Posts by Tag

JDBC is an API for connecting and executing queries on a database. Relatively low-level, it’s the foundation of most ORMs and other high-level data access l...

Java Constructors 101

The method that constructs your object.

JDBC 101-ish

JDBC is an API for connecting and executing queries on a database. Relatively low-level, it’s the foundation of most ORMs and other high-level data access l...

Debug a SQL performance issue (aka, how to read a query plan)

aka, how to read a query plan

Returning JSON in Spring Boot

Converting Json in Spring projects.

Spring Data JPA Basic

Additional capabilities beyond core spring and JPA.

Returning JSON in Spring Boot

Converting Json in Spring projects.

JSON Manipulation with Javascript

{“quote”:”You miss 100% of the shots you don’t take.”,”author”:”Wayne Gretzky”}

Set up and Run Junit in a Java project

Set up and Run Junit in a Java project.

Returning JSON in Spring Boot

Converting Json in Spring projects.

Upgrade A Spring Boot Project from 2.0 to 2.1

Upgrade Java, Spring Boot, Gradle, Flyway, etc.

Java Enum and How to Persist It

Should use Enums any time you need to represent a fixed set of constants

Java Bean VS Spring Bean

A Java object can be a JavaBean, a POJO and a Spring bean all at the same time.

Spring OAuth2 Notes

Spring OAuth2 101

Java Long Value Cacheing

The cache size may be controlled by -XX:AutoBoxCacheMax=<size> option.

Spring Data Management in Spring Certification

Spring Data Management in Spring Professional Certification (16%).

Integrate Spring Boot and Angular

Setup a project with Spring Boot and Angular.

Opinionated Final Variables in Java

I use final whenever it is appropriate.

Concatenating Java Strings

Behavior of String literals is very confusing.

Why Some Code Needed To Be Synchronized

I found one of my old notes… But still need to do more investigation. // todo

HashMap 101

HashMap is fast.

JSON Manipulation with Javascript

{“quote”:”You miss 100% of the shots you don’t take.”,”author”:”Wayne Gretzky”}

Jest, Javascript unit testing

Unit Testing in JavaScript

Parsing JSON using jq

Parse JSON using jq in the bash command line.

Add CloudWatch Alarms to A Lambda Function

Better monitoring your app.

Use AWS X-Ray in Lambda

Identify performance bottlenecks

AWS Lambda with Java

some lambda related concepts

Searching Text Using grep in Linux

How to search text in your files in Linux?

Filenames That Cross Platforms

The most conservative file naming conventions provide the most cross-platform compatibility.

Linux System Load Average Explained

Load Avg: 2.56, 2.26, 2.14

Don’t Use PHP in JS Condition Check

// todo

Use cURL to Transfer Data

cURL is a command line tool for getting or sending files using URL syntax.

Vim Editor 101

How to quit vim? - -!

Lombok in Spring

Lombok makes Java prettier, and your life easier.

Quarkus API First Development

With Swagger Open API

Spring Testing in Spring Certification

Spring test in Pivotal Spring professional certification (4%).

Mockito Basic

“Once,” said the Mock Turtle at last, with a deep sigh, “I was a real Turtle.” —Alice In Wonderland, Lewis Carroll

Create Couch Views in Spring

CouchDB is one of NoSQL database, uses JSON to store data, Javascript as its query language using MapReduce, and Http for an API.

Spring OAuth2 Notes

Spring OAuth2 101

How to Pass OCAJP Swiftly

I have no idea. It takes efforts.

Prepare for OCAJP, (6)

Exceptions.

Prepare for OCAJP, (5)

Design classes.

Prepare for OCAJP, (4)

Methods and Encapsulation.

Prepare for OCAJP, (3)

String and some common APIs.

Prepare for OCAJP, (2)

Java Operators and Statements.

Prepare for OCAJP, (1)

Java Building Blocks.

Concatenating Java Strings

Behavior of String literals is very confusing.

Build A 360 Photo View Page

Handle and view a 360 photo.

How to Debug PHP Code

There must be a better way. But this is the one I’m currently using.

Debug a SQL performance issue (aka, how to read a query plan)

aka, how to read a query plan

Use Embedded PSQL in Quarkus Integration Testing

// todo

How to Insert a Column in PostgreSQL

Insert (not add) a column in PostgreSQL is quite a mission.

Everyday PSQL Commands

PostgreSQL Cheat Sheet.

Use Embedded PSQL in Quarkus Integration Testing

// todo

Quarkus API First Development

With Swagger Open API

Debug a SQL performance issue (aka, how to read a query plan)

aka, how to read a query plan

Pure React Study Notes

Learn some React basics.

Pass AWS SAA Certification, SAA-C01

AWS Certified Solutions Architect - Associate, SAA-C01

AWS Servcies - Monitoring

CloudWatch, cloutTrail, etc.

