Spring @Value无法获取系统属性

Question

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

public class PropertyReader {
    @Value("${spring.active.profiles")
    private String profile;

    @Nonnull
    public String getProfile() {
        return profile;
    }
}

and this is test I have

public class PropertyReaderTest {

    @Test
    public void testGetProfile() throws Exception {
        System.out.printf(System.getProperty("spring.active.profiles"));
        assertEquals("development", new PropertyReader().getProfile());
    }
}

and the dependency I have is

<dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>4.0.3.RELEASE</version>
        </dependency>
    </dependencies>

and I see

development
java.lang.AssertionError: 
Expected :development
Actual   :null

Answer 1

first thing i am assuming your syntax is correct and its type mistake for @value that you have posted.

 @Value("${spring.active.profiles}")

Now to use @value, you must make the class register as a spring bean and that too using only annotation. even if you register class using xml also your @value will not work.

and also get the bean using spring container to happen automatic injection, dont create object by yourselves using new.

Solution to your above problem

1)

@Component
PropertyReader 

make class PropertyReader as a spring bean using @Component.

2)load bean from application context in your test class, dont use new to create it.

Answer 2

Yuo应该将@Service放在PropertyReader类上，或者您应该使用XML spring文件来定义bean并让spring来实现属性的价位化