Java Base64 URL Safe Encoding

When it comes to common tooling in Java, Guava is your best friend. If you are still using Apache Commons, stop now. Below is the gradle dependency information for guava as of this writing.

compile 'com.google.guava:guava:18.0'

Base64 URL Safe Encoding

Here is a simple example of encoding text with Base64 with Guava.

import com.google.common.io.BaseEncoding
import com.google.common.base.Preconditions

public class UrlSafeEncodingExample {

  public static void main(String[] args) {
    Preconditions.checkNotNull(args);
    Preconditions.checkNotNull(args[0]);

    String decodedString = args[0];

    System.out.println("Decoded String: " + decodedString);

    String encodedString = BaseEncoding.base64Url().encode(decodedString.getBytes('UTF-8'));

    System.out.println("Encoded String: " + encodedString);
  }

}

Check out more about Guava in their git repository.

Microservices Tech Stack with Spring and Vert.X

It’s been awhile since my last blog post, and it’s been for several reasons. The primary, is that our team has been challenged to implement a Microservice Architecture (MSA) that fit’s my current company's needs. It’s been a process defining the stack, learning the new stack and providing tooling/components for developers to innovate.

Understanding Immutable Classes In Java

I recently reviewed an article that claimed immutable classes in Java are not always thread safe. Ultimately, this is not true since any immutable class cannot contain state and therefore no two threads could change it's state.
To understand this more, I would like to do a quick dive into what an Immutable class is in Java.

Yes, Immutable Means Thread Safe. It's that simple.

Plain and simple, IMMUTABLE IS ALWAYS THREAD SAFE, and it is a very simple concept. If somethings state cannot change upon instantiation, no two threads can ever write to the object and break it's state.

The other day I was curious what people thought about this topic. A top hit from DZone claimed not always, and I would like to rebuttal.

Here is a link. https://dzone.com/articles/do-immutability-really-means

And my response:

Spring HATEOAS - Embedded Resources with HAL

One common issue I see on the web is people having trouble rendering their JSON objects in HAL with embedded resources. For this example I am using groovy, but it explains how to configure the rendering of resources in a spring applicaiton.

Rails Unfit for Microservices?

This is a relatively informal blog post. Looking more for feedback and response to get a conversation started. The prerequisite to this thread is that you have a fairly good understanding of Microservices. If not at least read the following link:
http://martinfowler.com/articles/microservices.html

The Java Enum: A Singleton Pattern

The singleton pattern restricts the instantiation of a class to one object. In Java, to enforce this, the best approach is to use an enum. This great idea comes straight from the book Effective Java by Joshua Bloch. If you don't have it in your library, get it. One of the best Java books to date.

There are a few reasons why one would use an enum as a singleton in Java:

Bootstrap Guide: The Virtual Tour Library

Introducing a Virtual Tour Library (using TW Bootstrap)

Fork Or Download Project On Github

 A jQuery library used for designing help pages for your website. Gives the user a guided walk through of your webpage and it's functions.

Free Twitter Bootstrap Admin Theme

Introducing Responsive Clean Dashboard Bootstrap UI Theme

Java Developers Need To Be Using Lombok

Lombok is a Java library meant to simplify the development of Java code writing. This article deals with writing classes that need getters/setters, override equals, hashCode, toString and/or offer a copy constructor. Way to go Java! You just made writing a simple class cumbersome. Project Lombok will make your day if you haven't seen it yet.

Adding Groovy Sources to Maven Build Path

Say you want to run a groovy class method from your Java project in Maven. You've placed the script file at src/main/groovy/script/MyGroovyScriptClass.groovy. In Java, you would load the class and execute its method like so:

Ignore Header and Trailer Lines During Java InputStream Read

Ignore first + last lines in a file

After beating my head against the wall for some time, I was finally able to come up with a solution for this.

Say you want to hand off an InputStream or InputStreamReader to an underlying API. The problem is that your input stream may have a header or trailer. Those header/trailers differ from the underlying format. This is commonly true for CSV, EDI, and fixed length file types. So if you want a CSV file parsed by a Java API like the Smooks api, you will need to hand the framework an InputStream.

Grails Part 5 - Adding Basic Security

Click here to view the full tutorial

Continuing series: Developing a Grails Web Application.
Tutorial will: walk through steps of creating a robust Grails web application.
Application name: grails-mongo-demo
The Goal: To track and record persons addresses.

