How to copy a folder and all its subfolders and files into another folder

Question

How can I copy a folder and all its subfolders and files into another folder?

lukastymo · Answer 1 · 2014-09-14T20:39:17.830

Choose what you like:

FileUtils from Apache Commons IO (the easiest and safest way)

Example with FileUtils:

File srcDir = new File("C:/Demo/source");
File destDir = new File("C:/Demo/target");
FileUtils.copyDirectory(srcDir, destDir);

Manually, example before Java 7 (CHANGE: close streams in the finally-block)
Manually, Java >=7

Example with AutoCloseable feature in Java 7:

public void copy(File sourceLocation, File targetLocation) throws IOException {
    if (sourceLocation.isDirectory()) {
        copyDirectory(sourceLocation, targetLocation);
    } else {
        copyFile(sourceLocation, targetLocation);
    }
}

private void copyDirectory(File source, File target) throws IOException {
    if (!target.exists()) {
        target.mkdir();
    }

    for (String f : source.list()) {
        copy(new File(source, f), new File(target, f));
    }
}

private void copyFile(File source, File target) throws IOException {        
    try (
            InputStream in = new FileInputStream(source);
            OutputStream out = new FileOutputStream(target)
    ) {
        byte[] buf = new byte[1024];
        int length;
        while ((length = in.read(buf)) > 0) {
            out.write(buf, 0, length);
        }
    }
}

This is working but if an exception happens you won't close the streams : you should add a try catch finally block. — Tim Autin, Sep 14 '14 at 18:41
The `copyFile` can be enhanced by using the `Files#copy` method (as it uses native hooks if available). — n247s, Jul 30 '18 at 14:47
There is an error. It is not working if I want to copy 1 file - because targeLocation should always be a folder, whereas in your code, it is always used as a file in copyFile. — Eugene Kartoyev, Aug 10 '18 at 01:31

score 21 · Accepted Answer · edited Jun 02 '16 at 13:35

21

Apache Commons IO can do the trick for you. Have a look at FileUtils.

edited Jun 02 '16 at 13:35

pdem

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answered Mar 20 '11 at 13:23

Yaba

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link is down. pls update – 4ndro1d Apr 25 '13 at 09:54
1

http://commons.apache.org/proper/commons-io/apidocs/org/apache/commons/io/FileUtils.html#copyFile%28java.io.File,%20java.io.File%29 – Raghunandan May 14 '13 at 05:21

score 2 · Answer 3 · answered Mar 20 '11 at 13:25

2

look at java.io.File for a bunch of functions.

you will iterate through the existing structure and mkdir, save etc to achieve deep copy.

answered Mar 20 '11 at 13:25

Randy

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score 0 · Answer 4 · answered Oct 19 '15 at 08:50

0

JAVA NIO will help to you to solve your problem. Please have a look on this http://tutorials.jenkov.com/java-nio/files.html#overwriting-existing-files.

answered Oct 19 '15 at 08:50

yk2

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How to copy a folder and all its subfolders and files into another folder

4 Answers4

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