Creating file in Java

In Java create file tutorial, we show how to create a file in Java. We create files with built-in classes including File, FileOutputStream, and Files. We also use two third-party libraries: Apache Commons IO and Google Guava.

A computer file is a computer resource for recording data discretely in a computer storage device.

The tutorials shows five ways to create a file in Java. The examples create empty files.

Java creating file with File

The File's createNewFile() method creates a new, empty file named by the pathname if a file with this name does not yet exist.

JavaCreateFileEx.java
package com.zetcode;

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

public class JavaCreateFileEx {

    public static void main(String[] args) throws IOException {

        File file = new File("src/main/resources/myfile.txt");

        if (file.createNewFile()) {
            
            System.out.println("File has been created.");
        } else {
        
            System.out.println("File already exists.");
        }
    }
}

The createNewFile() returns true if the named file does not exist and was successfully created; false if the named file already exists.

Java creating file with FileOutputStream

In the second example, we create a new, empty file with FileOutputStream.

JavaCreateFileEx2.java
package com.zetcode;

import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

public class JavaCreateFileEx2 {

    public static void main(String[] args) throws FileNotFoundException, IOException {

        FileOutputStream fout = null;

        try {
            
            fout = new FileOutputStream("src/main/resources/myfile.txt");
        } finally {
            
            if (fout != null) {
                fout.close();
            }
        }
    }
}

The file is created when FileOutputStream object is instantiated. If the file already exists, it is overridden.

FileNotFoundException is thrown if the file exists but is a directory rather than a regular file, does not exist but cannot be created, or cannot be opened for any other reason.

Java creating file with Files

Java 7 introduced Files, which consists exclusively of static methods that operate on files, directories, or other types of files. Its createFile() method creates a new and empty file, failing if the file already exists.

JavaCreateFileEx3.java
package com.zetcode;

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

public class JavaCreateFileEx3 {

    public static void main(String[] args) throws IOException {

        Path path = Paths.get("src/main/resources/myfile.txt");

        try {

            Files.createFile(path);
            
        } catch (FileAlreadyExistsException ex) {
            
            System.err.println("File already exists");
        }
    }
}

The example creates a new, empty file with Files.

Path path = Paths.get("src/main/resources/myfile.txt");

A Path object is created. It is used to locate a file in a file system.

Files.createFile(path);

The new file is created with Files.createFile().

} catch (FileAlreadyExistsException ex) {

FileAlreadyExistsException is thrown if the file already exists.

Java creating file with Apache Commons IO

The next example creates a file with Apache Commons IO library.

<dependency>
    <groupId>commons-io</groupId>
    <artifactId>commons-io</artifactId>
    <version>2.6</version>
</dependency>

For the project we need the commons-io dependency.

JavaCreateFileEx4.java
package com.zetcode;

import java.io.File;
import java.io.IOException;
import org.apache.commons.io.FileUtils;

public class JavaCreateFileEx4 {
    
    public static void main(String[] args) throws IOException {
        
        FileUtils.touch(new File("src/main/resources/myfile.txt"));
    }
}

The new file is created with FileUtils.touch() method.

Java creating file with Google Guava

In the following example, we create a new file with Google Guava library.

<dependency>
    <groupId>com.google.guava</groupId>
    <artifactId>guava</artifactId>
    <version>23.4-jre</version>
</dependency>

For the project we need the guava dependency.

JavaCreateFileEx5.java
package com.zetcode;

import com.google.common.io.Files;
import java.io.File;
import java.io.IOException;

public class JavaCreateFileEx5 {
    
    public static void main(String[] args) throws IOException {
        
        Files.touch(new File("src/main/resources/myfile.txt"));
    }
}

The new file is created with Files.touch(). It accepts a File as a parameter.

In this tutorial, we have shown several ways how to create a file in Java. We have used built-in tools and third-party libraries. You might also be interested in the related tutorials: Copying file in Java, Java file size, Reading text files in Java, Apache FileUtils tutorial, Java Swing tutorial, Java tutorial, Displaying image in Java.