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Copy a fileTag(s): IO


[Java 7]
import static java.nio.file.StandardCopyOption.*;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;

public class Test {
  public static void main(String[] args) throws IOException {
    Path source = Paths.get("c:/temp/0multipage.tif");
    Path target = Paths.get("c:/temp/1multipage.tif");
    Files.copy(source, target, REPLACE_EXISTING); // Files.move(...) is also possible
    // see http://docs.oracle.com/javase/tutorial/essential/io/copy.html
  }
}

[JDK1.4 using the java.nio package]

import java.io.*;
import java.nio.channels.*;

public class FileUtils{
    public static void copyFile(File in, File out)
        throws IOException
    {
        FileChannel inChannel = new
            FileInputStream(in).getChannel();
        FileChannel outChannel = new
            FileOutputStream(out).getChannel();
        try {
            inChannel.transferTo(0, inChannel.size(),
                    outChannel);
        }
        catch (IOException e) {
            throw e;
        }
        finally {
            if (inChannel != null) inChannel.close();
            if (outChannel != null) outChannel.close();
        }
    }

    public static void main(String args[]) throws IOException{
        FileUtils.copyFile(new File(args[0]),new File(args[1]));
  }
}
NOTE:
In win2000 , the transferTo() does not transfer files > than 2^31-1 bytes. it throws an exception of "java.io.IOException: The parameter is incorrect"
In solaris8 , Bytes transfered to Target channel are 2^31-1 even if the source channel file is greater than 2^31-1
In LinuxRH7.1 , it gives an error of java.io.IOException: Input/output error

ref : http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4643189

On the Windows plateform, you can't copy a file bigger than 64Mb, an Exception in thread "main" java.io.IOException: Insufficient system resources exist to complete the requested service is thrown.

For a discussion about this see : http://forum.java.sun.com/thread.jspa?threadID=439695&messageID=2917510

The workaround is to copy in a loop 64Mb each time until there is no more data.

Replace

        ...
        try {
            inChannel.transferTo(0, inChannel.size(),
                    outChannel);
        }
        ...
by
        ...
        try {
           // magic number for Windows, 64Mb - 32Kb)
           int maxCount = (64 * 1024 * 1024) - (32 * 1024);
           long size = inChannel.size();
           long position = 0;
           while (position < size) {
              position +=
                inChannel.transferTo(position, maxCount, outChannel);
        }
        ...

[Old technique (pre JDK1.4)]
import java.io.*;

public class FileUtils{
  public static void copyFile(File in, File out) throws Exception {
    FileInputStream fis  = new FileInputStream(in);
    FileOutputStream fos = new FileOutputStream(out);
    try {
        byte[] buf = new byte[1024];
        int i = 0;
        while ((i = fis.read(buf)) != -1) {
            fos.write(buf, 0, i);
        }
    }
    catch (Exception e) {
        throw e;
    }
    finally {
        if (fis != null) fis.close();
        if (fos != null) fos.close();
    }
  }

  public static void main(String args[]) throws Exception{
    FileUtils.copyFile(new File(args[0]),new File(args[1]));
  }
}

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