3.1 Lesson Outcomes

After completing this lesson, learners will be able to:

• Create File objects in Java.
• Access directories and files.
• Use the list() method.
• Display directory contents.
• Perform basic file handling operations.

3.2 Overview

Java provides the File class to manage files and directories in applications. Developers use file handling to:

• access stored data,
• manage directories,
• organize files,
• and process application resources.

The list() method returns the names of files and folders stored inside a directory.

File handling is important in:

• enterprise systems,
• document management,
• data storage,
• and operating system interaction.

Understanding file handling is important because most applications interact with files and directories.

PA2101 — Create File Objects

The File class represents files and directories.

Java Example:

import java.io.File;

File file = new File(“C:/JavaFiles”);

Practical Activity

Learners must:

• import File class,
• create File objects,
• and define file paths.

PA2102 — Check if File or Directory Exists

Java can check whether files or directories exist.

Java Example:

File file = new File(“C:/JavaFiles”);

System.out.println(file.exists());

Practical Activity

Learners must:

• verify files,
• verify directories,
• and display existence results.

PA2103 — Use list() Method

The list() method displays directory contents.

Java Example:

File folder = new File(“C:/JavaFiles”);

String[] files = folder.list();

for (String fileName : files) {

System.out.println(fileName);

}

Practical Activity

Learners must:

• use list() method,
• display file names,
• and navigate directories.

PA2104 — Determine File and Directory Types

Java can determine whether objects are files or directories.

Java Example:

System.out.println(file.isFile());

System.out.println(file.isDirectory());

Practical Activity

Learners must:

• identify file types,
• identify directories,
• and display outputs.

PA2105 — Create Directories

Java supports directory creation.

Java Example:

File folder = new File(“C:/NewFolder”);

folder.mkdir();

Practical Activity

Learners must:

• create directories,
• verify folder creation,
• and display results.

PA2106 — Retrieve File Information

Java provides file information methods.

File Method — Purpose

getName() — Returns file name
getPath() — Returns file path
length() — Returns file size

Java Example:

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

System.out.println(file.getPath());

Practical Activity

Learners must:

• retrieve file information,
• display file details,
• and interpret outputs.

PA2107 — Delete Files and Directories

Java allows deletion of files and directories.

Java Example:

file.delete();

Practical Activity

Learners must:

• delete files,
• remove directories,
• and verify deletion results.

PA2108 — Create Complete File Handling Program

File handling is used in practical Java applications.

Java Example:

import java.io.File;

public class FileExample {

public static void main(String[] args) {

File folder = new File(“C:/JavaFiles”);

String[] files = folder.list();

for (String fileName : files) {

System.out.println(fileName);

}

}

}

Importance of File Handling

File handling supports:

• data storage,
• resource management,
• document processing,
• and enterprise software functionality.

3.5 Key Notes / Summary

• The File class manages files and directories.
• list() displays directory contents.
• Java supports file and directory operations.
• File methods retrieve file information.
• Java can create and delete directories.
• File handling is important in software applications.