springboot加载application.yml文件null

• 话不多说，直接上代码
• 本人项目为maven项目
• 以下是项目结构
• 
• pom.xml文件

• <?xml version="1.0" encoding="UTF-8"?>
  <project xmlns="http://maven.apache.org/POM/4.0.0"
           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
           xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
      <modelVersion>4.0.0</modelVersion>
      <parent>
          <groupId>org.springframework.boot</groupId>
          <artifactId>spring-boot-starter-parent</artifactId>
          <version>2.1.4.RELEASE</version>
          <relativePath/> <!-- lookup parent from repository -->
      </parent>
      <groupId>testSpringBootApplication</groupId>
      <artifactId>testSpringBootApplication</artifactId>
      <version>1.0-SNAPSHOT</version>
  
      <properties>
          <java.version>1.8</java.version>
      </properties>
  
      <dependencies>
          <dependency>
              <groupId>org.springframework.boot</groupId>
              <artifactId>spring-boot-starter</artifactId>
          </dependency>
  
          <dependency>
              <groupId>org.springframework.boot</groupId>
              <artifactId>spring-boot-starter-test</artifactId>
              <scope>test</scope>
          </dependency>
          <dependency>
              <groupId>org.springframework.boot</groupId>
              <artifactId>spring-boot-starter-web</artifactId>
          </dependency>
          <!--导入配置文件处理器，配置文件进行绑定就会有提示-->
          <dependency>
              <groupId>org.springframework.boot</groupId>
              <artifactId>spring-boot-configuration-processor</artifactId>
              <optional>true</optional>
          </dependency>
      </dependencies>
  
      <build>
          <plugins>
              <plugin>
                  <groupId>org.springframework.boot</groupId>
                  <artifactId>spring-boot-maven-plugin</artifactId>
              </plugin>
          </plugins>
      </build>
  </project>

• 配置文件：application.yml

  batch:
    buffer:
       size: 100
       max: 60
       sleep: 10
    excute:
        pool: 50

• 写一个对应次配置文件的类

• @Component
  public class BatchConfig {
      @Value("${batch.buffer.size}")
      public String buffer_size;
      @Value("${batch.excute.pool}")
      public String excute_pool;
      @Value("${batch.buffer.max}")
      public String buffer_max;
      @Value("${batch.buffer.sleep}")
      public String buffer_sleep;
  }

• 因为使用注解autowired一直创建对象失败，所以只能写一个静态类来自动加载BatchConfig

• @Component
  public class StaticConfig {
      public static BatchConfig batchConfigstatic;
      @Autowired
      private BatchConfig batchConfig;
      @PostConstruct
      public void initStaticDao() {
          batchConfigstatic = this.batchConfig;
      }
  }

• service层调用配置文件

• @Service
  public class TestService {
      private String buffermax;
      public TestService() {
          buffermax = StaticConfig.batchConfigstatic.buffer_max;
          System.out.println("size="+buffermax);
      }
  }

• 启动类

• @SpringBootApplication
  @EnableConfigurationProperties
  @EnableAutoConfiguration
  @ComponentScan("com.hywc")
  public class Application {
      public static void main(String[] args) {
          // 启动springboot
          //ApplicationContext applicationContext =
          SpringApplication.run(Application.class, args);
      }
  }

• 运行结果
• 
• 因之前@Value以及@ConfigurationProperties形式均为null，所以中间加了一层，亲测可用，哈哈！！！

原文地址：https://www.cnblogs.com/lxyuuuuu/p/10949960.html