AWS Servcies - Security

Cognito, IAM, KMS, IDF, etc.

AWS Servcies - Databases

RDS, Aurora, DynamoDB, ElastiCache, DMS, EMR, Kinesis, etc.

AWS Servcies - Networking &CDN

VPC, CloudFront, Route 53, ALB, etc.

AWS Servcies - Storage

S3, Glacier, EBS, Stoarage Gateway, SnowX, etc.

AWS Servcies - Compute

EC2, Auto Scaling, ELB, Serverless, EB, ECS, CloutFormation, etc.

AWS Key Concepts

AWS SAA: Key Concepts

AWS Services Study Notes, Integration

SNS, SQS, etc.

AWS Lambda with Java

some lambda related concepts

AWS SDK for Java 101

Build Java application with AWS services

Delete and Create Records Violates Constraints in Spring Data Jpa

Still haven’t found a decent answer in StackOverFlow.

Migrate SSRS Reports to Another Server

Watch my Youtube video to get details!

SQL Server Configuration

These are my notes while using SQL Server 2016.

Understanding SQL Server Connection Strings

SQL Server Connection Strings.

Spring Scheduled Tasks Stop Working

Investigate and fix stopped @Scheduled methods in Spring.

Servlet Container and Spring Framework

Servlet Container vs. Spring Containers (not finished yet)

Validations in Spring

Spring integrates Bean Validation and gives you more

Spring Scheduled Tasks Stop Working

Investigate and fix stopped @Scheduled methods in Spring.

Document APIs using Swagger

Use Swagger to document Spring boots porject’s APIs

Got Spring Professional Certificated at Aug 2019

Spring Boot Security 5 Basic

Powerful and highly customizable authentication and access-control.

Java Bean VS Spring Bean

A Java object can be a JavaBean, a POJO and a Spring bean all at the same time.

Session is Lost in Session Scope Controller in Spring MVC App

Why is my session lost and created as new in every servlet request?

Spring Security in Spring Certification

Spring Security in Pivotal Spring Professional Certification (6%).

Spring OAuth2 Notes

Spring OAuth2 101

Spring RestTemplate

Spring RestTemplate 101.

Delete and Create Records Violates Constraints in Spring Data Jpa

Still haven’t found a decent answer in StackOverFlow.

Spring Testing in Spring Certification

Spring test in Pivotal Spring professional certification (4%).

Mockito Basic

“Once,” said the Mock Turtle at last, with a deep sigh, “I was a real Turtle.” —Alice In Wonderland, Lewis Carroll

Spring REST in Spring Certification

Spring REST in Pivotal Spring professional certification (6%).

Spring MVC in Spring Professional Certification

Spring MVC in Pivotal Spring professional certification(8%).

Spring Data Management in Spring Certification

Spring Data Management in Spring Professional Certification (16%).

Spring AOP in Spring Certification

Spring AOP in Spring Certification(8%).

Spring Boot in Spring Professional Certification

Spring Boot in Pivotal Spring professional certification (32%).

Spring Core in Spring Certification

Spring Core in Spring Certification (20%).

Lombok in Spring

Lombok makes Java prettier, and your life easier.

Setup a simplest Spring Project Demo Project

A Spring Demo project. See: https://github.com/digitalsonic/geektime-spring-family

Create Couch Views in Spring

CouchDB is one of NoSQL database, uses JSON to store data, Javascript as its query language using MapReduce, and Http for an API.

Spring AOP in Spring Certification

Spring AOP in Spring Certification(8%).

Servlet Container and Spring Framework

Servlet Container vs. Spring Containers (not finished yet)

Document APIs using Swagger

Use Swagger to document Spring boots porject’s APIs

Got Spring Professional Certificated at Aug 2019

Spring Boot Security 5 Basic

Powerful and highly customizable authentication and access-control.

Mockito Basic

“Once,” said the Mock Turtle at last, with a deep sigh, “I was a real Turtle.” —Alice In Wonderland, Lewis Carroll

Spring Boot in Spring Professional Certification

Spring Boot in Pivotal Spring professional certification (32%).

Integrate Spring Boot and Angular

Setup a project with Spring Boot and Angular.

Returning JSON in Spring Boot

Converting Json in Spring projects.

Setup a simplest Spring Project Demo Project

A Spring Demo project. See: https://github.com/digitalsonic/geektime-spring-family

Spring Core in Spring Certification

Spring Core in Spring Certification (20%).

Spring Data Management in Spring Certification

Spring Data Management in Spring Professional Certification (16%).

Java Enum and How to Persist It

Should use Enums any time you need to represent a fixed set of constants

Delete and Create Records Violates Constraints in Spring Data Jpa

Still haven’t found a decent answer in StackOverFlow.

