Spring Boot静态变量@Value的坑

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

@Component    
public class TUtil {    
    // 能获取值
    @Value("${spring.datasource.username}")
    private String username;
    
    // 加上static 不能获取值
    @Value("${spring.datasource.username}")
    private static String username;
    
    // 若想给静态变量赋值，可以在set方法上写@Value
    // spring.datasource.username的值会赋值到url上
    private static String url;
    
    @Value("${spring.datasource.username}")
    public void setUrl(String url) {
        this.url = url;
    }
}