Java Articles - Page 192 of 440

In general, arrays are the containers that store multiple variables of the same datatype. These are of fixed size and the size is determined at the time of creation. Each element in an array is positioned by a number starting from 0.You can access the elements of an array using name and position as −System.out.println(myArray[3]); //Which is 1457Creating an array in JavaIn Java, arrays are treated as referenced types you can create an array using the new keyword similar to objects and populate it using the indices as −int myArray[] = new int[7]; myArray[0] = 1254; myArray[1] = 1458; myArray[2] ... Read More

In Java classes and interfaces related to each other are grouped under a package. Package is nothing but a directory storing classes and interfaces of a particular concept. For example, all the classes and interfaces related to input and output operations are stored in java.io package.Creating a packageYou can group required classes and interfaces under one package just by declaring the package at the top of the Class/Interface (file) using the keyword package as −package com.tutorialspoint.mypackage; public class Sample{    public void demo(){       System.out.println("This is a method of the sample class");    }    public static void main(String ... Read More

The java.io package provides various classes to read write data from various sources and destinations.You can read data from user (keyboard) using various classes such as, Scanner, BufferedReader, InputStreamReader, Console etc.Using Scanner classFrom Java 1.5 Scanner class was introduced. This class accepts a File, InputStream, Path and, String objects, reads all the primitive data types and Strings (from the given source) token by token using regular expressions. By default, whitespace is considered as the delimiter (to break the data into tokens).To read data from keyboard you need to use standard input as source (System.in). For each datatype a nextXXX() is ... Read More

In general, whenever you create a file you can restrict/permit certain users from reading/writing/executing a file.In Java files (their abstract paths) are represented by the Files class of the java.io package. This class provides various methods to perform various operations on files such as read, write, delete, rename etc.In addition, this class also provides the following methods −setExecutble() − This method is sued to set the execute permissions to the file represented by the current (File) object.setWritable() − This method is used to set the write permissions to the file represented by the current (File) object.setReadable() − This method is ... Read More

The File classThe class named File of the java.io package represents a file or directory (path names) in the system. This class provides various methods to perform various operations on files/directories.This class provides various methods to manipulate files, The renameTo() method of the File class accepts a String representing a destination file and, renames the abstract file path of the current file to the given one.This method actually moves the file from source path to the destination path.Exampleimport java.io.File; public class MovingFile {    public static void main(String args[]) {       //Creating a source file object       ... Read More

From Java 1.5 Scanner class was introduced. This class accepts a File, InputStream, Path and, String objects, reads all the primitive data types and Strings (from the given source) token by token using regular expressions. By default, whitespace is considered as the delimiter (to break the data into tokens).To read various datatypes from the source using the nextXXX() methods provided by this class.Reading the contents of a file −To read the contents of a file, Scanner class provides various constructors.Sr.NoConstructors and Description1Scanner(File source)Used to read data from the file represented by the given File object.2Scanner(InputStream source)Used to read data from ... Read More

The standard input (stdin) can be represented by System.in in Java. The System.in is an instance of the InputStream class. It means that all its methods work on bytes, not Strings. To read any data from a keyboard, we can use either the Reader class or the Scanner class. Using Reader Class In Java, the Reader class is an abstract class belonging to the java.io package that is used for reading character streams. It is the superclass of all character input streams, such as "BufferedReader", "InputStreamReader", "FileReader", etc. Subclasses of Reader To use the functionality of the Reader class, use its ... Read More

Java provides I/O Streams to read and write data where, a Stream represents an input source or an output destination which could be a file, i/o devise, other program etc.There are two types of streams available −InputStream − This is used to read (sequential) data from a source.OutputStream − This is used to write data to a destination.FileInputStreamThis class reads the data from a specific file (byte by byte). It is usually used to read the contents of a file with raw bytes, such as images.Converting an InputStream object to StringYou can convert an InputStream Object int to a String ... Read More

Java provides I/O Streams to read and write data where, a Stream represents an input source or an output destination which could be a file, i/o devise, other program etc.Based on the data they handle there are two types of streams −Byte Streams − These handle data in bytes (8 bits) i.e., the byte stream classes read/write data of 8 bits. Using these you can store characters, videos, audios, images etc.Character Streams − These handle data in 16 bit Unicode. Using these you can read and write text data only.The Reader and Writer classes (abstract) are the super classes of ... Read More

Java provides I/O Streams to read and write data where, a Stream represents an input source or an output destination which could be a file, i/o devise, other program etc.In general, a Stream will be an input stream or, an output stream.InputStream − This is used to read data from a source.OutputStream − This is used to write data to a destination.Based on the data they handle there are two types of streams −Byte Streams − These handle data in bytes (8 bits) i.e., the byte stream classes read/write data of 8 bits. Using these you can store characters, videos, ... Read More