Copy and move files in Java, explanation and comparison of different approaches

Question

I implement a file manipulation functionality, and I paid attention that Java provides multiple techniques to copy and move files. Below you can find code snippets, briefly desc

Answer 1

It is already discussed enough here and the following is from here

Your first approach is File rename that has nothing to do with File copy

java.io.File class doesn’t have any shortcut method to copy file from source to destination.

1. Using Stream: This is the conventional way of file copy in java, here we create two Files, source and destination. Then we create InputStream from source and write it to destination file using OutputStream.

2. Using java.nio.channels.FileChannel: Java NIO classes were introduced in Java 1.4 and FileChannel can be used to copy file in java. According to transferFrom() method javadoc, this way of copy file is supposed to be faster than using Streams to copy files.

3. Using Apache Commons IO: Apache Commons IO FileUtils.copyFile(File srcFile, File destFile) can be used to copy file in java. If you are already using Apache Commons IO in your project, it makes sense to use this for code simplicity. Internally it uses Java NIO FileChannel, so you can avoid this wrapper method if you are not already using it for other functions.

4. Java 7 Files class: If you are working on Java 7, you can use Files class copy() method to copy file in java. It uses File System providers to copy the files.

Now to see which one of these methods is more efficient we will copy a large file[1 GB] using each one of them in a simple program. To avoid any performance speedups from caching we are going to use four different source files and four different destination files.{Refer code in link}

Time taken by FileStreams Copy = 127572360
Time taken by FileChannels Copy = 10449963
Time taken by Java7 Files Copy = 10808333
Time taken by Apache Commons IO Copy = 17971677

From the output it’s clear that Stream Copy is the best way to copy File in Java. FileChannels is the best way to copy large files. If you work with even larger files you will notice a much bigger speed difference