todo

https://javarevisited.blogspot.com/2018/07/top-9-java-programming-books-best-must-read.html
https://www.stackchief.com/

some examples are in java 8

1.kafka-example

uninstall/install

	https://linuxhint.com/uninstall-java-ubuntu/

	https://linuxhint.com/install_oracle_jdk11_ubuntu/
	https://www.rosehosting.com/blog/how-to-install-java-17-lts-on-ubuntu-20-04/

installing openjdk 11

    download tar file
    extract to opt folder
    mithun@localhost:~/Downloads$ sudo tar -xzf openjdk-11_linux-x64_bin.tar.gz -C /opt
    set home
    mithun@localhost:/opt$ export JAVA_HOME=/opt/jdk-11/
    set path
    mithun@localhost:/opt$ export PATH=$PATH:$JAVA_HOME/bin

two option : set java globally or locally

    globally : no need to set java path locally
		login to rootuser
		sudo -
		password : mithun123
		# create gedit file
		put JAVA_HOME and PATH variables in file openjdk.sh
		save openjdk.sh in folder "etc/profile.d"

Locally : 
            in home folder , there is a hidden file called .profile, set java path in this file
	mithun@linux:~$ gedit ~/.profile
	above command opens .profile in gedit
	add path as mentioned below
		
	export JAVA_HOME=/opt/jdk-11/
	PATH="$HOME/bin:$HOME/.local/bin:$PATH:$JAVA_HOME/bin"


	# check java version
	mithun@linux:~$ source .profile
	mithun@linux:~$ java -version
	# source command to load file again to reflect changes        

set java path in bashrc

	home> sudo nano ~/.bashrc
	 
	export JAVA_HOME=/opt/jdk-11/
	export PATH="$HOME/bin:$HOME/.local/bin:$PATH:$JAVA_HOME/bin"

set java path for eclipse

    open eclipse.ini file
    set below command before vmargs
    ##
            -vm 
            /opt/jdk-11/bin/java
    ##

source video : https://www.youtube.com/watch?v=TaIzZU28xVs

concurrency vs parallelism

concurrency : shared data bw threads : synchronisation
parallelism : no shared data bw threads : sync not required

tutorials

https://www.javainuse.com/spring/sprboot
https://bezkoder.com/
https://github.com/javadevjournal/javadevjournal
https://github.com/roytuts/spring-boot
https://github.com/darbyluv2code/fullstack-angular-and-springboot  
https://github.com/darbyluv2code/spring-and-hibernate-for-beginners
https://www.javaguides.net/
https://knpcode.com/
https://github.com/lokeshgupta1981
https://github.com/lokeshgupta1981/Spring-Boot3-Demos
https://zetcode.com/all/#java
	https://www.youtube.com/watch?v=ybQAmFsVQqA : maven : multi module and plugins

algorithms

https://github.com/TheAlgorithms/Java

watch

https://blogs.oracle.com/javamagazine/
https://bezkoder.com/
https://github.com/javadevjournal/javadevjournal
https://github.com/BruceEckel/OnJava8-Examples

to learn

	 Multithreading concepts to learn.
	-> Runnable, Callable
	-> Futures
	-> Join
	-> Locks
	-> Race conditions
	-> Deadlock
	-> thread dumps
	-> Concurrency utilities
	-> volatile
	-> Java memory model

explore

https://github.com/Apress
    https://github.com/PacktPublishing
https://github.com/thombergs/code-examples
https://www.java4s.com/