guide client layer

Table of Contents

• Client Layer
  • JavaScript for Java Developers

Client Layer

There are various technical approaches to building GUI clients. The devonfw proposes rich clients that connect to the server via data-oriented services (e.g. using REST with JSON). In general, we have to distinguish among the following types of clients:

• web clients

• native desktop clients

• (native) mobile clients

Our main focus is on web-clients. In our sample application my-thai-star we offer a responsive web-client based on Angular following devon4ng that integrates seamlessly with the back ends of my-thai-star available for Java using devon4j as well as .NET/C# using devon4net. For building angular clients read the separate devon4ng guide.

JavaScript for Java Developers

In order to get started with client development as a Java developer we give you some hints to get started. Also if you are an experienced JavaScript developer and want to learn Java this can be helpful. First, you need to understand that the JavaScript ecosystem is as large as the Java ecosystem and developing a modern web client requires a lot of knowledge. The following table helps you as experienced developer to get an overview of the tools, configuration-files, and other related aspects from the new world to learn. Also it helps you to map concepts between the ecosystems. Please note that we list the tools recommended by devonfw here (and we know that there are alternatives not listed here such as gradle, grunt, bower, etc.).

Table 1. Aspects in JavaScript and Java ecosystem

Topic	Aspect	JavaScript	Java
Programming	Language	TypeScript (extends JavaScript)	Java
Runtime	VM	nodejs (or web-browser)	jvm
Build- & Dependency-Management	Tool	npm or yarn	maven
	Config	package.json	pom.xml
	Repository	npm repo	maven central (repo search)
	Build cmd	ng build or npm run build (goals are not standardized in npm)	mvn install (see lifecycle)
	Test cmd	ng test	mvn test
Testing	Test-Tool	jasmine	junit
	Test-Runner	karma	junit / surefire
	E2E Testing	Protractor	Selenium
Code Analysis	Code Coverage	ng test --no-watch --code-coverage	JaCoCo
Development	IDE	MS VS Code or IntelliJ	Eclipse or IntelliJ
	Framework	Angular (etc.)	Spring or Quarkus