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Since its inception, Java has been incredibly popular among all other programming languages. And the capacity to provide distinctive features is what accounts for the enormous response. Although Java’s syntax is virtually identical to C++’s, it offers many more functionalities. Visit our free technology classes to gain a competitive advantage. Java stood apart from all other languages at the time because to the availability of object-oriented programming (OOP). Java was created with OOP at its heart, which is one of the reasons it is one of the most popular languages. This idea facilitates smooth execution and increased reusability. We may be asking ourselves, “Why should we utilize an object at this time?”. In this article, you will get a clear idea of what is platform independent.
The way that related methods and variables are bound together in Java objects is similar to how they are in C structures. Additionally, Java offers abstraction, encapsulation, inheritance, and polymorphism, all of which encourage the implementation of objects by the user. Java is widely used in numerous fields, including the creation of software tools, websites, and mobile applications. Additionally, it features a large number of libraries, which facilitates operations. Additionally, the availability of IDE is quite important in attracting developers’ attention. Developers typically utilize IDEs like Eclipse, IntelliJ, and NetBeans. Java is essentially Write Once Run Anywhere since it can run on a variety of computing platforms. The fact that Java is portable is a key factor in why it is superior to the C language.
Compiling a Code
Every time we create code, we adhere to a programming language’s grammar, which is generally readable. A few terms, phrases, variable names, method names, etc. are also included. All of them are regarded as literature that can be read and understood by humans. If full-stack development is of interest to you, enroll in our full-stack development Bootcamp course.
As a result, a computer utilizes a compiler to turn source code into machine-readable code, also known as machine-level language. The machine-level code is created by the compiler in a certain format so that the CPU can easily understand it and execute it without error. The way that machine-level languages are constructed varies depending on the operating system and programming language. For instance, if two PCs are using different operating systems, c/c++ creates.exe files that are distinct for each machine. You will get a clear idea of what is platform independent.
The way that machine-level languages are constructed varies depending on the operating system and programming language. For instance, if two PCs are using different operating systems, c/c++ creates.exe files that are distinct for each machine. And this is where the issue is! Unless both computers run on the same operating system, we cannot run code that has been built in one machine in another when a machine-level language differs by each operating system. Many developers and programmers think this is terrible.
Java is Platform Independent
What happens then when we compile Java code?
When we type the command “javac filename.java” or compile java code, javac performs the compilation. Additionally, Byte Code, an intermediate code, is produced. Because bytecode is platform-agnostic, it gives Java the crucial property of independence and portability. Tasks are made easier by this dependence since it requires less planning and translation to utilize in a variety of situations.
Java distinguishes itself from all other programming languages in this area. It generates what is referred to as byte code, or a.class file. When compiled, languages like C and C++ produce natively executable code, making them platform-dependent. Hold on—too it’s soon to celebrate. This byte code cannot be run. For this byte code to be executed, a translator is required. JVM performs this function. JVM often sits in our computer’s main memory. After acting as an interpreter, the Java Virtual Machine executes the bytes produced by javac.
We are finished, and our code has successfully run. So how will Java handle it on its own? And the JVM is to blame, would be the response. Although the byte code produced by source code compilation is operating system independent, the JVM installed on a machine varies depending on the operating system. Java is regarded as a platform-independent programming language in this way. Let’s first examine the architecture and operation of the JVM in order to properly comprehend it.
The JVM, which is a component of the Java runtime environment, transforms.java files into.class files. The main function in the source code is called by JVM when we compile Java code. The Java Virtual Machine (JVM) serves as a run-time engine for Java programs. The JVM is the one that actually invokes a Java program’s main function. JRE incorporates JVM (Java Runtime Environment). Java programs are referred to as WORA (Write Once Run Anywhere. The JVM consists of three distinct components: ClassLoader. Runtime Memory/Data Area. Execution Engine.
It belongs to the Java virtual machine as a subsystem. It loads the. class file, checks for errors, and is the cause of a small number of runtime exceptions. After verifying, it allows memory for the variables and methods that are present, gives variables and arrays default values, etc. Additionally, it runs any static variables or methods that are present in the code.
