How to Create File In Java

Create File with java.io.File class

We can use java.io.File class for create file in java . We will use createNewFile() method of File class to create new file. First we create object of File Class and pass path with name of file inside constructor of object . After that we will call cretaeNewFile() method and it creates a new, empty file named by given pathname if and only if a file with this name does not yet exist.

Syntax :

public boolean createNewFile(){
}

Return Value : It is return true if the named file does not exist and was successfully created otherwise  false if the named file already exists .

Exception : It throws following exceptions                                                                    IOException – If an I/O error occurred during creation of file .
SecurityException – This exception occur If a security manager exists and its java.lang.SecurityManager.checkWrite(java.lang.String) method denies write access to the file

Now we will see how to create new file in java using java.io.File.createNewFile() method .

package com.demo.file;
import java.io.File;
import java.io.IOException;

public class CreateFileJavaExamples {
	public static void main(String[] args) {
                //create file object with  file path
		File file = new File("C://java_examples//newFile.txt");
		try {
			if (file.createNewFile()) { //return true if file created 
                               //otherwise return flase
				System.out.println("File create");
			} else { 
				System.out.println("File already exists!");
			}
		} catch (IOException e) {
			e.printStackTrace();
		}

	}
}

If we use invalid path then it will throw java.io.IOException . In below example we use invalid path which does not exits .

package com.demo.file;
import java.io.File;.
import java.io.IOException;

public class CreateFileJavaExamples {
	public static void main(String[] args) {
		File file = new File("C://java_//newFile.txt");
		try {
			if (file.createNewFile()) {
				System.out.println("File create");
			} else {
				System.out.println("File already exists!");
			}
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
}

Output :

java.io.IOException: The system cannot find the path specified
	at java.io.WinNTFileSystem.createFileExclusively(Native Method)
	at java.io.File.createNewFile(Unknown Source)
	at com.demo.file.CreateFileJavaExamples.main(CreateFileJavaExamples.java:11)

So be careful when creating file you must have to use valid path .

Create File Using java.io.FileOutputStream

In this example we use Fileoutputstream class to create file in java . Fileoutputstream class have multiple constructors , we use FileOutputStream(String name, boolean append) constructors to create file .

Syntax :

public FileOutputStream(String name, boolean append) throws FileNotFoundException

Parameter :

Name : name of the file                                                                                                        append : if true, then bytes will be written to the end of the file not in the beginning

Exceptions :

FileNotFoundException – If the file exists but directory not , cannot be created, or cannot be opened for any other reason
SecurityException – If a security manager exists and its checkWrite method denies write access to the file.

Let’s see example for Fileoutputstream class

package com.demo.file;

import java.io.FileOutputStream;

public class CreateFileJavaExamples2 {
	
	public static void main(String[] args) {
		 try {
	            new FileOutputStream("C://java_examples//newFile1.txt", true);
	            System.out.println("file created successfully");
	        } catch (Exception e) {
	        	e.printStackTrace();
	        }
	}
}

Create File with java.nio Package

We can create file using createFile() metho of java.nio.file.Files class . In this example first we will set path of file with the help of java.nio.file.Path object after that we will create file using createFile() method of Files class .

Syntax :

public static Path createFile(Path path, FileAttribute<?>... attrs)
        throws IOException

Parameter :

path :  The path of the file
attrs : An optional list of file attributes .

Return value :  This method return file .

Exception : It is throws following exceptions                                                UnsupportedOperationException – It thows if the attr array contains an attribute that cannot be set atomically when creating the file .
FileAlreadyExistsException – if a file name already exists .
IOException – if an I/O error occurs or the parent directory does not exist
SecurityException – In the case of the default provider, and a security manager is installed, the checkWrite method is invoked to check write access to the new file.

package com.demo.file;

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;

public class CreateFileJavaExamples3 {
	public static void main(String[] args) {
		
		 try {
	            Path newFilePath = Paths.get("C://java_examples//newFile3.txt");
	            Files.createFile(newFilePath);
	            System.out.println("File Created Successfully");
	        }catch (IOException e) {
	        	e.printStackTrace();
	        }
	}

}

We have learned different method for creating files in java . You can see more java file handling examples .

Javadoc: createNewFile()