5 days ago

Storage and Retrieval: Memory Search and Indexing (Java-focused)

Java Memory Management — Java has automatic memory management that automatically performs garbage collection, which auto-release objects that are no longer in use to free up memory. Java Memory Structure Stack: primitive types (int, char, …) and holds a reference to heap objects. Heap: actual objects, objects store their value inside the heap. Algorithm Complexity

Java

1 min read

Storage and Retrieval: Memory Search and Indexing (Java-focused)

Java Memory Management

Java has automatic memory management that automatically performs garbage collection, which auto-release objects that are no longer in use to free up memory.

Java Memory Structure

Stack: primitive types (int, char, …) and holds a reference to heap objects.
Heap: actual objects, objects store their value inside the heap.

Algorithm Complexity

5 days ago

Batch Processing and Stream Processing (Async & Sync Messaging)

Batching Processing (Offline System) Takes a large amount of input data and uses a background job to process them in a batch, and then sends it out maybe the next day Fault tolerance—failed tasks will be recalled and re-executed Idempotent operations—multiple executions of a job only perform once. Common examples…

Batch Processing

3 min read

Jun 23

Overview — Memory v.s. Disk & Files System & I/O Operation (Java)

Memory v.s. Disk Memory: fast access, small size, temporary storage Disk: slow access, large size, permanent storage Performing an operation inside memory is very fast but very expensive due to its limited memory. …

File Storage

2 min read

Overview — Memory v.s. Disk & Files System & I/O Operation (Java)

Jun 22

Concurrency — in a Multi-Threaded Environment (Thread Concepts and Locks)

Thread is the smallest unit of execution scheduled by OS. A task is a work that is performed by a thread. A process is a set of threads that execute in the same shared environment. Executing multiple threads or processes at a time is called concurrency. Multi-thread programming is doing…

Java

3 min read

Concurrency — in a Multi-Threaded Environment (Thread Concepts and Locks)

Jun 16

Software Testing Overview — Unit Testing

Any test is composed of 3 parts: Prerequisites that are needed The expectation of what the result should be Trigger to make the call that will be tested A rough example using RSpec — A testing library for Ruby subject { described_class.process(data: data) } let(:id) { 123456 } describe '#process'…

Testing

5 min read

May 14

Object-Oriented Programming (OOP)

A Quick Overview of the OOP Concept — What Is Object-Oriented Programming? Class is an abstract blueprint (the source of the plan) used to instantiate more specific, concrete objects based on that blueprint. Use objects to represent things you are programming about, variables as properties, and functions as methods. Creates an object, so the object is the implementation of the class that…

Oop

2 min read

Jul 31, 2021

Basic Data Structures in Java— Arrays, Lists, Sets, Queue, and Maps

I will cover the data structures including Arrays, Lists, Sets, Queues, and Maps here. Depending on whether the order of items matters, how items are sorted, and whether the list can contain duplicates, we can choose the suitable collection type that fits our needs. Data Structure is a collection of…

Java

5 min read

Jul 24, 2021

Exception Handling Options in Java

Why is exception handling useful? Exception handling is useful, it allows the program to keep running in the desired flow while an unexpected exception occurs, and gives the option to provide a user-friendly message to tell the user what is going on with the exception. …

Java

2 min read

Jul 21, 2021

The Differences Between Java v.s. JavaScript

Java and JavaScript are different, just like ham and hamster are different too. Java is an object-oriented programming language that performs tasks based on the relationship between objects that executes in a Java virtual machine, while JavaScript is an object-oriented scripting language that does not require a compiler, it runs…

Java

3 min read

Jul 17, 2021

Abstract Classes v.s. Interfaces in Java

A MUST-KNOW CONCEPT FOR JAVA INTERVIEW!!! Look at both Abstract Classes and Interfaces as a set of rules that defines behavior that a class must support, like a contract when inheritance. Whereas, abstract classes generalize behavior (from general to specific) while interfaces standardize behavior. Abstract Classes - it cares where…

Java

2 min read