Java File Operations

File operations in Java.

A File is an abstract data type in Java. Creating, writing, reading, deleting, and retrieving information are all File Operations. [1]

Hierarchy of I/O Classes in Java[2]

For Access: https://cbarkinozer.medium.com/java-file-operations-df292593a756?source=friends_link&sk=8a9fd25e81b083df5ad84a115b6ec029

To understand file operations we need to understand streams. [1]

Stream

A stream refers to a series of data. In Java, Streams in Java are divided into two types: Byte Stream and Character Stream.[1]

Byte Stream deals mostly with byte data. A file handling process with a byte stream is one in which the byte data is used to execute an input. Java byte streams are utilized to perform 8-bit byte input and output. For secure processes, this is the best option.[1][2]

Character Stream’s major focus is character data. A file handling procedure with a character stream is one in which an input is given and the character data is executed. Java Character streams are used to perform input and output for 16-bit Unicode [1][2]

Java File Class Methods: [1]

Boolean canRead(): Can we read the file’s data?

Boolean createNewFile(): Creates a new empty file.
Boolean canWrite(): Can we write the data into the file?

Boolean exists(): Is the specified file present?

Boolean delete(): Deletes a file.

String getName(): Finds the file name.

Boolean getAbsolutePath() : Gets the absolute pathname of the file.

Long length(): Gets the size of the file in bytes.

String[] list(): Array of the files available in the directory.

Get Cahit Barkin Ozer’s stories in your inbox

Join Medium for free to get updates from this writer.

Remember me for faster sign in

Boolean mkdir() : Creats a new directory.

Example to file operations[1]

Note: This code shows overall how and where to use file methods. Please do not use this much code in a single Try block.

import java.io.File;// File class
import java.io.IOException; // IOException for errors
class CreateFile {
public static void main(String args[]) {
try {
// Creating an object of a file
File f0 = new File(“D:FileOperationExample.txt”);
if (f0.createNewFile()) {
  System.out.println(f0.getName());
  // Getting path of the file
  System.out.println(f0.getAbsolutePath());
  // Checking whether the file is writable or not
  System.out.println(f0.canWrite());
  // Checking whether the file is readable or not
  System.out.println(f0.canRead());
  // Getting the length of the file in bytes
  System.out.println(f0.length());
  }
 // Writing the content into the FileOperationExample.txt file
fwrite.write("A named location used to store related information is referred to as a File.");
Scanner dataReader = new Scanner(f1);
while (dataReader.hasNextLine()) {
String fileData = dataReader.nextLine();
System.out.println(fileData);
}
fwrite.close(); // Closing the stream
//Using delete() in if() as depicted, shows the deleted file's name
if (f0.delete()) {
  System.out.println(f0.getName());
  }
String dirname = "/tmp/user/java/bin";
File d = new File(dirname);
d.mkdirs();// Create directory now.
file = new File("/tmp");
// List downs all the files and directories available in a directory as array of files
paths = file.list(); 

} else {
System.out.println(“File is already exist in the directory.”);
}
} catch (IOException exception) {
System.out.println(“An error is occurred.”,exception);
exception.printStackTrace();
}}}

Please do not forget to clap if you enjoyed my article. Thank you.

Source:

[1]javatpoint,(2021), File Operaitons in Java:

[https://www.javatpoint.com/file-operations-in-java]

[2]tutorialspoint,(2021), Java Files IO:

[https://www.tutorialspoint.com/java/java_files_io.htm]