How to use

peek

method

in

org.postgresql.core.VisibleBufferedInputStream

/**
 * Receives a single character from the backend, without advancing the current protocol stream
 * position.
 *
 * @return the character received
 * @throws IOException if an I/O Error occurs
 */
public int peekChar() throws IOException {
 int c = pg_input.peek();
 if (c < 0) {
  throw new EOFException();
 }
 return c;
}

/**
 * Receives a single character from the backend, without
 * advancing the current protocol stream position.
 *
 * @return the character received
 * @exception IOException if an I/O Error occurs
 */
public int PeekChar() throws IOException
{
  int c = pg_input.peek();
  if (c < 0)
    throw new EOFException();
  return c;
}

/**
 * Check for pending backend messages without blocking. Might return false when there actually are
 * messages waiting, depending on the characteristics of the underlying socket. This is used to
 * detect asynchronous notifies from the backend, when available.
 *
 * @return true if there is a pending backend message
 * @throws IOException if something wrong happens
 */
public boolean hasMessagePending() throws IOException {
 if (pg_input.available() > 0) {
  return true;
 }
 // In certain cases, available returns 0, yet there are bytes
 int soTimeout = getNetworkTimeout();
 setNetworkTimeout(1);
 try {
  return pg_input.peek() != -1;
 } catch (SocketTimeoutException e) {
  return false;
 } finally {
  setNetworkTimeout(soTimeout);
 }
}

/**
 * Receives a single character from the backend, without
 * advancing the current protocol stream position.
 *
 * @return the character received
 * @exception IOException if an I/O Error occurs
 */
public int PeekChar() throws IOException
{
  int c = pg_input.peek();
  if (c < 0)
    throw new EOFException();
  return c;
}