Artur Ashyrov
Head of Engineering
Intro. Toolkit setup. IDE/VCS
- JDK, JRE, JVM, bytecode, compiling vs interpreting
IDE: Idea
VCS: Git, GitHub, GitLab, Bitbucket - Creating git repos.
CloningBasic git flow: commit/push/fetch/pull
Branches: merging, pull requests, tags
Java 101: hello world
- Java Basic Syntax, comments, classes, methods, entry point, HelloWorld App
Data types, sizes, static vs dynamic typing, min and max, default values
Java command line - Maven, dependencies
Compiling, running, testing from command line - Conditionals, ternary operator, switch (+break), readability switch vs if
Iterations: for / while / do while
Enums. Limited set of values. impossibility to represent incorrect values - Arrays, declarations
Finding a value, sorting, copying, slicing
Passing as a parameter, returning as a result - Strings. Basic operations
Immutability, StringPool
Java OOP
- OOP intro - split declaration, instantiation (object creation) and behavior
Java modifiers: private, public, protected, package private
Encapsulation, polymorphism, interfaces, nested classes - Object Equality
Equals, hashcode, relations between them, Lombok
Custom equality, know your data! Write proper hashcode
Java Exceptions
- Exceptions
Errors, Checked, Unchecked, try / catch / finally syntax
How to deal, where to catch. try / catch with resources
Java collections
- Collections, basic types, basic operations
List, Set
Generics idea, primitive wrappers, boxing / unboxing, Power and Limitations, Type erasure - Linked List
Stack, Queue - Set, Map, unique, absence of ordering, common behavior
Common usecases
Iteration over Set and Map - Comparator / Comparable
Iterator / Iterable
Sorting with custom comparator
Streams and Functions
- Streams
Combining, Splitterator
Parallelism - lambda syntax, method reference, constructor reference
Functional Interfaces, high-order functions
Optional type
Java misc: IO, working with date&time, annotations
- Java reflection, annotations
Custom annotation writing and processing
Complexity & caveats - Input / Output Streams, Readers, Writers
File operations. Reading/Writing files
IOException - Java8 DataTIme API
Instant, LocalDataTime
Parsing, formatting
Java Multi-threading
- Multithreading. Problem
Threads model in Java
Different abstraction levels: synchronization, volatile - Java memory Model, primitives vs referential, classes vs objects
ClassLoader / stack / heap, null as a reference to nothing
Static examples, patterns, antipatterns, Garbage Collection - Concurrent primitives: Barriers, Latches, Locks
Concurrent Data Structures: Atomic*, ConcurrentCollections
Future, CompletableFuture, Executors, ExecutorPools
Working with databases: SQL&NoSQL
- SQL abstraction, syntax
PostgreSQL: creating database in PGAdmin
Select, insert, update, delete, where - Join: left, right, inner, outer, full
Aggregation: count, min, max, avg, sum
Nested queries, constraints, primary, foreign keys - NoSQL vs SQL dbs
Elasticsearch
Neo4J - JDBC connection, statement
JDBC resultSet
JDBC transactions
Working with HTTP
- HTTP Server, URL, URI, Servlet, Request, Response, Lifecycle
Mappings, GET, POST, Parameter passing. Redirects
Tomcat app server - Serialization
XML, JSON
Jackson library - REST principles
conventions: verb/noun, signular/plural
API versioning
Design patterns: basics
- Design patterns. Generative, structural, behavioral
Generative patterns: factory, builder
Structural patterns: facade, proxy - Dependency Injection
MVC
DAO: InMemory / File / SQL Implementations
Spring Boot
- Spring framework
Spring Beans
Spring Dependency Injection - Spring Boot
Bootstrap file vs application yml
Overriding parameters in boot app - View vs Data, Controller vs RestController
Mappings
Parameters/Entities passing - Exception Handling
ControllerAdvice
Application-wide error handling, custom 40X,500 - SpringData. CrudRepo, PagingAndSortingRepo, JpaRepo
DTO Pattern, findByExample, ModelMapper
H2 for testing - Database migration. Necessity of metadata manage
Basic Examples
FlyWay - Spring Boot Test
Writing integration tests
Mocking beans
Algorithms. Recursion. Complexities
- Algorithms. Complexity
N vs LogN difference - Algorithms. Recursion
Length, count, factorial, fibonacci
Head recursion vs tail recursion - Algorithms. Linked Lists
Merging two sorted lists
Add/remove by index/value - Algorithms. Binary search
Recursive / non-recursive
Position to insert missing item
Java + DevOps: CI/CD
- ci-cd: concept, problems, solutions
ci-cd: .gitlabci.yaml, runners, services, building docker images
ci-cd: gitlabci: stages - ci-cd: gitlabci: build\publish docker image
Java + DevOps: Docker
- Linux process abstraction
virtualization history. virtualization vs isolation. vm vs container, docker
docker concepts: container, image, layers, network, volumes - docker install on Linux, macOS
build docker image: Dockerfile, build command
docker registry: pull, push - main docker commands: build, run exec
docker compose: concept, network, volumes
docker compose: multicontainer examples
Java + DevOps: K8S
- k8s: concepts, problem, solution
k8s: control plane, data plane, components, architecture
k8s: resources: node, pod, service, deployment, ingress - k8s: katacoda
k8s: minikube
k8s: k3s
Java + DevOps: Monitoring
- best practices: cloud-native apps
k8s - startup, liveness,readiness probes, handling sigterm - telemetry - prometheus overview
exposing metrics - jmx
stafanprodan/podinfo overview
