Java I/O How to - Copy file with buffer

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Question

We would like to know how to copy file with buffer.

Answer

//  w ww.j a v  a  2 s.c o m
/** 
 * 
 * The ObjectStyle Group Software License, version 1.1
 * ObjectStyle Group - http://objectstyle.org/
 * 
 * Copyright (c) 2002-2005, Andrei (Andrus) Adamchik and individual authors
 * of the software. All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 
 * 3. The end-user documentation included with the redistribution, if any,
 *    must include the following acknowlegement:
 *    "This product includes software developed by independent contributors
 *    and hosted on ObjectStyle Group web site (http://objectstyle.org/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 * 
 * 4. The names "ObjectStyle Group" and "Cayenne" must not be used to endorse
 *    or promote products derived from this software without prior written
 *    permission. For written permission, email
 *    "andrus at objectstyle dot org".
 * 
 * 5. Products derived from this software may not be called "ObjectStyle"
 *    or "Cayenne", nor may "ObjectStyle" or "Cayenne" appear in their
 *    names without prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE OBJECTSTYLE GROUP OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * 
 * 
 * This software consists of voluntary contributions made by many
 * individuals and hosted on ObjectStyle Group web site.  For more
 * information on the ObjectStyle Group, please see
 * <http://objectstyle.org/>.
 */

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URL;

/**
 * Contains various unorganized static utility methods used across Cayenne.
 * 
 * @author Andrei Adamchik
 */
public class Main {

  /**
   * Copies file contents from source to destination. Makes up for the lack of
   * file copying utilities in Java
   */
  public static boolean copy(File source, File destination) {
    BufferedInputStream fin = null;
    BufferedOutputStream fout = null;
    try {
      int bufSize = 8 * 1024;
      fin = new BufferedInputStream(new FileInputStream(source), bufSize);
      fout = new BufferedOutputStream(new FileOutputStream(destination),
          bufSize);
      copyPipe(fin, fout, bufSize);
    } catch (IOException ioex) {
      return false;
    } catch (SecurityException sx) {
      return false;
    } finally {
      if (fin != null) {
        try {
          fin.close();
        } catch (IOException cioex) {
        }
      }
      if (fout != null) {
        try {
          fout.close();
        } catch (IOException cioex) {
        }
      }
    }
    return true;
  }

  /**
   * Save URL contents to a file.
   */
  public static boolean copy(URL from, File to) {
    BufferedInputStream urlin = null;
    BufferedOutputStream fout = null;
    try {
      int bufSize = 8 * 1024;
      urlin = new BufferedInputStream(from.openConnection().getInputStream(),
          bufSize);
      fout = new BufferedOutputStream(new FileOutputStream(to), bufSize);
      copyPipe(urlin, fout, bufSize);
    } catch (IOException ioex) {
      return false;
    } catch (SecurityException sx) {
      return false;
    } finally {
      if (urlin != null) {
        try {
          urlin.close();
        } catch (IOException cioex) {
        }
      }
      if (fout != null) {
        try {
          fout.close();
        } catch (IOException cioex) {
        }
      }
    }
    return true;
  }

  /**
   * Reads data from the input and writes it to the output, until the end of the
   * input stream.
   * 
   * @param in
   * @param out
   * @param bufSizeHint
   * @throws IOException
   */
  public static void copyPipe(InputStream in, OutputStream out, int bufSizeHint)
      throws IOException {
    int read = -1;
    byte[] buf = new byte[bufSizeHint];
    while ((read = in.read(buf, 0, bufSizeHint)) >= 0) {
      out.write(buf, 0, read);
    }
    out.flush();
  }

}

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