Create and Run Your First ZK Application with Spring Boot

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DocumentationZK Installation GuideQuick StartCreate and Run Your First ZK Application with Spring Boot
Create and Run Your First ZK Application with Spring Boot

Starting from Scratch

To get started follow these simple steps or clone/run one of the available demos.

1. Download/unzip a standard Spring Initializr project

(no addons needed, tested with version 2.0.4.RELEASE)

2. Add ZK's maven-repository and the zkspringboot-starter dependency

In pom.xml add: replace ${zkspringboot.version} with the latest version

			<id>ZK CE</id>
			<name>ZK CE Repository</name>

3. Create a simple zul file

e.g: src/main/resources/web/hello.zul

    <window title="Hello ZK - Spring Boot!" border="normal">
        You are using ZK version <label value="${session.webApp.version}"/>

4. Define a homepage

in src/main/resources/


5. Run the application

execute the command (on windows omit the './' prefix)

./mvnw spring-boot:run

6. Open the URL


Now you have a ZK application running on Spring boot. For further details and differences to a normal ZK web application read the details below.

The ZK - Spring Boot Demos

The demo projects are located on github/zkoss/zkspringboot. To run them all you need is a command line interface (and optional: git).

These examples are derived from the Spring Boot - Getting Started Guide replacing the springboot-starter-web dependency by zkspringboot-starter to enable convenient auto-configuration for the most common usage scenarios while allowing customization where needed.

Differences to a "normal" ZK Web Application


As Spring Boot prefers Java- over XML-configuration and doesn't require a classical src/main/webapp-folder (and no WEB-INF/). Hence the ZK configuration files are moved to a different files/folders:

zk.xml and were moved to a classpath location:

src/main/webapp/WEB-INF/zk.xml -> src/main/resources/metainfo/zk/zk.xml
src/main/webapp/WEB-INF/ -> src/main/resources/metainfo/

web.xml configuration such as servlets/filters are configured the "Spring Boot Way" using java configuration

src/main/webapp/WEB-INF/web.xml -> auto configuration is provided by the zkspringboot-starter dependency (configurable via

After adding the zkspringboot-starter dependency the @SpringBootApplicatio-annotation is sufficient to make initialize ZK.

public class Application  {
	public static void main(String[] args) {, args);

For a single-page-application all you need is to specify a view name as the zk.homepage parameter in the (or specify a richlet).

Multiple zul-files as entry points for your application are defined using Spring-MVC's @GetMapping annotatios.


Application structure

In the zkspringboot-demo-jar example the zul files are located below the class web resource folder src/main/resources/web/zul/

You can configure any folder below src/main/resources/web using the zk.zul-view-resolver-prefix-property in The extension .zul is added automatically by the default value of zk.zul-view-resolver-suffix.

By default this view resolver is enabled, and can be disabled via zk.zul-view-resolver-enabled (e.g. if no zul files are used (just richlets, or jsp's embedding zul files) or a custom implementation is preferred).

Inside the Zk application zul files (to be included) can be referenced like this:

    <include src="~./zul/mvvm-page1.zul"/>
    <apply templateURI="~./zul/mvvm-page1.zul"/>

General resource folders are:

Spring Boot resources are referenced by urls starting with '/' ZK resources (including zul files) are prefixed with '~./'


    <image src="/img/zklogo1.png"/>      <!-- src/main/resources/static/img/zklogo1.png -->
    <image src="~./img/zklogo1.png"/>    <!-- src/main/resources/web/img/zklogo3.png -->

Examples how to access resources from either resource folder are:

Zats Testing

Since Zats is running its own embedded jetty, it can't use the same application startup mechanism as plain spring boot. In order to allow Zats tests, the Application configuration must be loaded from a separate web.xml (note it is in src/test/webapp so it doesn't affect the production deployment).

As of now you can specify your test context configuration class (e.g. zk.springboot.Application) as a context parameter inside web.xml. The customized ContextLoaderListener ( reads this parameter and initializes the application context accordingly.

E.g. the DemoPageTest-case refers to this web.xml to initialize the spring boot application inside Zats' embedded Jetty.

As usual, alternative test-configuration is possible if needed.

(Feedback regarding a cleaner startup of a Spring Boot project in an alternative embedded container is welcome, to avoid extending/overriding Framework classes.)

Download/Clone the example project

With the git command line installed all you need is to clone the example repository (Alternatively download a zip-package):

   git clone
   cd zkspringboot/zkspringboot-demos

In order to get started immediately the project includes the gradle-wrapper and maven-wrapper.

During the first execution gradle/maven will download itself and all the required project dependencies automatically. This will initially take quite a few minutes while showing the overall progress. Subsequent executions will be faster as gradle/maven will cache downloaded resources. For additional information on gradle/maven please refer to their official documentation.

Build / Run the Project

Please follow the instructions in the

Import the project into your IDE

The project itself designed to work from command line and independent of any IDE. Since it's both a gradle or maven project you can import it into your favorite IDE using the standard plugins provided by the IDE.

TIP: The main class org.zkoss.zkspringboot.demo.DemoApplication can be executed directly in your IDE for development and debugging.

Useful DevelopmentConfig can be enabled by activating the dev-profile as a VM argument in your run configuration.

This will disable resource caches allowing to replace zul/css/js/image files without restarting the application.

Last Update : 2022/01/19

Copyright © Potix Corporation. This article is licensed under GNU Free Documentation License.