Spring Data JPA Basic

Additional capabilities beyond core spring and JPA.

Session is Lost in Session Scope Controller in Spring MVC App

Why is my session lost and created as new in every servlet request?

Spring RestTemplate

Spring RestTemplate 101.

Spring MVC in Spring Professional Certification

Spring MVC in Pivotal Spring professional certification(8%).

Got Spring Professional Certificated at Aug 2019

Spring Security in Spring Certification

Spring Security in Pivotal Spring Professional Certification (6%).

Delete and Create Records Violates Constraints in Spring Data Jpa

Still haven’t found a decent answer in StackOverFlow.

Spring REST in Spring Certification

Spring REST in Pivotal Spring professional certification (6%).

Spring MVC in Spring Professional Certification

Spring MVC in Pivotal Spring professional certification(8%).

Spring AOP in Spring Certification

Spring AOP in Spring Certification(8%).

Spring Boot in Spring Professional Certification

Spring Boot in Pivotal Spring professional certification (32%).

Spring Core in Spring Certification

Spring Core in Spring Certification (20%).

Spring REST in Spring Certification

Spring REST in Pivotal Spring professional certification (6%).

Spring Boot Security 5 Basic

Powerful and highly customizable authentication and access-control.

Spring Security in Spring Certification

Spring Security in Pivotal Spring Professional Certification (6%).

Spring OAuth2 Notes

Spring OAuth2 101

Spring Testing in Spring Certification

Spring test in Pivotal Spring professional certification (4%).

Spring Boot Security 5 Basic

Powerful and highly customizable authentication and access-control.

Upgrade A Spring Boot Project from 2.0 to 2.1

Upgrade Java, Spring Boot, Gradle, Flyway, etc.

Delete and Create Records Violates Constraints in Spring Data Jpa

Still haven’t found a decent answer in StackOverFlow.

What I Did After Updating Database by Mistake?

So sorry that I falsely updated the database with the following script:

Quarkus API First Development

With Swagger Open API

Document APIs using Swagger

Use Swagger to document Spring boots porject’s APIs

Unit Test Terms

Terms using in Unit Tests.

Learn Test-Driven Development (TDD) from Uncle Bob

The jury is in. The controversy is over. The debate has ended. The conclusion is: TDD works.

Set up and Run Junit in a Java project

Set up and Run Junit in a Java project.

Set up and Run Junit in a Java project

Set up and Run Junit in a Java project.

Types of Software Testing

Test makes perfect.

Converting Date Time in Java

Unit Test Terms

Terms using in Unit Tests.

Spring Testing in Spring Certification

Spring test in Pivotal Spring professional certification (4%).

Mockito Basic

“Once,” said the Mock Turtle at last, with a deep sigh, “I was a real Turtle.” —Alice In Wonderland, Lewis Carroll

Learn Test-Driven Development (TDD) from Uncle Bob

The jury is in. The controversy is over. The debate has ended. The conclusion is: TDD works.

Jest, Javascript unit testing

Unit Testing in JavaScript

Vim Editor 101

How to quit vim? - -!

Thinking in jQuery

jQuery, live long and prosper!

Filenames That Cross Platforms

The most conservative file naming conventions provide the most cross-platform compatibility.

Use AWS X-Ray in Lambda

Identify performance bottlenecks

Use cURL to Transfer Data

cURL is a command line tool for getting or sending files using URL syntax.

How to Insert a Column in PostgreSQL

Insert (not add) a column in PostgreSQL is quite a mission.

Everyday PSQL Commands

PostgreSQL Cheat Sheet.

NPM Semantic Versioning

We should tag projects like NPM does.

Searching Text Using grep in Linux

How to search text in your files in Linux?

Convert unit between metric and imperial in Java

Unit convertion, e.g., Metric to imperial

Thinking in jQuery

jQuery, live long and prosper!

Parsing JSON using jq

Parse JSON using jq in the bash command line.

Linux Basic Commands for Files and Directories

Essential commands to manipulate files and directories on Linux.

NPM Semantic Versioning

We should tag projects like NPM does.

Moss GU

Posts by Tag

360 Photo

API

AWS

Alarm

Angular

ApiGateway

Bash

Bean Validation

CDK

CSS

Cloud

CloudFormation

CloudWatch

CouchDB

Curl

Cypress

Database

Date

Date Time

Docker

E2E testing

Enum

FORM

Flex

Flyway

Gradle

HTML

Hibernate

IDE

IaC

Integration Testing

IntelliJ

JAVA

JDBC

JOOQ

JPA

JSON

JUnit

Jackson

Java

Javascript

Json

Lambda

Linux

Lombok

Maven

Mockito

NoSQL

OAuth2