Java Create and Write To Files
Create a File
To create a file in Java, you can use the createNewFile()
method. This method returns a
boolean value: true
if the file was successfully created, and false
if the file
already exists. Note that the method is enclosed in a try...catch
block. This is necessary because it throws an IOException
if an error occurs (if the
file cannot be created for some reason):
Example
import java.io.File; // Import the File class
import java.io.IOException; // Import the IOException class to handle errors
public class CreateFile {
public static void main(String[] args) {
try {
File myObj = new File("filename.txt");
if (myObj.createNewFile()) {
System.out.println("File created: " + myObj.getName());
} else {
System.out.println("File already exists.");
}
} catch (IOException e) {
System.out.println("An error occurred.");
e.printStackTrace();
}
}
}
The output will be:
File created: filename.txt
To create a file in a specific directory (requires permission), specify the path of the file and use double backslashes to escape the "\
" character (for Windows). On Mac and Linux you can just write the path, like: /Users/name/filename.txt
Write To a File
In the
following example, we use the FileWriter
class together with its write()
method
to write some text to the file we created in the example above. Note that when you are done writing to the file,
you should close it
with the close()
method:
Example
import java.io.FileWriter; // Import the FileWriter class
import java.io.IOException; // Import the IOException class to handle errors
public class WriteToFile {
public static void main(String[] args) {
try {
FileWriter myWriter = new FileWriter("filename.txt");
myWriter.write("Files in Java might be tricky, but it is fun enough!");
myWriter.close();
System.out.println("Successfully wrote to the file.");
} catch (IOException e) {
System.out.println("An error occurred.");
e.printStackTrace();
}
}
}
The output will be:
Successfully wrote to the file.
To read the file above, go to the Java Read Files chapter.