當(dāng)Constants類中常量值越來越多的時(shí)候，為方便管理不同類型的常量值，可以有如下比較清楚的靜態(tài)內(nèi)部類寫法。

public class Constants {
    
    public static final class URL{
        
        public static final String BAIDU = "https://www.baidu.com";
        
        public static final String TENGXUN = "https://www.qq.com/";
        
    }
    
    public static final class NAME{
        
        public static final String CHINEY = "chiney";
        
        public static final String SHERRY = "sherry";
        
    }
    
    public static void main(String[] args) {
        
        String url = Constants.URL.BAIDU;
        
        String name = Constants.NAME.CHINEY;
        
        System.out.println(name + " is using " + url);
        
        
    }
    
    
    

}