You can get the size of a directory with the help of FileUtils.sizeofDirectory(File Name) method of FileUtils class.Exampleimport java.io.File; import org.apache.commons.io.FileUtils; public class Main {    public static void main(String[] args) {       long size = FileUtils.sizeOfDirectory(new File("C:/Windows"));       System.out.println("Size: " + size + " bytes");    } }OutputSize: 2048 bytes

Following example shows the way to look for a particular file in a directory by creating a File filter. Following example displays all the files having file names beginning with 'b'.ExampleLive Demoimport java.io.*; public class Main {    public static void main(String[] args) {       File dir = new File("C:");             FilenameFilter filter = new FilenameFilter() {          public boolean accept (File dir, String name) {             return name.startsWith("b");          }       };       String[] children = ... Read More

The java.io.File.mkdirs() creates the directory named by this abstract pathname, together with necessary and non-existent parent directories.ExampleLive Demoimport java.io.File; public class Main {    public static void main(String[] args) {       String directories = "D:\a\b\c\d ";       File file = new File(directories);       boolean result = file.mkdirs();       System.out.println("Status = " + result);    } }OutputStatus = true

The file class provides a method named exists() which returns true if the file specified in the current file object exists.ExampleLive Demoimport java.io.File; public class FileHandling {    public static void main(String args[]) {       File file = new File("samplefile");       if(file.exists()) {          System.out.println("Given file existed");       } else {          System.out.println("Given file does not existed");      }    } }OutputGiven file does not existed

You can get the list of files in a directory −Create a directory object using the File class.Get the list of directories in it using the getName() method.Exampleimport java.io.File; public class FindingDirectories {    public static void main(String args[]) {       String dir ="C:/Users/Tutorialspoint/Desktop/movies";       File directory = new File(dir);       File[] fileList = directory.listFiles();       for(File file: fileList) {          System.out.println(file.getName());       }    } }OutputArundhati HD.mp4 Okka Ammai Tappa.mkv Padamati Sandhya Ragam.mp4

The println() terminates the current line by writing the line separator string. The print() method just prints the given content.ExampleLive Demopublic class Sample {    public static void main(String args[]) {       System.out.println("Hello");       System.out.println("how are you");       System.out.print("Hello");       System.out.print("how are you");    } }OutputHello how are you Hellohow are you

All the programming languages provide support for standard I/O where the user's program can take input from a keyboard and then produce an output on the computer screen. Similarly, Java provides the following three standard streams:Standard Input: This is used to feed the data to user's program and usually a keyboard is used as a standard input stream and represented as System.in.Standard Output: This is used to output the data produced by the user's program and usually a computer screen is used for standard output stream and represented as System.out.Standard Error: This is used to output the error data produced ... Read More

Serialization Java provides a mechanism, called object serialization where an object can be represented as a sequence of bytes that includes the object's data as well as information about the object's type and the types of data stored in the object.Exampleimport java.io.*; public class SerializeDemo {    public static void main(String [] args) {       Employee e = new Employee();       e.name = "Reyan Ali";       e.address = "Phokka Kuan, Ambehta Peer";       e.SSN = 11122333;       e.number = 101;       try {         ... Read More

Externalization is used whenever we need to customize serialization mechanism. If a class implements an Externalizable interface then, object serialization will be done using writeExternal() method.Whereas at receiver’s end when an Externalizable object is a reconstructed instance will be created using no argument constructor and then the readExternal() method is called.If a class implements only Serializable interface object serialization will be done using ObjectoutputStream.At the receiver’s end, the serializable object is reconstructed using ObjectInputStream.

After a serialized object has been written into a file, it can be read from the file and Deserialized that is, the type information and bytes that represent the object and its data can be used to recreate the object in memory.Exampleimport java.io.*; public class DeserializeDemo {    public static void main(String [] args) {       Employee e = null;       try {          FileInputStream fileIn = new FileInputStream("/tmp/employee.ser");          ObjectInputStream in = new ObjectInputStream(fileIn);          e = (Employee) in.readObject();          in.close(); ... Read More