Creating file in Java

last modified January 27, 2024

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.

Source

Java Reading, Writing, and Creating Files - tutorial

In this article we have shown several ways how to create a file in Java. We have used built-in tools and third-party libraries.

Author

My name is Jan Bodnar, and I am a passionate programmer with extensive programming experience. I have been writing programming articles since 2007. To date, I have authored over 1,400 articles and 8 e-books. I possess more than ten years of experience in teaching programming.

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