Java Articles - Page 182 of 440

A JSlider is a subclass of JComponent class and it is similar to scroll bar which allows the user to select a numeric value from a specified range of integer values. A JSlider has a knob which can slide on a range of values and can be used to select a particular value. and it can generate a ChangeListener interface.We can detect the value changed when the slider is moved horizontally using the Graphics2D class and override paint() method.Exampleimport java.awt.*; import java.awt.event.*; import javax.swing.*; import javax.swing.event.*; public class ValueChangeJSliderTest extends JFrame {    private JSlider slider;    public ValueChangeJSliderTest() { ... Read More

The Character class is a subclass of the Object class, and it wraps a value of the primitive type char in an object. An object of type Character class contains a single field whose type is char. We can print all the capital letters of a given string using the following approaches - Using isUpperCase() Method Using ASCII Comparison Using isUpperCase() Method The isUpperCase() is the method of the Character class. It accepts a character as a parameter and returns true if it is an uppercase letter and false if not.To ... Read More

An Iterable interface is defined in java.lang package and introduced with Java 5 version. An object that implements this interface allows it to be the target of the "for-each" statement. This for-each loop is used for iterating over arrays and collections. An Iterable interface can also be implemented to create custom behavior. Syntax public interface Iterable Example import static java.lang.String.format; import java.util.*; // Person class class Person { private String firstName, lastName; private int age; public Person(){ } public Person(String firstName, String lastName, int age) { this.firstName = firstName; ... Read More

A method in Java is a set of statements that can be reused in the program whenever we want. We can write a method once and call it multiple times. We can return values from a method; the datatype of the value we return is known as the return type.  We return values from a Java method using a return statement. A return statement causes the program control to transfer back to the caller of a method. Every method in Java is declared with a return type, ... Read More

Java supports file-handling; it provides various classes that provide various methods to read, write, update, and delete data from files in our local system. A properties file is a simple text file with a ".properties" extension that contains configuration data in the form of key-value pairs. It is mostly used in Java applications to manage settings such as database configuration, application messages, or environment variables. How to read Data from a Properties File in Java? To read data from the properties file, you can use the Properties class in Java. This is a subclass of the Hashtable class and it represents a persistent ... Read More

A static inner class can be instantiated without the need for an instance of the outer class. In general, an Inner class is a part of nested class, called Non-static nested classes in Java. The types of inner classes are member inner class, anonymous inner class, and local inner class. We can instantiate a static inner class with reflection using InnerClass.class.newInstance(). If we need an instance of the outer class to instantiate a non-static inner class, we can specify it before a new operator. Example import java.lang.reflect.*; public class InnerclassWithReflectionTest { public static void main(String args[]) { ... Read More

Bitwise XOR (exclusive or) "^" is an operator in Java that provides the answer '1' if both of the bits in its operands are different; if both of the bits are the same, then the XOR operator gives the result '0'. XOR is a binary operator that is evaluated from left to right. The operator "^" is undefined for the argument of type String. Importance of the XOR (^) Operator in Java In Java, the XOR (^) operator is important for both bitwise and boolean operations. It returns true or 1 only when the two operands "differ". XOR is commonly ... Read More

Input and output Streams in Java are objects that accepts sequence of information and sends them further. These are used to read and write data from/to various sources.What are Output Streams & WritersA Java output streams accept output data (bytes) from a source and sends it to the destination. An output stream is represented by an abstract class known as OutputStream. This is the super class of all the OutputStream classes. There are various output streams in Java namely, ByteArrayOutputStream, FileOutputStream, FilterOutputStream, ObjectOutputStream, PipedOutputStream.Writers are objects that are used to write data to character streams. These are represented by the abstract ... Read More

In Java, formatted text refers to those text that has been processed and arranged according to a specific format. According to the article, we will use the printf() method to learn how to print the formatted text. Formatted Text using printf() Method In Java, to print the formatted output or text we have a printf() method. The printf() method allows us to format output to a java.io.PrintStream or java.io.PrintWriter. These classes also contain a method called format() which can produce the same results, so whatever we read here for the printf() method can also be applied to the format() method. ... Read More

In Java, both deepToString() and asList() methods are static methods of the Arrays class. An array is an object that holds a fixed number of values of a similar type in a contiguous memory location. The deepToString() Method In Java, the deepToString() method is used to convert a multi-dimensional array into a string. It checks if any element in the array is also an array; it will convert that inner array to a string as well. Syntax Following is the syntax of the Arrays.deepToString() method: public static String deepToString(Object[] a) Here, a: An array ... Read More