spring-boot-vuejs

If you´re a JavaMagazin / blog.codecentric.de / Softwerker reader, consider switching to vue-cli-v2-webpack-v3

A live deployment is available on Heroku: https://spring-boot-vuejs.herokuapp.com

This project is used as example in a variety of articles & as eBook:

blog.codecentric.de/en/2018/04/spring-boot-vuejs | JavaMagazin 8.2018 | entwickler.press shortcuts 229 | softwerker Vol.12

Upgrade procedure

Get newest node & npm:

brew upgrade node
npm install -g npm@latest

Update vue-cli

npm install -g @vue/cli

Update Vue components/plugins (see https://cli.vuejs.org/migrating-from-v3/#upgrade-all-plugins-at-once)

vue upgrade

In Search of a new Web Frontend-Framework after 2 Years of absence...

Well, I’m not a Frontend developer. I’m more like playing around with Spring Boot, Web- & Microservices & Docker, automating things with Ansible and Docker, Scaling things with Spring Cloud, Docker Compose, and Traefik... And the only GUIs I’m building are the "new JS framework in town"-app every two years... :) So the last one was Angular 1 - and it felt, as it was a good choice! I loved the coding experience and after a day of training, I felt able to write awesome Frontends...

But now we’re 2 years later and I heard from afar, that there was a complete rewrite of Angular (2), a new kid in town from Facebook (React) and lots of ES201x stuff and dependency managers like bower and Co. So I’m now in the new 2-year-cycle of trying to cope up again - and so glad I found this article: https://medium.com/reverdev/why-we-moved-from-angular-2-to-vue-js-and-why-we-didnt-choose-react-ef807d9f4163

Key points are:

• Angular 2 isn’t the way to go if you know version 1 (complete re-write, only with Typescript, loss of many of 1’s advantages, Angular 4 is coming)
• React (facebookish problems (licence), need to choose btw. Redux & MObX, harder learning curve, slower coding speed)

And the introduction phrase sounds really great:

Vue (pronounced /vjuː/, like view) is a progressive framework for building user interfaces. Unlike other monolithic frameworks, Vue is designed from the ground up to be incrementally adoptable. The core library is focused on the view layer only and is very easy to pick up and integrate with other libraries or existing projects. On the other hand, Vue is also perfectly capable of powering sophisticated Single-Page Applications when used in combination with modern tooling and supporting libraries.

So I think, it could be a good idea to invest a day or so into Vue.js. Let’s have a look here!

Setup Vue.js & Spring Boot

Prerequisites

MacOSX

brew install node
npm install -g @vue/cli

Linux

sudo apt update
sudo apt install node
npm install -g @vue/cli

Windows

choco install npm
npm install -g @vue/cli

Project setup

spring-boot-vuejs
├─┬ backend     → backend module with Spring Boot code
│ ├── src
│ └── pom.xml
├─┬ frontend    → frontend module with Vue.js code
│ ├── src
│ └── pom.xml
└── pom.xml     → Maven parent pom managing both modules

Backend

Go to https://start.spring.io/ and initialize a Spring Boot app with Web and Actuator. Place the zip’s contents in the backend folder.

Customize pom to copy content from Frontend for serving it later with the embedded Tomcat:

<build>
  <plugins>
    <plugin>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-maven-plugin</artifactId>
    </plugin>
    <plugin>
      <artifactId>maven-resources-plugin</artifactId>
      <executions>
        <execution>
          <id>copy Vue.js frontend content</id>
          <phase>generate-resources</phase>
          <goals>
            <goal>copy-resources</goal>
          </goals>
          <configuration>
            <outputDirectory>src/main/resources/public</outputDirectory>
            <overwrite>true</overwrite>
            <resources>
              <resource>
                <directory>${project.parent.basedir}/frontend/target/dist</directory>
                <includes>
                  <include>static/</include>
                  <include>index.html</include>
                  <include>favicon.ico</include>
                </includes>
              </resource>
            </resources>
          </configuration>
        </execution>
      </executions>
    </plugin>
  </plugins>
</build>

Frontend

Creating our frontend project is done by the slightly changed (we use --no-git here, because our parent project is already a git repository and otherwise vue CLI 3 would initialize an new one):

vue create frontend --no-git

see https://cli.vuejs.org/guide/

This will initialize a project skeleton for Vue.js in /frontend directory - it, therefore, asks some questions in the cli:

