Spring中的@ConfigurationProperties在方法上的使用详解

// targer：可作用在类、方法上
@Target({ ElementType.TYPE, ElementType.METHOD })
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface ConfigurationProperties {
}

@Component
@ConfigurationProperties(prefix = "test.config")
@Setter
@ToString
public class TestConfigDemo {
    private String username;
    private String pwd;
}
// yml
test:
  config:
    username: test-config-username
    pwd: test-config-pwd
// 测试代码
@Component
public class TestConfigAppRunner implements ApplicationRunner {
    @Autowired
    TestConfigDemo testConfigDemo;
    @Override
    public void run(ApplicationArguments args) throws Exception {
        System.out.println(testConfigDemo);
    }
}

// 该配置类上 无 任何spring的注解
@Setter
@ToString
public class TestConfigDemo {
    private String username;
    private String pwd;
}

// 准备个@Configuration 配置类
@Configuration
public class ConfigurationDemo {
	// 这里将TestConfigDemo 配置类 生成bean对象
    // 此时：TestConfigDemo里面的属性将与配置文件yml内容进行绑定
    @Bean
    @ConfigurationProperties(prefix = "test.config")
    public TestConfigDemo testConfigDemo(){
        return new TestConfigDemo();
    }
}

@Component
public class TestConfigAppRunner implements ApplicationRunner {

    @Autowired
    TestConfigDemo testConfigDemo;

    @Override
    public void run(ApplicationArguments args) throws Exception {
        System.out.println(testConfigDemo);
    }
}