Spring

Many developers were burned by the overly complex world of Java back in the early 2000s. The Gang of Four patterns and middleware / J2EE / Java EE led to ridiculous levels of alleged decoupling as is evident in this sequence diagram from an open source J2EE ecommerce system I worked on in 2002:

Back in 2014 I wrote about how things had changed: Java Doesn’t Suck – You’re Just Using it Wrong.  But six years have passed since I wrote that and things have continued to improve, making the Java platform a fantastic option when building microservices, data pipelines, web apps, mobile apps, and more.  Let’s walk through some of the “modern” (as of 2021) aspects to the Java platform.

Broadly speaking there are two types of integrations with Salesforce, either a system-to-system integration or a user interface integration. One of the primary ways to do these integrations is by using the Salesforce REST API. When using the Salesforce REST API you need to obtain an access token that identifies who is making the requests. OAuth 2 provides an HTTP interface to obtain a Salesforce access token.

When using the Salesforce OAuth 2 API there are three options for obtaining an access token:

Great developer experiences allow you go from nothing to something amazing in under ten minutes. So I’m always trying to see how much I can minimize getting started experiences. My latest attempt is to deploy a Spring Boot app on Heroku, download the source to a developer’s machine, setup & run the app locally, make & test changes, and then redeploy those changes — all in under ten minutes (assuming a fast internet connection). Here is that experience in about six minutes:

There are many benefits to schema-less NoSQL datastores, but there are always trade-offs. The primary gift the NoSQL movement has given us is the variety of options we now have for data persistence. With NoSQL we no longer must try to shoehorn everything into a relational model. Now the challenge is in deciding which persistence model fits best with each domain in a system and then combining those models in a cohesive way. The general term to describe this is [Polyglot Persistence][1] and there are many ways to accomplish it. Lets walk through how you can combine a regular SQL model with a key-value NoSQL model using Java, Spring, Hibernate, and PostgreSQL.

Many of the new JVM-based web frameworks are ditching containers and WAR files and instead using a WAR-less / Containerless approach. But that doesn’t mean you have to ditch your favorite Java web framework. A while back I posted about going containerless with Tapestry. Now lets do the same with Spring MVC. You can grab the full source code from GitHub.

First we need a build that defines the dependencies. Here is the build.gradle file for my Gradle build:

Recently I co-presented a webinar about how to integrate Java Spring Apps on Heroku with the Force.com / Salesforce.com REST APIs. Check out the recording:

I’ve also created an in-depth walk through of the code example and step-by-step instructions for setting up and deploying the example Java Spring app on Heroku. Check it out and let me know how it goes.

Last week I hosted a webinar about running Java apps on Heroku that use the Spring Framework and the [Neo4j graph database][1]. Here is the recording of that webinar:

In the webinar I began by deploying a copy of the Spring MVC + Hibernate template app from [heroku.com/java][2] on Heroku. Then I made a few modifications to the app to switch the persistence from Hibernate / JPA to Neo4j. You can get the [full source code on GitHub][3].

Last week I announced the WebJars project that allows you to specify your web libraries (JavaScript, CSS, etc) as dependencies in your Java web applications. With some help from Jeremy Grelle I was able to get a simple WebJars Spring MVC example working.

First you will need to add the WebJars repository to your build. For Maven, just add the following to your “pom.xml” build file:

<repositories>
        <repository>
            <id>webjars</id>
            <url>http://webjars.github.com/m2</url>
        </repository>
    </repositories>

Then add a WebJar dependency, like Twitter Bootstrap:

At SpringOne 2GX I did a presentation about running Spring Roo (really Spring anything) and Grails apps on the cloud with Heroku. A video recording of my session has been posted on InfoQ.

If you want to try out Spring Roo or Grails on Heroku then one way is to deploy a copy of one of the demos I showed. I’ve created a little app that makes that easy. Just go to java.herokuapp.com and select a demo then enter your email address (your Heroku username) and click Go! A copy of the demo will be deployed for you on Heroku and then you will see instructions on how to get started with it. Give it a try and let me know what you think.

In a few weeks I’ll be speaking in Atlanta at DevNexus and at the Atlanta Flex User Group. On March 21, 2011 at DevNexus I have two sessions:

• AS34J - ActionScript for Java Developers
• Rapid Mobile & Tablet App Development with Spring and Flex

On March 22, 2011 at the Atlanta Flex User Group I will be presenting about Flex 4.5 - The Non-Mobile New Features.

I hope to see you at DevNexus and at the Atlanta Flex User Group!