isHex

public class Test {

    public static boolean isHex(String str) {
        boolean isHexFlg = true;

        int i = 0;
        char c;

        for (i = 0; i < str.length(); i++) {
            c = str.charAt(i);

            if ( !( ( (  c >= '0' ) && ( c <= '9' ) ) ||
                   ( (  c >= 'A' ) && ( c <= 'F' ) ) ||
                   (  c >= 'a' ) && ( c <= 'f' ) ) ) {
                isHexFlg = false;
            }
        }

        return isHexFlg;
    }

    /**
     * @param args
     */
    public static void main(String[] args) {

        boolean b = false;
        String str = "11111112222222aadd1232";

        b = isHex(str);
        if (b) {
            System.out.println(str + "是十六进制数");
        } else {
            System.out.println(str +"不是十六进制数");
        }
    }

}