Spring Boot读取yml或properties配置文件中的属性值

@Component
@ConfigurationProperties(prefix = "comment")
public class Comment {
	private String avatar;
}

comment:
  avatar: /images/avatar.png

pom.xml中加上这个包，否则@ConfigurationProperties不起作用

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-configuration-processor</artifactId>
            <version>2.2.2.RELEASE</version>
        </dependency>

单元测试：
注意：
1.import org.junit.Test; 是这个包，而不是 import org.junit.jupiter.api.Test;
2.
@RunWith(SpringRunner.class)
@SpringBootTest(classes = BlogApplication.class)
是启动springboot的，加了这个才能用@Autowired

@RunWith(SpringRunner.class)
@SpringBootTest(classes = BlogApplication.class)
public class Tests {


	@Autowired
	private Comment comment;

	@Test
	public void CommentTest(){
		System.out.println(comment);
		//Comment{id=null, nickname='null', email='null', content='null', avatar='/images/avatar.png', createTime=null}
	}