public class PdfUtils {

  public static boolean checkIsPDF(byte[] data) {
    return checkPdfHeader(data) && checkPdfTerminator(data);
  }

  private static boolean checkPdfHeader(byte[] data) {
    if (data == null || data.length < 7)
      return false;
    return ((areEqual(data[0], 0x25) && // %
        areEqual(data[1], 0x50) && // P
        areEqual(data[2], 0x44) && // D
        areEqual(data[3], 0x46) && // F
        areEqual(data[4], 0x2D) && // -
        areEqual(data[5], 0x31) && // 1
        areEqual(data[6], 0x2E)    // .
    ));
  }

  private static boolean checkPdfTerminator(byte[] data) {
    return true; //@todo. Not implemented yet
  }

  public static boolean areEqual(long a, long b) {
    return (a == b);
  }
}