Apache FileUtils Examples.

Apache FileUtils Examples.

General file manipulation utilities.

Facilities are provided in the following areas:

1      Writing to a file.

2      Reading from a file.

3   Make a directory including parent directories.

4   Copying files and directories.

5     Deleting files and directories.

6   Converting to and from a URL.

7      Listing files and directories by filter and extension.

8   Comparing file content.

9    File last changed date.

1    Calculating a checksum.

Maven Repository

                <dependency>

                                                <groupId>commons-io</groupId>

                                                <artifactId>commons-io</artifactId>

                                                <version>2.4</version>

                                </dependency>

Examples.

package swain.swain;

import java.io.File;

import java.io.IOException;

import java.util.ArrayList;

import java.util.Collection;

import org.apache.commons.io.FileUtils;

import org.apache.commons.io.LineIterator;

import org.apache.commons.io.filefilter.SuffixFileFilter;

public class ApacheFileUtilsExample {

    private static final String PATH = "C:\\appdata\\";

    public static void main(String[] args) throws IOException {

         String fileString = FileUtils.readFileToString(new File(PATH + "file1.txt"));

         System.out.println("Reading file content:" + fileString);

         String fileString2 = FileUtils.readFileToString(new File(PATH + "file2.txt"));

         System.out.println("Reading content:" + fileString2);

         File file1 = new File(PATH + "file1.txt");

         File file2 = new File(PATH + "file2.txt");

         System.out.println("Comparing file content: " + FileUtils.contentEquals(file1, file2));

         FileUtils.copyDirectory(FileUtils.getFile(PATH), FileUtils.getFile(PATH + "copiedNewPath\\"));

         FileUtils.copyDirectory(FileUtils.getFile(PATH), FileUtils.getFile(PATH + "copiedFilterPath\\"), new SuffixFileFilter(".txt"));

         for (File f : FileUtils.getFile(PATH + "copiedFilterPath\\").listFiles()) {

             System.out.println("Contents of copiedFilterPath: " + f.getName());

         }

         File copy = FileUtils.getFile(PATH + "test1.txt");

         FileUtils.copyFile(file1, copy);

         System.out.println("Comparing file content:: " + FileUtils.contentEquals(file1, copy));

         for (File file : FileUtils.getFile(PATH).listFiles()) {

             System.out.println("File Name: " + file.getName());

         }

         FileUtils.deleteDirectory(FileUtils.getFile(PATH + "copiedFilterPath\\"));

         for (File file : FileUtils.getFile(PATH).listFiles()) {

             System.out.println("Contents of PATH after deletion: " + file.getName());

         }

         // Directories

         System.out.println("Temp Dir: " + FileUtils.getTempDirectory().getAbsolutePath());

         System.out.println("User Dir: " + FileUtils.getUserDirectory().getAbsolutePath());

         // Line Iterator

         LineIterator iter = FileUtils.lineIterator(file1);

         while (iter.hasNext()) {

             System.out.println("cmpFile1 lines: " + iter.next());

         }

         // Directory size

         System.out.println("Size of dir: " + FileUtils.sizeOfDirectory(FileUtils.getFile(PATH)) + " bytes.");

         // Ways of writing lines to a file.

         File fileToWrite1 = FileUtils.getFile(PATH + "file1.txt");

         File fileToWrite2 = FileUtils.getFile(PATH + "file2.txt");

         Collection<String> lines = new ArrayList<String>();

         lines.add("Hello world");

         lines.add("First Line");

         FileUtils.write(fileToWrite1, "Written with FileUtils!");

         FileUtils.writeLines(fileToWrite2, lines);

    }

}