Installing JDK + JRE

Installing Jetbrains

Setting Up Windows cmd For Java

Head First Java: One of the best Java book for beginners.

Core Java Volume 1: Covers both basics and advanced topics in Java, Highly recommened for those who are already familiar with Java.

The Complete Java Reference: Another great book covering basics of Java in crisp and concise manner.

Oracle Docs: Best resource for learning Java, all you have to learn is how to search the docs :P. Recommend for advanced users.

Java TPoint: Great online resource for learning Java concepts.

Bucky Roberts Video Series: Great youtube playlist to learn java in a fun manner.

Java is an object oriented, class-based, concurrent, secured programming language.

Initiators: James Gosling, Mike Sheridan, and Patrick Naughton

Features of java:

1. Write once run anywhere
2. Multithreated
3. Security
4. Built in graphics
5. Object Oriented language
6. Support Multimedia
7. Open product
8. Platform independent

Command to set temporary path in cmd

• set path=C:\Program Files\Java<jdk_folder_name>\bin

Compilation:

• Compile time

  • javac fileName.java
  • Class -> Compiler -> Bytecode

• Runtime

  • java fileName
  • classfile -> classloader -> bytecode verifier -> interpreter -> runtime -> hardware

JDK

• Compiler(javac), tools(javap, java) + JRE

JRE

• JVM + Euntime Environment
• Provide set of software tools which are used for developing Java applications.
• It is used to provide the runtime environment.
• JRE implements JVM.
• Since JRE is implementation of jvm therefore is also released by different other companies (openjdk, oraclejdk)

JVM

• Can run anything compiled to bytecode. It is a virtual machine.

• JVM is system dependent.

• Functions of JVM Loads code Verifies code Executes code Provides runtime environment

  therefore used to convert and run bytecode line by line. bytecode -> machine code -> run that line

• How JVM Works

• JDK vs JRE vs JVM

JIT

• line by line, hence --> performance problem -- (solution needed) --> jit
• Hepls java interpreter to run and execute code faster
• Refer this link
• Two observations firstly of repeated code segments, secondly wrongly written code.

Classes and Objects

• Refer the ppt for all the theory and examples
• this reference in Java
• instance vs static methods in java
• Refer this code for basic syntax and this code for Mutator Example