spring源码 @Value赋值，属性信息是保存在运行环境变量里面简单示例

通过@Value读取属性的值

新建maven，pom如下

<dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> <version>5.0.6.RELEASE</version> </dependency> 新建bean

public class Bird { @Value("张三") private String name; @Value("#{23-1}") private Integer age; @Value("${bird.color}") private String color; public Bird() { } public Bird(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 "Bird{" + "name='" + name + '\'' + ", age=" + age + ", color='" + color + '\'' + '}'; } } 在resources新建test.perperties

bird.color=red 新建config配置类，并加载属性文件

@Configuration @PropertySource(value = {"classpath:/test.properties"}) public class DemoConfig { @Bean public Bird bird() { return new Bird(); } } 新建启动类

public class DemoApp { public static void main(String[] args){ AnnotationConfigApplicationContext app = new AnnotationConfigApplicationContext(DemoConfig.class); System.out.println("IOC容器初始化完成"); String[] names = app.getBeanDefinitionNames(); for (int i = 0; i < names.length; i++) { String name = names[i]; System.out.println(name); } Bird bean = (Bird)app.getBean("bird"); System.out.println(bean); //属性信息是保存在运行环境变量里面 ConfigurableEnvironment environment = app.getEnvironment(); String color = environment.getProperty("bird.color"); System.out.println("environment:"+color); app.close(); } } 输出结果：

IOC容器初始化完成 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 demoConfig bird Bird{name='张三', age=22, color='red'} red