z2-Environment

h1. Hello World Web App Sample

TBC

This sample application shows how to set up the most basic Java Web application in z2. 

Z2 integrates with the Jetty Web container and Web applications on Z2 are really just standard Java EE Web applications. What is unfamiliar for the typical Maven, Gradle, or Ant user is how applications are developed and modularized on Z2. So this sample case is hence more about Web applications as developed on Z2 than it is about Web application development.

Please skip to [[#Step by Step - Or Setting Things Up Yourself|Step by Step - Or Setting Things Up Yourself]] unless you just want to see it running.

This sample is stored in the repository "z2-samples-hello-world-web":https://redmine.z2-environment.net/projects/z2-samples/repository/z2-samples-hello-world-web.

h2. Prerequisites

{{include(Java_Version_Requirements)}}

h2. Setting up the sample

Follow these instructions, if you just want to see it running. Otherwise we recommend skipping this section and rather follow the step by step instructions below.

Here's the really fast version:

{{include(Install_sample_prefix)}}

<pre><code>

git clone -b v2.8 https://www.z2-environment.net/git/z2-samples-hello-world-web

</code></pre>

{{include(Install_sample_postfix)}}

The first time you launch the sample, it will take a while to download all required resources.

h2. Step by Step - Or Setting Things Up Yourself

In this section we will manually create the basic structure of a Z2 module and see how it is discovered by Z2 during development.

We assume that you have prepared some development workspace install and that you installed z2-base.core, the core runtime of z2 in that folder. If you have not done so yet, run

{{include(Install_sample_prefix)}}

h3. Create a Module

Change into install and create a folder z2-samples-hello-world-web and in that folder create the following structure

In this section we will manually create the basic structure of a Z2 module and see how it is discovered by Z2 during development.

We assume that you have prepared some development workspace install and that you installed z2-base.core, the core runtime of z2 in that folder. If you have not done so yet, run

{{include(Install_sample_prefix)}}

h3. Create a Module

Change into install and create a folder z2-samples-hello-world-web and in that folder create the following structure

In this section we will manually create the basic structure of a Z2 module and see how it is discovered by Z2 during development.

We assume that you have prepared some development workspace install and that you installed z2-base.core, the core runtime of z2 in that folder. If you have not done so yet, run

{{include(Install_sample_prefix)}}

h3. Create a Module

Change into install and create a folder z2-samples-hello-world-web and in that folder create the following structure

<pre>

├── java

│   ├── src.api

│   ├── src.impl

│   └── z.properties

└── web

    ├── WebContent

    │   └── WEB-INF

    │       └── web.xml

    └── z.properties

</pre>

where @java/z.properties@:

<pre><code class="java">

com.zfabrik.component.type=com.zfabrik.java

java.privateReferences=\

	com.zfabrik.servletjsp

</code></pre>

and @web/z.properties@:

<pre><code class="java">

com.zfabrik.component.type=com.zfabrik.ee.webapp

webapp.path=/hello-world

webapp.requiredPaths=

webapp.server=environment/webServer

com.zfabrik.systemStates.participation=environment/webWorkerUp

</code></pre>

and @web/WEB-INF/web.xml@:

<pre><code class="xml">

<?xml version="1.0" encoding="UTF-8"?>

<web-app id="z2WebApp" version="3.0"

	xmlns="http://java.sun.com/xml/ns/javaee"

	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">

</web-app>

</code></pre>

*Note:* If you are using the Eclipse IDE and have installed the eclipsoid plugin ([[How_to_install_Eclipsoid]]) you can use the wizard at "File > New > Other > New Java/Web z2-Project". Note however that it may be necessary to adapt the generated files to match the ones above (in particular check for @web.xml@ to refere to servlet api 3.0 at least).

This is the most essential module structure for a Web Application. You will find all Web Application resources directly under the web folder. Java resources however would be put into the java component folder, in src.impl if they are not to be re-used by (or "be visible to") other modules, in src.api, if they are not to be re-used by (and hence "not visible to") other modules.