Create file in java on linux

4. Using File.createNewFile()

Let's now look at how we can do the same using the java.io.File class:

@Test public void givenUsingFile_whenCreatingFile_thenCorrect() throws IOException

Note that the file must not exist for this operation to succeed. If the file does exist, then the createNewFile() operation will return false.

5. Using FileOutputStream

Another way to create a new file is to use the java.io.FileOutputStream:

@Test public void givenUsingFileOutputStream_whenCreatingFile_thenCorrect() throws IOException < try(FileOutputStream fileOutputStream = new FileOutputStream(FILE_NAME))< >>

In this case, a new file is created when we instantiate the FileOutputStream object. If a file with a given name already exists, it will be overwritten. If, however, the existing file is a directory or a new file cannot be created for any reason, then we'll get a FileNotFoundException.

Additionally, note we used a try-with-resources statement – to be sure that a stream is properly closed.

6. Using Guava

The Guava solution for creating a new file is a quick one-liner as well:

@Test public void givenUsingGuava_whenCreatingFile_thenCorrect() throws IOException

7. Using Apache Commons IO

The Apache Commons library provides the FileUtils.touch() method which implements the same behavior as the “touch” utility in Linux.

Therefore it creates a new empty file or even a file and the full path to it in a file system:

@Test public void givenUsingCommonsIo_whenCreatingFile_thenCorrect() throws IOException

Note that this behaves slightly differently than the previous examples: if the file already exists, the operation doesn't fail, it simply doesn't do anything.

And there we have it – 4 quick ways to create a new file in Java.

8. Conclusion

In this article, we looked at different solutions for creating a file in Java. We used classes that are part of the JDK and external libraries.

The code for the examples is available over on GitHub.

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How to Create/Write a File in Java?

Java provides a predefined class named “File” which can be found in the java.io package. The File class assists us in working with the files as it provides a wide range of methods such as mkdir(), getName(), and many more. If we talk about file creation and writing to the file, the createNewFile(), and write() methods of the File and FileWriter classes can be used respectively.

This write-up provides a profound understanding of the following concepts:

• How to Create a File in Java
• How to Write Data to a File in Java
• Practical Implementation of createNewFile() and write() methods

How to Create a File in Java

The file class provides a createNewFile() method that makes it possible to create an empty file and if a file is created successfully then it returns true, and if the file already exists then we will get a false value.

Example
The below-given code imports two classes: File and IOException of the java.io package:

package filehandlingexample ;
import java.io.File ;
import java.io.IOException ;

public class FileCreationExample {
public static void main ( String [ ] args ) {
try {
File newFile = new File ( "C:JavaFile.txt" ) ;
if ( newFile. createNewFile ( ) ) {
System . out . println ( "File created: " + newFile. getName ( ) ) ;
} else {
System . out . println ( "File Already Exists" ) ;
}
} catch ( IOException excep ) {
System . out . println ( "Error" ) ;
excep. printStackTrace ( ) ;
}
}
}

To create a file, we utilize the object of the File class with the createNewFile() method and the getName() method is used to get the specified name of the File. Moreover, to tackle the exceptions we utilize the try, catch statements, and within the try block, we utilize the if-else statements to handle two possibilities: file created and file already exists. While the catch block will execute to throw an exception:

The above snippet authenticates that the file created successfully.

How to Write Data to a File using write() method in Java

Java provides a built-in class FileWriter that can be used to write data to any file and to do so, the FileWriter() class provides a write() method. While working with the FileWriter class we have to utilize the close() method to close the file.

Example
Let’s consider the below code snippet that writes the data to a file:

public class FileWriteExample {
public static void main ( String [ ] args ) {
try {
FileWriter fileObj = new FileWriter ( "JavaFile.txt" ) ;
fileObj. write ( "Welcome to LinuxHint" ) ;
fileObj. close ( ) ;
System . out . println ( "Data written to the file Successfully" ) ;
} catch ( IOException e ) {
System . out . println ( "Error" ) ;
e. printStackTrace ( ) ;
}
}
}

In the above code snippet, we created an object of the FileWriter class, and within the parenthesis, we specified the file name to whom we want to write the data. Next, we utilize the write() method of the same class to write the data to the file and then close the file using the close() method. Finally, we handled the exceptions in the catch block using the IOException class.

The output validates that the write() method succeeds in writing the data to a file.

Conclusion

In java, the createNewFile(), and write() methods of File and FileWriter classes can be used respectively to create a file and to write data to a specific file. Moreover, we have to utilize the close() method when working with the FileWriter class to close the File. This write-up presents a comprehensive overview of how to create a file and how to write data to a file in java.

About the author

Anees Asghar

I am a self-motivated IT professional having more than one year of industry experience in technical writing. I am passionate about writing on the topics related to web development.

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