件中的值
        String s = ac.getEnvironment().getProperty("person.nickName");
        System.out.println(s);
    }

输出:

org.springframework.context.annotation.internalConfigurationAnnotationProcessor
org.springframework.context.annotation.internalAutowiredAnnotationProcessor
org.springframework.context.annotation.internalRequiredAnnotationProcessor
org.springframework.context.annotation.internalCommonAnnotationProcessor
org.springframework.context.event.internalEventListenerProcessor
org.springframework.context.event.internalEventListenerFactory
mainConfigOfPropertyValues
person
****************************************
Person{ name='张三', age=18, nickName='nikie'}
****************************************
nikie