SpringBoot设置@Value注解获取不到值

private static String tagValue; //错误
private final String tagValue; //错误

@Component //遗漏
class TestValue{
	@Value("${tag}")
	private String tagValue;
}

@Component
class TestValue{
	@Value("${tag}")
	private String tagValue;
}

class Test{
	...
	TestValue testValue = new TestValue()
}

class Test{
	@AutoWired
	TestValue testValue;
	public void aa(){
		testValue.test();
	}
}