Java - Creating Files

Create File in Java

We can create a file in Java using multiple ways. Following are three most popular ways to create a file in Java −

• Using FileOutputStream() constructor

• Using File.createNewFile() method

• Using Files.write() method

Let's take a look at each of the way to create file in Java.

Create File Using FileOutputStream Constructor

FileOutputStream is used to create a file and write data into it. The stream would create a file, if it doesn't already exist, before opening it for output.

Here are two constructors which can be used to create a FileOutputStream object.

Following constructor takes a file name as a string to create an input stream object to write the file −

Syntax

OutputStream f = new FileOutputStream("C:/java/hello.txt") 

Syntax

Following constructor takes a file object to create an output stream object to write the file. First, we create a file object using File() method as follows −

File f = new File("C:/java/hello.txt");
OutputStream f = new FileOutputStream(f);

Example: Create File Using FileOutputStream Constructor

Following is the example to demonstrate FileOutputStream to create a file in current directory−

package com.tutorialspoint;

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

public class FileTest {

   public static void main(String args[]) {
   
      try {
         byte bWrite [] = {65, 66, 67, 68, 69};
         OutputStream os = new FileOutputStream("test.txt");
         for(int x = 0; x < bWrite.length ; x++) {
            os.write( bWrite[x] );   // writes the bytes
         }
         os.close();
     
         InputStream is = new FileInputStream("test.txt");
         int size = is.available();

         for(int i = 0; i < size; i++) {
            System.out.print((char)is.read() + "  ");
         }
         is.close();
      } catch (IOException e) {
         System.out.print("Exception");
      }	
   }
}

The above code would create file test.txt and would write given numbers in binary format. Same would be the output on the stdout screen.

Output

A  B  C  D  E  

Create File Using File.createNewFile() Method

File.createNewFile() method allows to create a file in given location or in current directory as follows −

Syntax

File file = new File("d://test//testFile1.txt");

//Create the file
if (file.createNewFile()) { 
   System.out.println("File is created!");
} else {
   System.out.println("File already exists.");
} 

Example: Create File Using File.createNewFile() Method

Following is the example to demonstrate File to create a file in given directory using createNewFile() method −

package com.tutorialspoint;

import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;

public class FileTest {

   public static void main(String args[]) {
   
      try {
          File file = new File("d://test//testFile1.txt");
          
          //Create the file
          if (file.createNewFile()) { 
             System.out.println("File is created!");
          } else {
             System.out.println("File already exists.");
          } 
          
          // Write Content
          FileWriter writer = new FileWriter(file);
          writer.write("Test data");
          writer.close();
          
          
          // read content
          FileReader reader = new FileReader(file);
          
          int c;
          while ((c = reader.read()) != -1) {
        	  char ch = (char) c;
              System.out.print(ch);
          }
      } catch (IOException e) {
         System.out.print("Exception");
      }	
   }
}

Output

The above code would create file test.txt and would write given string in text format. Same would be the output on the stdout screen.

File is created!
Test data

Create File Using Files.write() Method

Files.write() is a newer and more flexible method create a file and write content to a file in same command as shown below −

Syntax

String data = "Test data";
Files.write(Paths.get("d://test/testFile3.txt"), data.getBytes());

List<String> lines = Arrays.asList("1st line", "2nd line");
Files.write(Paths.get("file6.txt"), lines, StandardCharsets.UTF_8, 
   StandardOpenOption.CREATE, StandardOpenOption.APPEND);

Example: Create File Using Files.write() Method

Following is the example to demonstrate File to create a file in given directory using Files.write() method −

package com.tutorialspoint;

import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.nio.file.StandardOpenOption;
import java.util.Arrays;
import java.util.List;

public class FileTest {

   public static void main(String args[]) {
   
      try {
    	  String data = "Test data";
          Files.write(Paths.get("d://test/testFile3.txt"), data.getBytes());
          List<String> lines = Arrays.asList("1st line", "2nd line");
          Files.write(Paths.get(
             "file6.txt"), lines, StandardCharsets.UTF_8, 
             StandardOpenOption.CREATE, StandardOpenOption.APPEND);
          
          List<String> content = Files.readAllLines(Paths.get("d://test/testFile3.txt"));

          System.out.println(content);
          
          content = Files.readAllLines(Paths.get("file6.txt"));

          System.out.println(content);
      } catch (IOException e) {
         System.out.print("Exception");
      }	
   }
}

Output

The above code would create file test.txt and would write given strings in text format. Same would be the output on the stdout screen.

[Test data]
[1st line, 2nd line]