Utility methods for handling streams : Stream « File Input Output « Java

1. Java
2. File Input Output
3. Stream

Utility methods for handling streams

    
//The contents of this file are subject to the Mozilla Public License Version 1.1
//(the "License"); you may not use this file except in compliance with the 
//License. You may obtain a copy of the License at http://www.mozilla.org/MPL/
//
//Software distributed under the License is distributed on an "AS IS" basis,
//WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License 
//for the specific language governing rights and
//limitations under the License.
//
//The Original Code is "The Columba Project"
//
//The Initial Developers of the Original Code are Frederik Dietz and Timo Stich.
//Portions created by Frederik Dietz and Timo Stich are Copyright (C) 2003. 
//
//All Rights Reserved.


import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

/**
 * Contains utility methods for handling streams.
 */
public class StreamUtils {
  private static final int BUFFERSIZE = 8000;

  /**
   * Copies length bytes from an InputStream to an OutputStream.
   * 
   * @param in
   *            InputStream from wihch the bytes are to copied.
   * @param out
   *            OutputStream in which the bytes are copied.
   * @param length
   *            The number of bytes to copy
   * @return Number of bytes which are copied.
   * @throws IOException
   *             If the streams are unavailable.
   */
  public static int streamCopy(InputStream in, OutputStream out, int length)
      throws IOException {
    byte[] buffer = new byte[BUFFERSIZE];
    int read;
    int copied = 0;

    while ((read = in
        .read(buffer, 0, Math.min(BUFFERSIZE, length - copied))) > 0) {
      out.write(buffer, 0, read);
      copied += read;
    }

    return copied;
  }

  /**
   * Copies all bytes from an InputStream to an OutputStream. The buffer size
   * is set to 8000 bytes.
   * 
   * @param _isInput
   *            InputStream from wihch the bytes are to copied.
   * @param _osOutput
   *            OutputStream in which the bytes are copied.
   * @return Number of bytes which are copied.
   * @throws IOException
   *             If the Streams are unavailable.
   */
  public static long streamCopy(InputStream in, OutputStream out)
      throws IOException {
    byte[] buffer = new byte[BUFFERSIZE];
    int read;
    long copied = 0;

    while ((read = in.read(buffer)) > 0) {
      out.write(buffer, 0, read);
      copied += read;
    }

    return copied;
  }

  /**
   * Reads a InputStream of chars into a StringBuffer.
   * 
   * @param in
   *            the InputStream to read from
   * @return the interpreted InputStream
   * @throws IOException
   */
  public static StringBuffer readCharacterStream(InputStream in)
      throws IOException {
    StringBuffer result = new StringBuffer(in.available());
    int read = in.read();

    while (read > 0) {
      result.append((char) read);
      read = in.read();
    }

    in.close();

    return result;
  }

  public static byte[] readInByteArray(InputStream in) throws IOException {
    byte[] result = new byte[in.available()];

    in.read(result);

    in.close();

    return result;
  }

  /**
   * Copies all bytes from the given InputStream into an internal
   * ByteArrayOutputStream and returnes a new InputStream with all bytes from
   * the ByteArrayOutputStream. The data are real copied so this method
   * "clones" the given Inputstream and returns a new InputStream with same
   * data.
   * 
   * @param from
   *            InputStream from which all data are to copy
   * @return a new InputStream with all data from the given InputStream
   * @throws IOException
   */
  public static InputStream streamClone(InputStream from) throws IOException {
    ByteArrayOutputStream out = new ByteArrayOutputStream();
    streamCopy(from, out);

    return new ByteArrayInputStream(out.toByteArray());
  }
}

   
    
    
    
  

Related examples in the same category