Creating & Writing Text Files in Java (Part 6)

 Pre-requisites:- Exception Handling , Reading Files 

Creating a Text File

A text file can be created by many ways , here I will try to show the most used ways to create a text file. Firstly , we will learn to create a text file by using File class which is by far the most popular way to create a text file. 

• First we have to create an instance of File class , then we have to call a method .createNewFile( ) which is a boolean i.e will return true or false.

• Also this method is suspicious of throwing an IOException so we have to catch it using a try-catch block.

• If file is created the .createNewFile( ) returns true if file is created or if file name mentioned exists previously in any form returns a false value.

 import java.io.File;  
 import java.io.IOException;  
   
 public class MyClass {  
   public static void main(String[] args) {  
     File file = new File("example.txt");   //this will create a text file named example
     try {  
       if(file.createNewFile()==true) {  
         System.out.println("New File created: "+file.toString());  
       }  
       else {  
         System.out.println("The file already exists: "+file.toString());  
       }  
     } catch (IOException e) {  
       System.out.println("Unable to perform I/O operations on file: "+file.toString());  
     } finally {  
       System.out.println("File is located at: "+file.getAbsolutePath());  
     }  
   }  
 }  

Output:-

 New File created: example.txt  
 File is located at: C:\Users\workspace\JavaProgram1\example.txt  

Here the method .getAbsolutePath( ) returns the path of the file where it is saved in the system.

Writing a Text File

There are two ways to write a text file in Java :

1. Without specifying location of the file

• For this , we must create a text file in our own folder where our code is written.

• First In the Left-side section i.e where your projects are displayed , right-click on your project then a pop-up menu will open select New and then File.

• Give your file a name with extension .txt mentioning it is text file and that name would be used in the code.

Now when you have declared a file , its time to apply your logic into the java code. Here we are using the FileWriter class to write data into files.

 import java.io.File;  
 import java.io.FileWriter;  
 import java.io.IOException;  
   
 public class MyClass {  
   public static void main(String[] args) {  
     File file = new File("example.txt");  
     try {  
       FileWriter fw = new FileWriter(file);  
       fw.write("Hello");  
       fw.write("\n");  
       fw.write("Welcome");  
       fw.write("\n");  
       fw.write("To Java Monk");  
       fw.close();  
     } catch (IOException e) {  
       System.out.println("Unable to read/write file");  
     }  
   }  
 }  

Output:- ( In File )

 Hello  
 Welcome  
 To Java Monk  

2. By specifying location of the file

We also can create a text file where we have to give an instance path to the file we have created. The file  will be stored at that location in our system.

 import java.io.File;  
 import java.io.FileWriter;  
 import java.io.IOException;  
   
 public class MyClass {  
   public static void main(String[] args) {  
     File file = new File("C:\\Users\\bharg\\Desktop\\example.txt");  
     try {  
       FileWriter fw = new FileWriter(file);  
       fw.write("Hello");  
       fw.write("\n");  
       fw.write("Welcome");  
       fw.write("\n");  
       fw.write("To Java Monk");  
       fw.close();  
     } catch (IOException e) {  
       System.out.println("Unable to read/write file");  
     }  
   }  
 }  

Output:-

We also can use many other ways to write a file:

1. Using BufferedWriter

BufferedWriter is used when number of file operations are more because it performs better than the FileWriter.

 import java.io.BufferedWriter;  
 import java.io.File;  
 import java.io.FileWriter;  
 import java.io.IOException;  
   
 public class MyClass {  
   public static void main(String[] args) {  
     File file = new File("example.txt");  
     try {  
       FileWriter fw = new FileWriter(file);  
   
     //Used to wrap FileWriter  
       BufferedWriter bw = new BufferedWriter(fw);  
       bw.write("Hello");  
       bw.write("\n");  
       bw.write("Welcome");  
       bw.write("\n");  
       bw.write("To Java Monk ! ");  
       bw.write("\n");  
       bw.write("------Written by BufferedWriter");  
       bw.close();  
     } catch (IOException e) {  
       System.out.println("Unable to read/write file");  
     }  
   }  
 }  

Output:- ( In File )

 Hello  
 Welcome  
 To Java Monk !   
 ------Written by BufferedWriter  

2. Using FileOutputStream

When any raw stream data is to be written , FileOutputStream is used.

 import java.io.File;  
 import java.io.FileOutputStream;  
 import java.io.IOException;  
   
 public class MyClass {  
   public static void main(String[] args) {  
     File file = new File("example.txt");  
     try {  
       FileOutputStream fos = new FileOutputStream(file);  
   
       // First take input as a string  
       String line1 = "Hello";  
   
       // convert it into array of bytes  
       byte[] arr1 = line1.getBytes();  
   
       // write to file  
       fos.write(arr1);  
   
       String line2 = "\n";  
       byte[] arr2 = line2.getBytes();  
       fos.write(arr2);  
   
       String line3 = "----Written by FileOutputStream";  
       byte[] arr3 = line3.getBytes();  
       fos.write(arr3);  
       fos.close();  
     } catch (IOException e) {  
       System.out.println("Unable to read/write file");  
     }  
   }  
 }  

Output:- ( In File )

 Hello  
 ----Written by FileOutputStream  

Also there are more functionalities through which we can read files , but for now you must know the above functionalities used to write files.

Let's see a program where user can input the contents of file in it . Here I have used FileWriter to write contents to file.

 import java.io.File;  
 import java.io.FileWriter;  
 import java.io.IOException;  
 import java.util.Scanner;  
   
 public class MyClass {  
   public static void main(String[] args) {  
     System.out.println("Welcome to FileWriter !");  
     System.out.println("--------------------------");  
     System.out.println("Enter a file name:");  
       
     Scanner scan = new Scanner(System.in);  
     String fileName = scan.nextLine();  
     File file = new File(fileName);  
     FileWriter fw = null;  
       
     try {  
       fw = new FileWriter(file);  
       System.out.println("--------------------------");  
       System.out.println("File created: " + file.toString());  
       System.out.println("File Location: " + file.getAbsolutePath());  
       System.out.println("--------------------------");  
         
       System.out.println("Enter number of lines you wish to write on file:");  
       int entry = scan.nextInt();  
       int i = 0;  
       System.out.println("--------------------------");  
       System.out.println("Enter contents in file:");  
         
       while (i <= entry) {  
         String line = scan.nextLine();  
         fw.write(line+"\n");  
         i++;  
       }  
         
       System.out.println("--------------------------");  
       System.out.println("File Saved: " + file.toString());  
       System.out.println("--------------------------");  
       System.out.println("You can check out your file at location: "+file.getAbsolutePath());  
   
     } catch (IOException e) {  
       System.out.println("Unable to read/write on file: "  
           + file.toString());  
     } finally {  
       try {  
         fw.close();  
       } catch (IOException e) {  
         System.out.println("Unable to close file: " + file.toString());  
       }  
     }  
   }  
 }  

Output:-

 Welcome to FileWriter !  
 --------------------------  
 Enter a file name:  
 example.txt  
 --------------------------  
 File created: example.txt  
 File Location: C:\Users\bharg\workspace\Example\example.txt  
 --------------------------  
 Enter number of lines you wish to write on file:  
 5  
 --------------------------  
 Enter contents in file:  
 Hello   
 I am Java Monk   
 Trying to make world a better place by teaching Java to all the beginners  
 Wrote that because I was not able to think of something else  
 Thank You  
 --------------------------  
 File Saved: example.txt  
 --------------------------  
 You can check out your file at location: C:\Users\bharg\workspace\Example\example.txt  

In File: 

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