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Articles on Trending Technologies
Technical articles with clear explanations and examples
When can a .class file get created in Java?
A Java class file has a ".class" extension and contains the Java bytecode. This class file can be executed by the Java Virtual Machine (JVM). A ".class" file is created as a result of successful compilation by the Java compiler from the ".java" file. Each class in the .java file is compiled into a separate class file if the ".java " file has more than one class.Exampleclass A { A() { System.out.println("This is class A"); } } class B { B() { ...
Read MoreHow to get website SSL certificate validity dates with PowerShell?
SSL certificates are a very crucial part of the website. They play a key role in securing the exchange of information on both client and server sides by activating an HTTPS secure connection. In the below article with the PowerShell, we will get the certificate validity date (starting and expiry date) for the certificate using PowerShell.To achieve this, we need to make httpwebrequest but before that, we will ignore SSL warning by the below command.[Net.ServicePointManager]::ServerCertificateValidationCallback = { $true }And then we wil make the HTTP web request by calling a .Net class.$url = "https://www.microsoft.com/" $req = [Net.HttpWebRequest]::Create($url)When we check the ...
Read MoreIs there any method to convert a Set to immutable in Java
Whenever you need to create an object which cannot be changed after initialization you can define an immutable object. There are no specific rules to create immutable objects, the idea is to restrict the access of the fields of a class after initialization.A Set is an interface in collection framework, which does not allow duplicate values.Method to convert a set to immutableYes, Java provides a method named unmodifiableSet() in the Collections class. This method accepts a collection object as a parameter and returns an unmodifiable i.ie immutable form of it.ExampleIn the following Java program, we have created a HashSet object ...
Read MoreHow can we check an underflow occurs in Java?
When a value is assigned to a variable that is less than the minimum allowed value for that variable, then an underflow occurs. There is no exception thrown by the JVM if an underflow occurs in Java and it is the responsibility of a programmer to handle the underflow conditions.Examplepublic class UnderlowTest { public static void main(String[] args) { int num1 = -2147483648; int num2 = -1; System.out.println("Number 1: " + num1); System.out.println("Number ...
Read MoreWhy TreeSet Does not allow null values in Java?
TreeSet provides an implementation of the Set interface that uses a tree for storage. Objects are stored in a sorted and ascending order.Access and retrieval times are quite fast, which makes TreeSet an excellent choice when storing large amounts of sorted information that must be found quickly.The reason is, if you look at the internal implementation of the TreeSet, it uses natural ordering, that means TreeSet uses Comparable interface by default to sort its value by comparing other value.Examplepublic class TreeSetDemo { public static void main(String args[]) { TreeSet treeSet = new TreeSet(); ...
Read MoreHow to convert an array to Set and vice versa in Java?
Array is a container which can hold a fix number of entities, which are of the same type. Each entity of an array is known as element and, the position of each element is indicated by an integer (starting from 0) value known as index.Exampleimport java.util.Arrays; public class ArrayExample { public static void main(String args[]) { Number integerArray[] = new Integer[3]; integerArray[0] = 25; integerArray[1] = 32; integerArray[2] = 56; System.out.println(Arrays.toString(integerArray)); } }Output[25, 32, 56]Whereas a Set object is a collection (object) stores ...
Read MoreDifference Between MySql <> NULL and IS NOT NULL?
If you compare the operator with NULL value then you will get NULL value always and no result.Let us see some examples for comparison −mysql> select 10 NULL; +------------+ | 10 NULL | +------------+ | NULL | +------------+ 1 row in set (0.00 sec) mysql> select NULL NULL; +--------------+ | NULL NULL | +--------------+ | NULL | +--------------+ 1 row in set (0.00 sec) mysql> select 'Chris' NULL; +-----------------+ | 'Chris' NULL | +-----------------+ | NULL | +-----------------+ 1 row in ...
Read MoreIs there any way to skip finally block even if some exception occurs in exception block using java?
An exception is an issue (run time error) occurred during the execution of a program. When an exception occurred the program gets terminated abruptly and, the code past the line that generated the exception never gets executed.Try, catch, finally blocksTo handle exceptions Java provides a try-catch block mechanism.A try/catch block is placed around the code that might generate an exception. Code within a try/catch block is referred to as protected code.Syntaxtry { // Protected code } catch (ExceptionName e1) { // Catch block }When an exception raised inside a try block, instead of terminating the program JVM stores ...
Read MoreIs it possible to resume java execution after exception occurs?
An exception is an issue (run time error) occurred during the execution of a program. When an exception occurred the program gets terminated abruptly and, the code past the line that generated the exception never gets executed.There are two types of exceptions in Java.Unchecked Exception − An unchecked exception is the one which occurs at the time of execution. These are also called as Runtime Exceptions. These include programming bugs, such as logic errors or improper use of an API. Runtime exceptions are ignored at the time of compilation.Checked Exception − A checked exception is an exception that occurs at ...
Read MoreHow can we decide that custom exception should be checked or unchecked in java?
An exception is an issue (run time error) occurred during the execution of a program. When an exception occurred the program gets terminated abruptly and, the code past the line that generated the exception never gets executed.User defined exceptionsYou can create your own exceptions in Java and they are known as user defined exceptions or custom exceptions.To create a user defined exception extend one of the above mentioned classes. To display the message override the toString() method or, call the superclass parameterized constructor by passing the message in String format.MyException(String msg){ super(msg); } Or, public String toString(){ return ...
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