Wraps a stream, printing to standard out everything that is read from it. : Reader « File Input Output « Java

1. Java
2. File Input Output
3. Reader

Wraps a stream, printing to standard out everything that is read from it.

      
/*
 * LoggingWriter.java Created Sep 7, 2010 by Andrew Butler, PSL
 */
//package prisms.util;

import java.io.IOException;
import java.nio.CharBuffer;

/** Wraps a stream, printing to standard out everything that is read from it. */
public class LoggingReader extends java.io.Reader {
  private java.io.Reader theBase;

  private java.io.Writer theLog;

  /**
   * @param base
   *            The reader to wrap
   * @param file
   *            The name of the file to log to, or null to log to System.out
   * @throws IOException
   *             If an error occurs setting up the log file
   */
  public LoggingReader(java.io.Reader base, String file) throws IOException {
    theBase = base;
    if (file != null)
      theLog = new java.io.BufferedWriter(new java.io.FileWriter(file));
  }

  /**
   * @return The reader wrapped by this logging reader
   */
  public java.io.Reader getBase() {
    return theBase;
  }

  @Override
  public int read(CharBuffer target) throws IOException {
    int read = theBase.read(target);
    if (theLog != null)
      theLog.write(target.array(), 0, read);
    else
      System.out.print(target.toString().substring(0, read));
    return read;
  }

  @Override
  public int read() throws IOException {
    int read = theBase.read();
    if (read >= 0) {
      if (theLog != null)
        theLog.write(read);
      else
        System.out.print((char) read);
    }
    return read;
  }

  @Override
  public int read(char[] cbuf) throws IOException {
    int read = theBase.read(cbuf);
    if (theLog != null)
      theLog.write(cbuf, 0, read);
    else
      System.out.print(new String(cbuf, 0, read));
    return read;
  }

  @Override
  public int read(char[] cbuf, int off, int len) throws IOException {
    int read = theBase.read(cbuf, off, len);
    if (theLog != null)
      theLog.write(cbuf, off, read);
    else
      System.out.print(new String(cbuf, off, read));
    return read;
  }

  @Override
  public long skip(long n) throws IOException {
    return super.skip(n);
  }

  @Override
  public boolean ready() throws IOException {
    return theBase.ready();
  }

  @Override
  public boolean markSupported() {
    return false;
  }

  @Override
  public void close() throws java.io.IOException {
    if (theLog != null)
      theLog.close();
    else
      System.out.flush();
    theBase.close();
  }
}

   
    
    
    
    
    
  

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