package org.codehaus.plexus.util.cli;
   
   import java.io.BufferedReader;
   import java.io.IOException;
   import java.io.InputStream;
   import java.io.InputStreamReader;
   import java.io.PrintWriter;
   
   import org.codehaus.plexus.util.IOUtil;
  
  /**
   * Class to pump the error stream during Process's runtime. Copied from the Ant built-in task.
   */
  public class StreamPumper extends AbstractStreamHandler {
  
  	private final BufferedReader in;
  	private final StreamConsumer consumer;
  	private final PrintWriter out;
  	private volatile Exception exception = null;
  	private static final int SIZE = 1024;
  
  	public StreamPumper(InputStream in) {
  		this(in, (StreamConsumer) null);
  	}
  
  	public StreamPumper(InputStream in, StreamConsumer consumer) {
  		this(in, null, consumer);
  	}
  
  	public StreamPumper(InputStream in, PrintWriter writer) {
  		this(in, writer, null);
  	}
  
  	public StreamPumper(InputStream in, PrintWriter writer, StreamConsumer consumer) {
  		this.in = new BufferedReader(new InputStreamReader(in), SIZE);
  		this.out = writer;
  		this.consumer = consumer;
  	}
  
  	@Override
  	public void run() {
  		try {
  			for (String line = in.readLine(); line != null; line = in.readLine()) {
  				try {
  					if (exception == null) {
  						consumeLine(line);
  					}
  				} catch (Exception t) {
  					exception = t;
  				}
  
  				if (out != null) {
  					out.println(line);
  					out.flush();
  				}
  			}
  		} catch (IOException e) {
  			exception = e;
  		} finally {
  			IOUtil.close(in);
  			synchronized (this) {
  				setDone();
  				this.notifyAll();
  			}
  		}
  	}
  
  	public void flush() {
  		if (out != null) {
  			out.flush();
  		}
  	}
  
  	public void close() {
  		IOUtil.close(out);
  	}
  
  	public Exception getException() {
  		return exception;
  	}
  
  	private void consumeLine(String line) {
  		if (consumer != null && !isDisabled()) {
  			consumer.consumeLine(line);
  		}
  	}
  }