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2010-06-01T06:47:15Z

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в 18:01, 31 мая 2010

2010-05-31T18:01:45Z

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== Close stream in finally ==



<source lang="java">

/*
* Copyright (c) 2004 David Flanagan. All rights reserved.
* This code is from the book Java Examples in a Nutshell, 3nd Edition.
* It is provided AS-IS, WITHOUT ANY WARRANTY either expressed or implied.
* You may study, use, and modify it for any non-commercial purpose,
* including teaching and use in open-source projects.
* You may distribute it non-commercially as long as you retain this notice.
* For a commercial use license, or to purchase the book,
* please visit http://www.davidflanagan.ru/javaexamples3.
*/
//package je3.nio;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.channels.Channels;
import java.nio.channels.FileChannel;
import java.nio.channels.WritableByteChannel;
/**
* FileCopy2.java: this program copies the file named in its first argument to
* the file named in its second argument, or to standard output if there is no
* second argument.
*/
public class FileCopy2 {
public static void main(String[] args) {
FileInputStream fin = null; // Streams to the two files.
FileOutputStream fout = null; // These are closed in the finally block.
try {
// Open a stream to for the input file and get a channel from it
fin = new FileInputStream(args[0]);
FileChannel in = fin.getChannel();
// Now get the output channel
WritableByteChannel out;
if (args.length > 1) { // If there is a second filename
fout = new FileOutputStream(args[1]); // open file stream
out = fout.getChannel(); // get its channel
} else { // There is no destination filename
out = Channels.newChannel(System.out); // wrap stdout stream
}
// Query the size of the input file
long numbytes = in.size();
// Bulk-transfer all bytes from one channel to the other.
// This is a special feature of FileChannel channels.
// See also FileChannel.transferFrom()
in.transferTo(0, numbytes, out);
} catch (IOException e) {
// IOExceptions usually have useful informative messages.
// Display the message if anything goes wrong.
System.out.println(e);
} finally {
// Always close input and output streams. Doing this closes
// the channels associated with them as well.
try {
if (fin != null)
fin.close();
if (fout != null)
fout.close();
} catch (IOException e) {
}
}
}
}
</source>



== Test case for finally, to show its effect with return or exit ==



<source lang="java">

/*
* Copyright (c) Ian F. Darwin, http://www.darwinsys.ru/, 1996-2002.
* All rights reserved. Software written by Ian F. Darwin and others.
* $Id: LICENSE,v 1.8 2004/02/09 03:33:38 ian Exp $
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS""
* AND ANY EXPRESS 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 AUTHOR OR 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.
*
* Java, the Duke mascot, and all variants of Sun"s Java "steaming coffee
* cup" logo are trademarks of Sun Microsystems. Sun"s, and James Gosling"s,
* pioneering role in inventing and promulgating (and standardizing) the Java
* language and environment is gratefully acknowledged.
*
* The pioneering role of Dennis Ritchie and Bjarne Stroustrup, of AT&T, for
* inventing predecessor languages C and C++ is also gratefully acknowledged.
*/

/** Test case for "finally", to show its effect with
* return or exit.
*/
public class Finally {
/** Main method, does the work of the testing... */
public static void main(String[] argv) {
try {
throw new Exception();
} catch (Exception e) {
System.out.println("Caught Exception");
return; // with return, Goodbye appears
// System.exit(1); // with exit, Goodbye does not appear
} finally {
System.out.println("Goodbye!");
}
}
}

</source>

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Admin: 1 версия

в 18:01, 31 мая 2010