/**
 * 
 */
package uk.ac.vamsas.client.simpleclient;

import java.io.DataOutputStream;
import java.io.IOException;
import java.io.OutputStream;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * @author jimp
 *
 */
public class AppDataOutputStream extends DataOutputStream {
  private Log log = LogFactory.getLog(AppDataOutputStream.class);
  private boolean isOpen=true;
  /**
   * @param out
   */
  public AppDataOutputStream(OutputStream out) {
    super(out);
    isOpen=true;
  }
  /* (non-Javadoc)
   * @see java.io.DataOutputStream#flush()
   */
  public void flush() throws IOException {
    if (isOpen)
      super.flush();
    else
      log.warn("flush() called on closed AppDataOutputStream");
  }
  /* (non-Javadoc)
   * @see java.io.DataOutputStream#write(byte[], int, int)
   */
  public synchronized void write(byte[] b, int off, int len) throws IOException {
    if (isOpen) {
      super.write(b, off, len);
    } else {
      log.debug("write(b,off,len) called on closed AppDataOutputStream");
      throw new IOException("Attempt to write to closed AppDataOutputStream");
    }
  }
  /* (non-Javadoc)
   * @see java.io.DataOutputStream#write(int)
   */
  public synchronized void write(int b) throws IOException {
    if (isOpen) {
      super.write(b);
    } else {
      log.debug("write(b) called on closed AppDataOutputStream");
      throw new IOException("Attempt to write to closed AppDataOutputStream");
    }
  }
  /**
   * Sets an internal flag preventing further write operations 
   * to the AppData output stream and flushes any pending writes.
   * @see java.io.FilterOutputStream#close()
   */
  public void close() throws IOException {
    isOpen=false;
    super.flush();
    log.debug("AppDataOutputStream was closed.");
  }
  /* (non-Javadoc)
   * @see java.io.FilterOutputStream#write(byte[])
   */
  public void write(byte[] b) throws IOException {
    if (isOpen) {
      super.write(b);
    } else {
      log.debug("write(b[]) called on closed AppDataOutputStream");
      throw new IOException("Attempt to write to closed AppDataOutputStream");
    }
  }
  /**
   * @return true if stream is still Open.
   */
  public boolean isOpen() {
    return isOpen;
  }
  
}