StreamConsumer.java

/*
 * StreamConsumer.java
 *
 * Created on Aug 31, 2011, 11:03:18 AM
 *
 * Description: Provides a stream consumer that logs its consumed stream.
 *
 * Copyright (C) Aug 31, 2011, Stephen L. Reed, Texai.org.
 *
 */
package org.texai.util;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import net.jcip.annotations.NotThreadSafe;
import org.apache.log4j.Logger;

/** Provides a stream consumer that logs its consumed stream.
 *
 * @author reed
 */
@NotThreadSafe
public class StreamConsumer extends Thread {

  /** the input stream that consumes the graph program standard output stream */
  private final InputStream inputStream;
  /** the logger */
  private final Logger logger;

  /** Constructs a new StreamConsumer instance.
   *
   * @param inputStream the input stream
   * @param logger the logger
   */
  public StreamConsumer(
          final InputStream inputStream,
          final Logger logger) {
    //Preconditions
    assert inputStream != null : "inputStream must not be null";
    assert logger != null : "logger must not be null";

    this.inputStream = inputStream;
    this.logger = logger;
  }

  /** Runs this stream consumer. */
  @Override
  public void run() {
    try {
      final BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
      @SuppressWarnings("UnusedAssignment")
      String line = null;
      while ((line = bufferedReader.readLine()) != null) {
        logger.info(">" + line);
        if (logger.isDebugEnabled()) {
          logger.debug(">" + line);
        }
      }
    } catch (IOException ioe) {
      if (logger.isDebugEnabled()) {
        logger.debug(ioe.getMessage());
      }
    }
  }
}