Enumerations in Java represents a group of named constants, you can create an enumeration using the following syntaxenum Days {    SUNDAY, MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY }Yes, we can define an enumeration inside a class. You can retrieve the values in an enumeration using the values() method.ExampleLive Demopublic class EnumerationExample {    enum Enum {       Mango, Banana, Orange, Grapes, Thursday, Apple    }    public static void main(String args[]) {       Enum constants[] = Enum.values();       System.out.println("Value of constants: ");         for(Enum d: constants) {         ... Read More

Following example prints the files in a directory based on the extensions −Exampleimport java.io.IOException; import java.nio.file.Files; import java.nio.file.Path; import java.nio.file.Paths; import java.util.stream.Stream; public class Demo {    public static void main(String[] args) throws IOException {       Stream path = Files.walk(Paths.get("D:\ExampleDirectory"));       System.out.println("List of PDF files:");       path = path.filter(var -> var.toString().endsWith(".pdf"));       path.forEach(System.out::println);             path = Files.walk(Paths.get("D:\ExampleDirectory"));       System.out.println("List of JPG files:");       path = path.filter(var -> var.toString().endsWith(".jpg"));       path.forEach(System.out::println);           path = Files.walk(Paths.get("D:\ExampleDirectory"));       ... Read More

The ListFiles() method returns an array holding the objects (abstract paths) of all the files (and directories) in the path represented by the current (File) object.The File Filter interface is filter for the path names you can pass this as a parameter to the listFiles() method. This method filters the file names passed on the passed filter.To get the hidden directories in a folder, implement a FileFilter which accepts only hidden directories, and pass it as a parameter to the listFiles() method.Exampleimport java.io.File; import java.io.FileFilter; import java.io.IOException; public class Test{    public static void main(String args[]) throws IOException {   ... Read More

While you use the methods that causes IllegalArgumentException, since you know the legal arguments of them, you can restrict/validate the arguments using if-condition before-hand and avoid the exception.We can restrict the argument value of a method using the if statement. For example, if a method accepts values of certain range, you can verify the range of the argument using the if statement before executing the method.ExampleFollowing example handles the IllegalArgumentException caused by the setPriority() method using the if statement.Live Demoimport java.util.Scanner; public class IllegalArgumentExample {    public static void main(String args[]) {       Thread thread = new Thread(); ... Read More

The ListFiles() method returns an array holding the objects (abstract paths) of all the files (and directories) in the path represented by the current (File) object.The File Filter interface is filter for the path names you can pass this as a parameter to the listFiles() method. This method filters the file names passed on the passed filter.To get the directories in a folder implement a FileFilter which accepts only empty directories, and pass it as a parameter to the listFiles() method.Exampleimport java.io.File; import java.io.FileFilter; import java.io.IOException; public class MyExample{    public static void main(String args[]) throws IOException {     ... Read More

Array is a container which can hold a fix number of items and these items should be of the same type. Most of the data structures make use of arrays to implement their algorithms. Following are the important terms to understand the concept of Array.Element: Each item stored in an array is called an element.Index: Each location of an element in an array has a numerical index, which is used to identify the element.Creating object arraysYes, since objects are also considered as datatypes (reference) in Java, you can create an array of the type of a particular class and, populate ... Read More

The ListFiles() method returns an array holding the objects (abstract paths) of all the files (and directories) in the path represented by the current (File) object.The File Filter interface is filter for the path names you can pass this as a parameter to the listFiles() method. This method filters the file names passed on the passed filter.To get the directories in a folder implement a FileFilter which accepts only directories and pass it as a parameter to the listFiles() method.Following is a screen shot of the contents of the ExampleDirectoryExampleimport java.io.File; import java.io.FileFilter; import java.io.IOException; public class MyExample{    public ... Read More

The ListFiles() method returns an array holding the objects (abstract paths) of all the files (and directories) in the path represented by the current (File) object.The File Filter interface is filter for the path names you can pass this as a parameter to the listFiles() method. This method filters the file names passed on the passed filter.To get the files in a folder implement a FileFilter which accepts only files and pass it as a parameter to the listFiles() method.Following is a screen shot of the contents of the ExampleDirectoryExampleimport java.io.File; import java.io.FileFilter; import java.io.IOException; public class Demo{    public ... Read More

The listFiles() method of the File class returns an array holding the objects (abstract paths) of all the files (and directories) in the path represented by the current (File) object.To read the contents of all the files in a folder into a single file −Create a file object by passing the required file path as a parameter.Read the contents of each file using Scanner or any other reader.Append the read contents into a StringBuffer.Write the StringBuffer contents into the required output file.Exampleimport java.io.DataOutputStream; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.util.Scanner; public class Test {    public static void main(String ... Read More

The List() method of the File class returns a String array containing the names of all the files and directories in the path represented by the current (File) object.In order to search for a file you need to compare the name of each file in the directory to the name of the required file using the equals() method.ExampleLive Demoimport java.io.File; import java.util.Arrays; import java.util.Scanner; public class Example {    public static void main(String[] argv) throws Exception {       System.out.println("Enter the directory path: ");       Scanner sc = new Scanner(System.in);       String pathStr = sc.next(); ... Read More