Do not choose the default preset with default (babel, eslint), because we need some more plugins for our project here (choose the Plugins with the space bar):

You can now also use the new vue ui command/feature to configure your project:

If you want to learn more about installing Vue.js, head over to the docs: https://vuejs.org/v2/guide/installation.html

Use frontend-maven-plugin to handle NPM, Node, Bower, Grunt, Gulp, Webpack and so on :)

If you’re a backend dev like me, this Maven plugin here https://github.com/eirslett/frontend-maven-plugin is a great help for you - because, if you know Maven, that’s everything you need! Just add this plugin to the frontend’s pom.xml:

<build>
    <plugins>
        <plugin>
            <groupId>com.github.eirslett</groupId>
            <artifactId>frontend-maven-plugin</artifactId>
            <version>${frontend-maven-plugin.version}</version>
            <executions>
                <!-- Install our node and npm version to run npm/node scripts-->
                <execution>
                    <id>install node and npm</id>
                    <goals>
                        <goal>install-node-and-npm</goal>
                    </goals>
                    <configuration>
                        <nodeVersion>v10.10.0</nodeVersion>
                    </configuration>
                </execution>
                <!-- Install all project dependencies -->
                <execution>
                    <id>npm install</id>
                    <goals>
                        <goal>npm</goal>
                    </goals>
                    <!-- optional: default phase is "generate-resources" -->
                    <phase>generate-resources</phase>
                    <!-- Optional configuration which provides for running any npm command -->
                    <configuration>
                        <arguments>install</arguments>
                    </configuration>
                </execution>
                <!-- Build and minify static files -->
                <execution>
                    <id>npm run build</id>
                    <goals>
                        <goal>npm</goal>
                    </goals>
                    <configuration>
                        <arguments>run build</arguments>
        </configuration>
                </execution>
            </executions>
        </plugin>
    </plugins>
</build>

Tell Webpack to output the dist/ contents to target/

Commonly, node projects will create a dist/ directory for builds which contains the minified source code of the web app - but we want it all in /target. Therefore we need to create the optional vue.config.js and configure the outputDir and assetsDir correctly:

module.exports = {
  ...
  // Change build paths to make them Maven compatible
  // see https://cli.vuejs.org/config/
  outputDir;: 'target/dist',
  assetsDir;: 'static';
}

First App run

Inside the root directory, do a:

mvn clean install

Run our complete Spring Boot App:

mvn --projects backend spring-boot:run

Now go to http://localhost:8098/ and have a look at your first Vue.js Spring Boot App.

Faster feedback with webpack-dev-server

The webpack-dev-server, which will update and build every change through all the parts of the JavaScript build-chain, is pre-configured in Vue.js out-of-the-box! So the only thing needed to get fast feedback development-cycle is to cd into frontend and run:

npm run serve

That’s it!

Browser developer tools extension

Install vue-devtools Browser extension https://github.com/vuejs/vue-devtools and get better feedback, e.g. in Chrome:

IntelliJ integration

There's a blog post: https://blog.jetbrains.com/webstorm/2018/01/working-with-vue-js-in-webstorm/

Especially the New... Vue Component looks quite cool :)

HTTP calls from Vue.js to (Spring Boot) REST backend

Prior to Vue 2.0, there was a build in solution (vue-resource). But from 2.0 on, 3rd party libraries are necessary. One of them is Axios - also see blog post https://alligator.io/vuejs/rest-api-axios/

npm install axios --save

Calling a REST service with Axios is simple. Go into the script area of your component, e.g. Hello.vue and add:

import axios from 'axios'

data ();{
  return {
    response: [],
    errors: []
  }
},

callRestService ();{
  axios.get(`api/hello`)
    .then(response => {
      // JSON responses are automatically parsed.
      this.response = response.data
    })
    .catch(e => {
      this.errors.push(e)
    })
}
}

In your template area you can now request a service call via calling callRestService() method and access response data:

<button class=”Search__button” @click="callRestService()">CALL Spring Boot REST backend service</button>

<h3>{{ response }}</h3>

The problem with SOP

Single-Origin Policy (SOP) could be a problem if we want to develop our app. Because the webpack-dev-server runs on http://localhost:8080 and our Spring Boot REST backend on http://localhost:8098.

We need to use Cross-Origin Resource Sharing Protocol