Md Jamilur Rahman jamilxt

Kafka Distributed Streaming Platform

Publish and Subscribe / Process / Store

Start Kafka

Kafka uses ZooKeeper as a distributed backend.

Start Zookeeper

Background story

It is a common scenario that we often forget out database password. When we try to log in to our mysql DB, we face the following error message. If we use a password:

ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)

If we don't use a password:

ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)

Core Java

Chapter 0 : Fundamentals

Data Types and Variables - https://www.baeldung.com/java-primitives
Access Modifiers - https://www.baeldung.com/java-access-modifiers
If-Else
Loops - https://www.baeldung.com/java-loops
OOP Concepts - https://www.baeldung.com/java-oop

Project Generator

https://github.com/VeryGoodOpenSource/very_good_cli (It will nicely genearate a project with all the basic setup, but with bloc state management, you can simply replace with any other state management library)

State Management

Riverpod or Bloc

RiverPod: https://pub.dev/packages/riverpod
Bloc: https://pub.dev/packages/flutter_bloc

	// Create new configuration that specifies the error correction
	Map<EncodeHintType, ErrorCorrectionLevel> hints = new HashMap<EncodeHintType, ErrorCorrectionLevel>();
	hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);

	QRCodeWriter writer = new QRCodeWriter();
	BitMatrix bitMatrix = null;
	ByteArrayOutputStream baos = new ByteArrayOutputStream();

	try {
	// Create a qr code with the url as content and a size of 250x250 px

	# Backup
	docker exec CONTAINER /usr/bin/mysqldump -u root --password=root DATABASE > backup.sql

	# Restore
	cat backup.sql \| docker exec -i CONTAINER /usr/bin/mysql -u root --password=root DATABASE

	import java.io.ByteArrayInputStream;
	import java.io.File;
	import java.io.FileInputStream;
	import java.io.FileNotFoundException;
	import java.io.FileOutputStream;
	import java.io.IOException;
	import java.io.InputStream;
	import java.io.OutputStream;
	import java.io.UnsupportedEncodingException;

	// Find the View that shows the numbers category
	TextView numbers = (TextView) findViewById(R.id.numbers);

	// Set a click listener on that View
	numbers.setOnClickListener(new View.OnClickListener() {
	// The code in this method will be executed when the numbers View is clicked on.
	@Override
	public void onClick(View view) {
	Intent numbersIntent = new Intent(MainActivity.this, NumbersActivity.class);
	startActivity(numbersIntent);

	import org.junit.Test;
	import org.junit.runner.RunWith;
	import org.master.Application;
	import org.springframework.beans.factory.annotation.Value;
	import org.springframework.boot.test.IntegrationTest;
	import org.springframework.boot.test.SpringApplicationConfiguration;
	import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
	import org.springframework.security.oauth2.client.DefaultOAuth2ClientContext;
	import org.springframework.security.oauth2.client.OAuth2RestTemplate;
	import org.springframework.security.oauth2.client.token.grant.client.ClientCredentialsResourceDetails;

	package demo;

	import java.io.Serializable;
	import java.util.ArrayList;
	import java.util.Collection;
	import java.util.Collections;
	import java.util.HashMap;
	import java.util.HashSet;
	import java.util.LinkedHashMap;
	import java.util.List;