Java Articles - Page 243 of 540

What is an OutOfMemoryError and steps to find the root cause of OOM in Java?

raja
Updated on 24-Feb-2020 11:27:10

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The OutOfMemoryError is thrown by JVM, when JVM does not have enough available memory, to allocate. OutOfMemoryError falls into the Error category in Exception class hierarchy.To generate OutOfMemoryErrorWe will allocate a large chunk of memory, which will exhaust heap memory storage.We will keep on allocating the memory and point will reach, when JVM will not have enough memory to allocate, then OutOfMemoryError will be thrown.Once we will catch the OutOfMemory error, we can log the error.ExampleLive Demopublic class OutOfMemoryErrorDemo {    public static void main(String[] args) throws Exception {       int dummyArraySize = 15;       System.out.println("Max JVM memory: " + Runtime.getRuntime().maxMemory()); ... Read More

Can we write any code after throw statement in Java?

Shriansh Kumar
Updated on 16-May-2025 18:29:43

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No, we can not place any code after throw statement, it leads to compile time error. The compiler will show this error as unreachable statement. In Java, the throw statement immediately terminates the current flow of execution, therefore, the code immediate to a throw statement will not be executed. The control is then transferred to the next catch block or the caller method. The throw Keyword in Java The throw keyword is used to throw an exception manually. Whenever it is required to stop the execution of the functionality based on the user-defined logical error condition, we will use this ... Read More

How many types of anonymous inner classes are defined in Java?

raja
Updated on 11-Feb-2020 09:26:32

1K+ Views

An anonymous inner class is an inner class which is declared without any class name at all. In other words, a nameless inner class is called an anonymous inner class. Since it does not have a name, it cannot have a constructor because we know that a constructor name is the same as the class name.We can define an anonymous inner class and create its object using the new operator at the same time in one step.Syntaxnew(argument-list){    // Anonymous class body }Types of Anonymous Inner Class in JavaAnonymous inner class that extends a classAnonymous inner class that implements an interfaceAnonymous inner ... Read More

What are the differences between import and static import statements in Java?

Shriansh Kumar
Updated on 20-May-2025 18:22:18

5K+ Views

The import statement is used to bring certain classes and interfaces from other packages into our Java program, so we can access them without using their fully qualified names. We can use the short name instead. Java also supports static import statements, which were introduced in Java 5. It helps in accessing static members such as methods and constants. In this article, we are going to learn the difference between import and static import statements in Java. The import Statement in Java To access a class or method from another package, we need to either use the fully qualified ... Read More

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Can we write any statements between try, catch and finally blocks in Java?

raja
Updated on 06-Feb-2020 11:53:15

3K+ Views

No, we cannot write any statements in between try, catch and finally blocks and these blocks form one unit.  The functionality of try keyword is to identify an exception object and catch that exception object and transfer the control along with the identified exception object to the catch block by suspending the execution of the try block. The functionality of the catch block is to receive the exception class object that has been sent by the try and catch that exception class object and assigns that exception class object to the reference of the corresponding exception class defined in the catch block. The finally blocks are ... Read More

What are the differences between recursion and iteration in Java?

Shriansh Kumar
Updated on 16-May-2025 19:03:05

3K+ Views

The Recursion and Iteration both repeatedly execute the set of instructions. Recursion is when a function calls itself repeatedly. The iteration is when a loop repeatedly executes until the controlling condition becomes false. The primary difference between recursion and iteration is that recursion repeats the statement in a function, whereas iteration is applied to the set of instructions that we want to execute repeatedly. In this article, we will compare recursion and iteration in Java and discuss the difference between them. Before we proceed, it is important to understand these two concepts with an example. Recursion in Java Recursion is ... Read More

What are unreachable catch blocks in Java?

Shriansh Kumar
Updated on 20-May-2025 19:24:08

6K+ Views

A block of statements that the program control can never reach under any circumstances can be called an unreachable block. Java does not support unreachable blocks, such code will cause a compile-time error. Any code that is written but never executed is considered unnecessary by the Java compiler. In this article, we will discuss unreachable catch blocks in Java. But, before that, let's understand what is a catch-block in Java. The catch Block in Java The catch block is written just after the try block and cannot have any code between them. It is an exception handler and contains code ... Read More

Why Char[] array is more secure (store sensitive data) than String in Java?

Shriansh Kumar
Updated on 20-May-2025 19:16:27

5K+ Views

Both String class and Char[] array in Java are used to store textual data. However, Strings are immutable, which means you can't make changes to a String once defined, and the char[] array is not immutable. In the official documentation of Java Cryptography Architecture, it is clearly written that String objects are not suitable for storing sensitive data, such as passwords, SSN, etc. Use a char array instead, as it is more secure than String. This article will help you understand why char[] array is used to store sensitive data. Char Array is more secure than String Let's discuss why ... Read More

What is the contract between equals() and hashCode() methods in Java?

Shriansh Kumar
Updated on 21-May-2025 15:49:06

16K+ Views

Every Java object has two very important methods,  equals() and hashCode(), and these methods are designed to be overridden according to their specific general contract. Since the Object class is the parent class of every class, the default implementation of the equals() and hashCode() methods is already present in each class. However, we need to override these methods based on the requirement. Let's discuss the contract between equals() and hashCode() methods in Java. But before that, we need to understand these methods. The hashCode() Method The hashCode() method returns an integer value, which is referred to as the hash code value ... Read More

What are the differences between tight coupling and loose coupling in Java?

Shriansh Kumar
Updated on 20-May-2025 18:33:46

17K+ Views

In object-oriented programming, coupling is a term used to describe the level of dependency each class or component of an application has on another. Tight coupling in Java means features of different classes and objects have high dependence on one another, whereas Loose coupling means components have very low or no dependency on one another. This article explains how tight coupling is different from loose coupling in Java. Tight Coupling in Java In tight coupling, if the implementation of one class changes, the dependent class might also need to be changed. It makes Java code less flexible and more difficult ... Read More

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