Here's an example Java program to check whether a given character is a vowel or a consonant: 

import java.util.Scanner;

public class VowelOrConsonant {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        System.out.print("Enter a character: ");
        char ch = scanner.next().charAt(0);

        if (ch == 'a' || ch == 'e' || ch == 'i' || ch == 'o' || ch == 'u' ||
            ch == 'A' || ch == 'E' || ch == 'I' || ch == 'O' || ch == 'U') {
            System.out.println(ch + " is a vowel");
        } else {
            System.out.println(ch + " is a consonant");
        }
    }
}

In this program, we use a Scanner object to read a character from the user. We then check whether the character is one of the vowels ('a', 'e', 'i', 'o', 'u', 'A', 'E', 'I', 'O', 'U'). If it is, we print a message saying that the character is a vowel. Otherwise, we print a message saying that the character is a consonant. Note that we use the charAt() method to extract the first character from the user input.