Reading and Writing from Excel in Spring Batch

Rik Scarborough Articles, Development Technologies & Tools, Java, Spring, Spring Batch, Tutorial 4 Comments

We have discussed many different ways to read and write data in Spring Batch. The framework comes with quite an assortment of Readers and Writers that can be used directly or reused in some manner. Most of the time, the requirements consist of reading the data from some type of text file or database.

So what happens when the business we are supporting asks for something out of the ordinary, such as reading an Excel file and outputting the data to another Excel file? Typically the off-the-cuff response would be, โ€œcan you convert it to a CSV or other delimited text file?โ€ Or โ€œYou know, Excel will read a CSV file just fine.โ€ Sometimes that works, and sometimes the business requirements do not allow that type of flexibility.

Consider this scenario; in these days of Cloud and other online computing, the input file is likely created by a server that the company has no direct access to as far as programming. The file it creates is in one format, Excel. The output of your process has to go before several executives or other business clients and needs to be formatted in a professional looking manner. Adding a manual process to import a CSV and format it diminishes the value of using Spring Batch.

For the sake of the honor of the coding profession, you agree to the requirement to read and write from an Excel file directly. Now, how do you do that?…

Getting Started with Xamarin Forms and Prism

Ryan Nguyen .NET, Articles, Development Technologies & Tools, Mobile, Xamarin 3 Comments

In this blog, Iโ€™ll show you how easy it is to create an Android and iOS application using Xamarin Forms while utilizing Prism.

What are Xamarin Forms?
Xamarin Forms is a platform that allows developers to create native Android, iOS, and Windows applications while using the beloved C# programming language.ย 

An attractive feature of Xamarin Forms is that it uses a shared C# codebase to create a native user interface specific to their platform. Out of the box, Xamarin provides large collections of controls to get started.ย It also has the ability to access native platform features, such as camera access, GPS, text to speech, etc, by using theย Dependency Service.

What is Prism?
According to the Prism website, Prism is defined as โ€œa framework for building loosely coupled, maintainable, and testable XAML applications in WPF, Windows 10 UWP, and Xamarin Forms. Prism provides an implementation of a collection of design patterns that are helpful in writing well-structured and maintainable XAML applications, including MVVM, dependency injection, commands, EventAggregator, and others.”ย In other words, Prism helps users to write better code….ย 

Rethinking REST Practices: An Introduction to GraphQL with AWS AppSync

Mat Warger API Development, Articles, AWS, Cloud, Development Technologies & Tools, GraphQL, JavaScript, Programming, REST Leave a Comment

The basic premise of data transfer and involves requesting and receiving lists. This is simplistic, but it gets to the root of why weโ€™ve developed the technologies and best practices to pass data using web services. RESTful APIs have grown to serve the needs of numerous individuals, startups, and enterprise companies across the world. They are useful, productive, and the concepts surrounding them are relatively standardized. If you donโ€™t know how to create one, you can quickly find information building a great API that can grow to fit your needs. Thatโ€™s when things get complicatedโ€ฆ

If you start digging into REST, youโ€™ll realize thereโ€™s quite a bit more to throwing lists. There are common threads that many people encounter when developing an API, and you begin to encounter many of the same questions so many others have before, such as: How strictly should you adhere to the principles of REST? How should you handle versioning? Should you bother? How do you want to structure your objects? Are users able to easily figure out what API endpoints are available and how they should be used?

There are many ways approach these. It boils down to communicating the structures that a given endpoint will return or accept. The cascade of questions that results from the choices made here will ripple through from the back-end to the client. The secondary issue is that these questions and choices are not at all uncommon. There are answers to these that follow Best Practices. But there is still plenty of ambiguity involved when attempting to build a flexible API that works well. These are the Commonly Tolerated Situations.

If you hadnโ€™t already guessed, there is a solution that frees us from the dogma of REST and allows us to solve all these issues in a declarative, powerful, and fun way. That solution is GraphQL. In this blog, Iโ€™ll provide an introduction to the GraphQL specification with code examples…

What’s New in JUnit 5.2

Billy Korando Articles, Development Technologies & Tools, Effective Automated Testing With Spring Series, Java, Testing Leave a Comment

The JUnit team continues to make great progress in adding new features and enhancements to the JUnit 5 framework. We already have a second significant feature update after just seven months from the initial release of JUnit 5.

In this article, we look at some of the key features and enhancements added in JUnit 5.2 which was released on April 29th. We’ll focus on build tool enhancements that help in the adoption/migration to JUnit 5 for existing test suites and resolve annoyances, as well as what new changes further improve parameterized tests.

AWS Lambda with Spring Boot

Greg Emerick Articles, AWS, Cloud, Development Technologies & Tools, Java, Spring, Spring Boot 12 Comments

The typical deployment scenario for a Spring Boot application in AWS involves running the Java application on an EC2 instance 24 hours a day. Of course, the application could be deployed in AWS ECS as a Docker container, but it still runs continuously on an EC2 instance. In each case, the EC2 instances need to be monitored and you pay for compute capacity used by that EC2 instance.

AWS Lambda provides low cost compute with zero maintenance. Lambda runs your code on demand, without provisioned and managed servers. Lambda automatically runs and scales your code. You are charged for every 100ms your code executes and the number of times your code is triggered. If the code isnโ€™t running, you pay nothing.

Lambda has clear cost and maintenance benefits. But what does it take to run the standard Spring Boot application as a Lambda? How does it work? What are the drawbacks? These are the questions that will be answered in this blog through a tangible example…