Apache Commons IO - FileUtils


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Provides method to manipulates files like moving, opening, checking existence, reading of file etc. These methods use File Object.

Class Declaration

Following is the declaration for org.apache.commons.io.FileUtils Class −

public class FileUtils
   extends Object

Features

  • Methods to write to a file.
  • Methods to read from a file.
  • Methods to make a directory including parent directories.
  • Methods to copy files and directories.
  • Methods to delete files and directories.
  • Methods to convert to and from a URL.
  • Methods to list files and directories by filter and extension.
  • Methods to compare file content.
  • Methods to file last changed date.
  • Methods to calculating a checksum.

Example of FileUtils Class

Here is the input file we need to parse −

Welcome to Howcodex. Simply Easy Learning.

IOTester.java

import java.io.File;
import java.io.IOException;
import java.nio.charset.Charset;

import org.apache.commons.io.FileUtils;

public class IOTester {
   public static void main(String[] args) {
      try {
         //Using FileUtils
         usingFileUtils();
      } catch(IOException e) {
         System.out.println(e.getMessage());
      }
   }

   public static void usingFileUtils() throws IOException {
      //get the file object
      File file = FileUtils.getFile("input.txt");

      //get the temp directory
      File tmpDir = FileUtils.getTempDirectory();

      System.out.println(tmpDir.getName());

      //copy file to temp directory
      FileUtils.copyFileToDirectory(file, tmpDir);

      //create a new file
      File newTempFile = FileUtils.getFile(tmpDir, file.getName());

      //get the content
      String data = FileUtils.readFileToString(newTempFile, Charset.defaultCharset());

      //print the content
      System.out.println(data);
   }
}

Output

It will print the following result.

Temp
Welcome to Howcodex. Simply Easy Learning.
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