0Java is object-oriented, robust, multithreaded, distributed and dynamic language. It's platform independent and architecture independent language and hence portable. Feature WORA supports it means writing once and run everywhere. Means once the code is written and compiled in one system can be executed in any other order, i.e. o/s and processor. This feature of java brought revolution in the field of technology by supporting the Internet. It's used to develop different types of value application, i.e. Web Application, Mobile Application, Games, Desktop Application and playing value role in IoT. Nowadays in development technologies, Its importance is on top. It's open source and valuable to implement.
James Gosling develops it at Sun Microsystems Pvt Ltd, and that's why called Sun Java. Nowadays it's owned by Oracle Corporation.
It's both compiled and interpreted to support platform independent feature.
In first java source code is compiled by javac compiler and .class file is created called bytecode. In the next phase with interpreter java bytecode is interpreted and executed in JVM. Java interpreter is one of value component of JVM. Bytecode is loaded into JVM by class loader...
JDK is called Java development kit and is the complete software package to develop and deploy the application. It contains development and debugging tool. The developer uses this to create, debug and execute. It includes JRE and JVM inside. It is platform dependent.
JRE is Java runtime environment where bytecode executes. It is the implementation of JVM. It is also platform dependent. It is used by the client to run the application.
Hence accordingly JDK and JRE as per platform downloaded and installed by developer and client respectively.
JVM is called java virtual machine or abstract machine where bytecode executes in runtime. Its important components are ClassLoader, Memory Areas and Execution Unit.
All these will be more explained in the session.
Interview questions :
- Explain Java and importance in development.
- Explain why java is called platform independent?
- Explain oops concept.
- What is bytecode in Java? Explain importance.
- Explain the architecture of JVM.
- Explain class loader and types of losers.
- Explain memory areas of JVM.
- Explain JIT and importance in Java
- Explain Garbage collector and collection in Java
- Explain JDK, JRE and JVM.
