copy Completely (InputStream input, OutputStream output) : Copy « File « Java Tutorial

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.nio.channels.FileChannel;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.    
 */

public class Main {
  public static void copyCompletely(InputStream input, OutputStream output) throws IOException {
    // if both are file streams, use channel IO
    if ((output instanceof FileOutputStream) && (input instanceof FileInputStream)) {
      try {
        FileChannel target = ((FileOutputStream) output).getChannel();
        FileChannel source = ((FileInputStream) input).getChannel();

        source.transferTo(0, Integer.MAX_VALUE, target);

        source.close();
        target.close();

        return;
      } catch (Exception e) { /* failover to byte stream version */
      }
    }

    byte[] buf = new byte[8192];
    while (true) {
      int length = input.read(buf);
      if (length < 0)
        break;
      output.write(buf, 0, length);
    }

    try {
      input.close();
    } catch (IOException ignore) {
    }
    try {
      output.close();
    } catch (IOException ignore) {
    }
  }

}

11.78.Copy
	11.78.1.	Copy the source file system structure into the supplied target location.
	11.78.2.	Buffered copying between source(InputStream, Reader, String and byte[]) and destinations (OutputStream, Writer, String and byte[]).
	11.78.3.	Copies all data from an input stream to an output stream.
	11.78.4.	Copies the contents of the Reader into the Writer, until the end of the stream has been reached.
	11.78.5.	Copy a directory and all of its contents.
	11.78.6.	Copy a file and user buffer
	11.78.7.	Copy chars from a Reader to a Writer.
	11.78.8.	copy Completely (InputStream input, OutputStream output)
	11.78.9.	copy Completely (Reader input, Writer output)
	11.78.10.	copy Completely(URI input, URI output)
	11.78.11.	Buffered copying
	11.78.12.	Copy file and directory