实现字符串的首字母大写

@SuppressWarnings({"all"})
public class test {
    public static void main(String[] args) {

        FirstUpperCase("bYte dANCe");


    }
    public static void FirstUpperCase(String s){
        if(s == null || s.isEmpty() || s == " "){
            throw new RuntimeException("数据有误");
        }

        String[] s1 = s.split(" ");
        StringBuffer stringBuffer = new StringBuffer();

        for (String str:s1) {
            stringBuffer.append(Character.toUpperCase
                    (str.charAt(0))).append(str.substring(1).toLowerCase()).append(" ");

        }
        System.out.println(stringBuffer.toString());


    }
}