Using Scanner in Java to Create and Read a Text File

This document explains how to use the Scanner class in Java to create a text file, write data into it, and then read that data back.

Objective

This lesson will show you how to:

1. Create a text file in Java.
2. Write data into it (from scanner input).
3. Read that data back from the same file and print it out.

Step 1: Import the Required Classes

This explains the imports.

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Scanner;

• File → represents a file or directory path.
• FileWriter → allows you to write data to a file.
• Scanner → reads input from the keyboard or from a file.
• IOException → handles errors when working with files.

Step 2: Create a Text File and Write Data

Click here and copy my source code into your Eclipse.
The name of the file will be: PX_CreateFileHardCoded_lastname

Files to Submit (Google Classroom)

• PX_CreateFileHardCoded_lastname.png — screenshot inside Eclipse
• PX_CreateFileHardCoded_lastname.java — Java source file
• PX_CreateFileHardCoded_lastname.txt — plain-text copy of your code
• PX_CreateFileHardCoded_lastname.mp4 — short demo video of the program running

This is the location of your file when the execute the program above

Step 3: Read Data Back from the File and Print It

Click here and copy my source code into your Eclipse.
The name of the file will be: PX_ReadOneLine_lastname

Files to Submit (Google Classroom)

• PX_ReadOneLine_lastname.png — screenshot inside Eclipse
• PX_ReadOneLine_lastname.java — Java source file
• PX_ReadOneLine_lastname.txt — plain-text copy of your code
• PX_ReadOneLine_lastname.mp4 — short demo video of the program running

Summary

1. Create the input.dat file with hardcoded data.
2. Read the file input.dat again using Scanner.