This application will use the Grails Framework to develop a web application using:
1. MongoDB
2. Spring Security
3. Apache CXF
4. Jetty Web Server
5. Maven build integration => Removed upon Request
Previous Post: Grails Part 4 - Enhanced UI Design w/ tw Bootstrap

View Project on Github

These Instructions Will Walk Through:

• Configuring Spring Security Plugin
• Adding static URL maps
• Bootstrapping in security data
• SecurityTagLib - Conditionally display gsp content
• Configure Security Pages with Twitter Bootstrap UI

Grails Part 4: Enhanced UI Design w/ Twitter Bootstrap

Click here to view the full tutorial

Continuing series: Developing a Grails Web Application.
This application will use the Grails Framework to develop a web application using:
1. MongoDB
2. Spring Security
3. Apache CXF
4. Jetty Web Server
5. Maven build integration => Removed upon Request
Previous Post: Grails Part 3 - Building a CRUD Application

View Project on Github

These Instructions Will Walk Through:

• Enhanced UI Design with tw bootstrap
• Configure Bootstrap with lesscss-resources plugin
• Adding a custom controller
• Customizing Scaffold Templates
• Improving Scaffold Output

Grails Part 3 - Building a CRUD Application

Click here to view the full tutorial

Continuing series: Developing a Grails Web Application.
This application will use the Grails Framework to develop a web application using:
1. MongoDB
2. Spring Security
3. Apache CXF
4. Jetty Web Server
5. Maven build integration => Removed upon Request
Previous Post: Grails Part 2 - Configuring the Plugins

View Project on Github: Grails MongoDB Demo

These Instructions Will Walk Through:

• Building a CRUD Application
  • Building the Domain Model
  • Controllers using Grails Scaffolding

Grails Part 2 - Configuring Web Application Plugins

Click here to view the full tutorial

Continuing series: Developing a Grails Web Application.
This application will use the Grails Framework to develop a web application using:
1. MongoDB
2. Spring Security
3. Apache CXF
4. Jetty Web Server
5. Maven build integration => Removed upon Request

Previous Post: Grails Part 1 - Setting up a Project on Maven With IntelliJ

View Project on Github: Grails MongoDB Demo

These Instructions Will Walk Through:

• Configuring the Plugins
  • MongoDB
  • Jetty
  • Spring Security
  • Apache CXF (WSClient)

Grails Part 1 - Setting up a Project

Click here to view the full tutorial

Continuing series: Developing a Grails Web Application.
This application will use the Grails Framework to develop a web application using:
1. MongoDB
2. Spring Security
3. Apache CXF
4. Jetty Web Server
5. Maven build integration

View Project on Github: Grails MongoDB Demo
These Instructions Will Walk Through:

• Installing the Grails SDK
• Project Setup
  1. Creating a Grails Application
  2. Integrating with Maven
  3. Integrating with IntelliJ

Applying the Strategy Pattern in Java

Working with strategy on Arrays.sort & java.util.Comparator

All these examples and more can be found on github

In Java, you cannot pass function references through a method. With this being true, how do we then apply a strategy to a method? What is suggested, is that we define an interface with the function we want to pass. This way we can on the fly, define and pass an algorithm to a method for process.

In this demo, we will be working strictly with the strategy interface: java.util.Comparator. This is a java strategy interface, readily available in the Java API as of 1.5. It supplies a compare algorithm, where its implementation is primarily for sorting large collections of objects.

Atmosphere Websockets & Comet with Spring MVC

Since writing this guide, Spring has come out with their own Comet and Websocket implementations. I suggest you first read through their guides before deciding on atmosphere as your Comet & Websocket solution.

1. Messaging with Stomp over Websockets
2. Spring Messaging

On to the guide...

Feel free to clone the source of this project on github.
springMVC-atmosphere-comet-websockets

The Websocket protocol is defined by W3C here. The protocol is considered an HTTP upgrade protocol. Essentially what happens is, a websocket request is made by a client browser, via the HTTP protocol. Once, the request is in, the server should respond with a success. Then the browser and server establish a TCP link to handle communication from there on out. This protocol enables bi-directional communication between a client and server. Here is a link to browser and servers that support Websockets and/or Comet: comet/websocket support link