void acquireReadLock() throws IOException {
  try {
    readLock.acquire();
  }
 catch (  InterruptedException e) {
    throw new IOException("Interrupted while waiting for read lock",e);
  }
}

void acquireReadLock ( ) throws IOException { try { readLock . acquire ( ) ; } catch ( InterruptedException e ) { throw new IOException ( "Interrupted while waiting for read lock" , e ) ; } }
try to acquire read lock on this connection and block until it is available .
