How to Check if a File Exists Using Java

In this article, we show how to check if a file exists using Java.

This is to see whether a file is physically in a certain directory or not (whether it exists).

Java has a built-in exists() function that we can use to see whether a file exists or not.

The code to check whether a file exists or not is shown below.

import java.io.*; public class Fileexists { public static void main(String[] args) { File f = new File("books.pdf"); if (f.exists()) System.out.println("This file does exist"); else System.out.println("This file does not exist"); } }

So in the file above we create a class called Fileexists.

We then put in our main() method.

In the main method, we create a file object, f, and pass the parameter named "books.pdf" into the this File object.

So at this point in the code, the File object f has the value of books.pdf.

We then call the exists() function through the if statement.

The function is f.exists(). This function returns a boolean value of either true or false. If the file does exist in the directory, it returns true. If the file does not exist in the directory, it returns false. We output the appropriate message based on this boolean value.

Since we didn't specify the path in the parameter passed into the File object, the Java program looks in the current directory, the one storing this Java file, to look for the file name books.pdf.

If you want to specify a directory other than the current directory, then you will have to specify the complete path to the file.

Since this differs according to what operating system you are using, this is the only part of Java that becomes platform dependent.

In a Windows computer, you normally specify the drive you are using with a letter such as the C drive and then specify the path from there to the file that you want to check to see whether or not it exists.

So if you have a file you want to check to see whether it exists in the C:\Users\ directory, then you would write this into the string as "C:\\Users\\"

This is because "\" is an escape character; it's used for escaping strings. To show "\" in a string, you would have to put double forward slashes "\\".

import java.io.*; public class Fileexists { public static void main(String[] args) { File f = new File("C:\\Users\\books.pdf"); if (f.exists()) System.out.println("This file does exist"); else System.out.println("This file does not exist"); } }

And this is all that is required to check to see whether a file exists in a certain directory or not using Java.

Related Resources

How to Check if an Object is a File Using Java

How to Check if a File is a Directory Using Java

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How to Delete a File Using Java

How to Create a New Directory Using Java

How to List All Files in a Directory Using Java

How to Read a File Using Java

How to Write Data to a File Using Java

How to Get the Size of a File Using Java