The method File.createNewFile() is used to create a new file in Java, and it returns a Boolean value: true if the file is created successfully, otherwise false if the file already exists or the operation failed.

import java.io.File; 
import java.io.IOException; 

public class CreateFile
{
 public static void main( String[] args )
 { 
 try {
 
 File file = new File("c:\\nouveau_fichier.txt"); 
 
 if (file.createNewFile()){
 System.out.println("File created!"); 
 }else{
 System.out.println("File already exists."); 
 }
 
 } catch (IOException e) {
 e.printStackTrace(); 
 }
 }
}

Resources:
http://docs.oracle.com/javase/6/docs/api/java/io/File.html#createNewFile()