java输入一个字符 进行判断

 public static void main (String[] args) throws IOException
   {
      char ch;
      BufferedReader buf =new BufferedReader(new InputStreamReader(System.in));
      System.out.println("请输入一个字符：");
      ch=(char)buf.read();
      if(ch<32)
         System.out.println("这是一个控制字符");
      else if(ch>='0'&&ch<='9')
         System.out.println("这是一个数字");
      else if(ch>='A'&&ch<='Z')
         System.out.println("这是一个大写字母");
      else if(ch>='a'&&ch<='z')
         System.out.println("这是一个小写字母");
      else
      System.out.println("这是其他字符");
   }

public static void main(String[] args)
    {
        Scanner sc = new Scanner(System.in);
        char a = sc.next().charAt(0);
        if(a>='A'&&a<='Z'){
            System.out.println("大写字母");
        }else if(a>='a' && a<='z'){
            System.out.println("小写字母");
        }else if(a>='0'&&a<='9'){
            System.out.println("数字");
        }else{
            System.out.println("其他字符");
        }
    }

```java
public class test {
    public static void main(String[] args){
        Scanner s= new Scanner(System.in);
        System.out.println("please input:");
        String a=s.nextLine();
        char k=a.charAt(0);
        System.out.println(k);
        if(k<=57&&k>=48){
            System.out.println("数字");
        }else if(k>=65&&k<=90){
            System.out.println("大写");
        }else if(k>=97&&k<=122){
            System.out.println("小写");
        }else if(k>=19968&&k<=40869){
            System.out.println("汉字");
        }else{
            System.out.println("其他");
        }

    }

}

```