The class loader is designed to handle the task, therefore the Java runtime is not necessarily expected to be aware of the file and its systems when the classes are loaded.
Bootstrap classloader, Extension classloader, and Application classloader are the three built-in class loaders in JVMm.
- Bootstrap Classloader- Loads the libraries of Java.
- Extension Classloader- Load the codes in the directories of extensions or any other directory commanded by the system property.
- Application Classloader- Loads code found on java.class.path eventually mapping these java.class.path to CLASSPATH environment variable.
Memory Areas in JVM
Class names, method names, and variable names are among the data it keeps. It serves as a common resource for all the variables and methods in a class. It functions as a memory that holds data necessary to finish the task. It is shared across all threads of the virtual computer. The computation will determine if it is a fixed or extendable size.
It keeps track of all the data that is kept in the heap area. It keeps the data in a specific quantity that won’t be known until the program has been executed. It is utilized all through the program. It is used for the allocation of dynamic memory. In the heap region, new items are created. In a Heap, a unique type of tree-based data structure, the tree is a full binary tree. Heaps often come in two varieties: Max-Heap: A Max-Heap requires that the root node’s root key rank highest among all of its children’s root keys.
JVM Language Stack
When a function is called, it keeps the current information in blocks also known as stack-frames or frames, maintains local variables, and is heavily involved in thread management. Similar to the stack in a traditional language like C, a Java Virtual Machine stack is used for method invocation and return as well as holding local variables and partial results. Frames may be heap allocated since the Java Virtual Machine stack is never directly changed outside of pushing and popping frames.
The address of the instruction that is presently being executed is stored there. It is helpful when there are several threads being executed. A register called the program counter (PC) controls the memory location of the instruction that will be executed next. Each time an instruction is performed, the address supplied by the PC will be + n (+1 for a 1-word instruction and +2 for a 2-word instruction).
Native Method Stack
It keeps track of all the details of the local techniques employed. It has access to system-specific features that Java does not have direct access to. This project’s primary goal is to increase system performance through memory-level communication. The PC Register has a set size and is a very modest data space. The content and size have no bearing on Java apps. 2. To aid in the execution of native (non-Java) methods, a Native Method Stack is utilised. It stores data items similarly to a JVM Stack.
The execution engine will run the byte code, and it will release the memory allotted to any inaccessible or unreferenced objects. By reading the byte code in a stream and interpreting it to line by line, the interpreter in the execution engine will execute it. It also features a fascinating feature called JIT compiler (Just In Time Compiler), which generates native executable code for methods so that the JVM doesn’t have to interpret them twice if there are repeated function calls. As a result, execution performance is enhanced.
Native Method Interface
Java interacts with programs written in other languages, such as C/C++, via this interface. The interaction is two-way; either the programs themselves or the JVM may call one another. Due to the system-specific application of code, it has limited portability. It makes it easier for native code (written in C or C++) to interface with other programs ( written in Java or other programming languages). Additionally, this is what gives Java platform independence. A native programming interface is the JNI. It enables interaction between Java code and programmes and libraries created in other programming languages, such as C, C++, and assembly, when running inside a Java Virtual Machine (VM).
Native Method Libraries
It maintains track of any native language libraries that the execution engine could utilize. They are categorized as a collection of programs created for a certain architecture. These files are platform-specific.
Let’s resume our conversation now that we are aware of the JVM’s architecture. The result produced by those JVMs will be the same for the same byte code input, even though this JVM is different for various operating systems. Libraries created in other programming languages, such as C, C++, and assembly, are known as native method libraries. Through JNI, these libraries may be loaded.
We have covered how Java’s platform is independent in this article. We’ve gone over a number of Java’s special features, and learned what occurs when C/C++ programs are compiled and differentiated between byte code and natively executable code. We’ve discussed the justification for java’s platform freedom and come to the conclusion that the JVM is what makes java so flexible. In order to grasp it better, we looked at the JVM architecture. It must be evident now that Java is platform dependent or independent after reading this article. If you are interested to learn new coding skills, the Entri app will help you to acquire them very easily. Entri app is following a structural study plan so that the students can learn very easily. If you don’t have a coding background, it won’t be a problem. You can download the Entri app from the google play store and enroll in your favorite course.