java判断字符串是否为数字、字母、汉字

public class ZhStringUtil {

/**
 * 判断字符串是否为数字
 * @param str
 * @return
 */
public static boolean isNumberic(String str) {
    Pattern pattern = Pattern.compile("[0-9]*");
    return pattern.matcher(str).matches();
}

/**
 * 判断一个字符串是否为字母
 * @param fstrData
 * @return
 */
public static boolean check(String fstrData) {
    char c = fstrData.charAt(0);
    if (((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z'))) {
        return true;
    } else {
        return false;
    }
}

/**
 * 判断是否为汉字
 * @param str
 * @return
 */
public static boolean vd(String str) {

    char[] chars = str.toCharArray();
    boolean isUtf8 = false;
    for (int i = 0; i < chars.length; i++) {
        byte[] bytes = ("" + chars[i]).getBytes();
        if (bytes.length == 2) {
            int[] ints = new int[2];
            ints[0] = bytes[0] & 0xff;
            ints[1] = bytes[1] & 0xff;

            if (ints[0] >= 0x81 && ints[0] <= 0xFE && ints[1] >= 0x40 && ints[1] <= 0xFE) {
                isUtf8 = true;
                break;
            }
        }
    }
    return isUtf8;
}

}