Another programming blog.
Hello, Recently I got a new job in a very distant city so I’m moving, finding a house and trying bring my family here. So, I can’t continue the project of ‘Developing a Finance Management Website’ for now. Thanks to everyone who took some time to read it.
Enhancing our Entities Let’s talk about Finder. It’s a feature from Ebean that allow us to enhance our entity with methods that will handle querying the database for that specific entity. With Kotlin, we can use it as a companion object to really make our life easier. Let me show you: Now my Script entity will have methods like all(), query(), byId(), update() and many more. Take a look on the someExamples function on the Gist above, pretty easy right? You could even create a ScriptFinder class extending Finder and create your own queries. In my case, I rather just...
UML to Entity Hello everyone and welcome back. On today’s post I’m going to continue the development of a finance management website. For those who are just finding me, this is not your usual tutorial. This is a log of sorts of my activities and thinking while I develop this application. You will find novice to advanced information here and it will come slowly because, most of all, I want to log my thinking and practice writing. Our entities On my last post I guide us on creating a Ktor project. If you wanna have a look, it’s here and...
Creating a Ktor Project.
Part #3 of the series “Developing a Finance Management Website”
by Marcelus Trojahn · Published August 30, 2019 · Last modified September 1, 2019
Classes and thoughts behind them This was originally posted on Medium. Let’s say I’m the neighborhood nerdy guy that occasionally fixes every neighbor’s computers, routers, printers and maybe even create some artwork on Photoshop or whatever. What do I need to know about my money? I need to know who paid me and what was the service I provided. I need to know where I bought some tool and how much it costed me. I need to keep track of Janet that pays me monthly to help her figuring out her own Excel spreadsheet. So, right now, in a very...
Blog / DFMW Series / Tutorial
by Marcelus Trojahn · Published August 30, 2019 · Last modified September 1, 2019
#1 – Intro This was originally posted on Medium. From nothing to something. Hello readers. First of all, let me introduce myself. I’m Marcelus and I’ve been developing small automation solutions to local companies from my city for the past 2 decades. I’m self-taught on everything related to IT and I never stop learning new things. It’s kinda what I do. Ah, even English is self-taught so pardon me already if I make mistakes while I write this. I’m not, by any means, a writer but I always wanted to contribute with my knowledge to other people… And by that...
Hello again. This week I had to study how to implement i18n in a Spring Boot + Thymeleaf CRM application I am developing. Spring Boot really makes it easy to setup but while I was searching about it on the Web I found a lot of misinformation and so I decided to make a post about it. As usual, you can find the complete project on Github: https://github.com/mtrojahn/springboot-thymeleaf-i18n. Let’s start by the pom.xml:
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<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.marcelustrojahn</groupId> <artifactId>springboot-thymeleaf-i18n</artifactId> <version>1.0-SNAPSHOT</version> <packaging>jar</packaging> <name>springboot-thymeleaf-i18n</name> <description>Example on how to implement i18n with Spring Boot and Thymeleaf</description> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> <java.version>1.8</java.version> </properties> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.4.3.RELEASE</version> <relativePath/> <!-- lookup parent from repository --> </parent> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-thymeleaf</artifactId> </dependency> <dependency> <groupId>org.codehaus.groovy</groupId> <artifactId>groovy</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-devtools</artifactId> <optional>true</optional> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> <plugin> <groupId>org.codehaus.gmavenplus</groupId> <artifactId>gmavenplus-plugin</artifactId> <version>1.5</version> <executions> <execution> <goals> <goal>addSources</goal> <goal>addTestSources</goal> <goal>generateStubs</goal> <goal>compile</goal> <goal>testGenerateStubs</goal> <goal>testCompile</goal> <goal>removeStubs</goal> <goal>removeTestStubs</goal> </goals> </execution> </executions> </plugin> </plugins> </build> </project> |
Application.groovy
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package com.marcelustrojahn.boot import org.springframework.boot.SpringApplication import org.springframework.boot.autoconfigure.SpringBootApplication import org.springframework.context.annotation.ComponentScan @SpringBootApplication @ComponentScan(basePackages = ["com.marcelustrojahn.controllers"]) class Application { static void main(String[] args) { SpringApplication.run(Application, args) } } |
As you can see, Application.groovy is pretty much the default for any Spring Boot application. I only changed @ComponentScan to lookup the package that...
This is probably not the best approach and you guys can feel free to correct me in the comments section, but here is a simple tutorial on how I’m getting my fragments loaded via ajax. Same as before, the full project is on my Github: https://github.com/mtrojahn/spring-thymeleaf-fragments-from-ajax Let’s get to it: MyController.groovy
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@Controller class MyController { @GetMapping(['/', '/index.html']) def index(Model model) { 'index' } @GetMapping('/frag1') def frag1(Model model) { model.addAttribute("content", "hello") "fragments/frag1 :: content" } @GetMapping('/frag2') def frag2(Model model) { model.addAttribute("content", "world") "fragments/frag2 :: content" } } |
Very simple controller. Nothing special except for the fact it’s returning Thymeleaf fragmets from /resources/templates/fragments. As you probably noticed, for the sake of this example, each fragment is recieving it’s “content” from the controller. Here’s a fragment: frag1.html
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<th:block th:fragment="content" xmlns="http://www.w3.org/1999/xhtml" xmlns:th="http://www.thymeleaf.org"> <div th:text="${content}"></div> </th:block> |
Now the index.html
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<!DOCTYPE html> <html lang="en" xmlns="http://www.w3.org/1999/xhtml" xmlns:th="http://www.thymeleaf.org"> <head> <meta charset="UTF-8"/> <title>Title</title> <script src="webjars/jquery/3.1.0/jquery.js"></script> </head> <body> <button id="bt1">Load Fragment 1</button> <button id="bt2">Load Fragment 2</button> <div id="content"></div> <script> /*<![CDATA[*/ $("#bt1").on("click", function () { $("#content").load("/frag1"); }); $("#bt2").on("click", function () { $("#content").load("/frag2"); }); /*]]>*/ </script> </body> </html> |
Each button has it’s event and is calling...
It’s been a while! Project for this post: https://github.com/mtrojahn/spring-boot-websocket Recently I stumbled upon the need of using Websockets. I confess I know little about the subject and I hope this little tutorial can help you to get started. I’m making this post just because I tried to help here on StackOverflow and I thought I should just post it here as well. pom.xml
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<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.marcelustrojahn</groupId> <artifactId>spring-boot-websocket-example</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>jar</packaging> <name>spring-boot-websocket-example</name> <description>Simple Websocket Example</description> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.4.0.RELEASE</version> <relativePath/> <!-- lookup parent from repository --> </parent> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> <java.version>1.8</java.version> </properties> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-websocket</artifactId> </dependency> <dependency> <groupId>org.codehaus.groovy</groupId> <artifactId>groovy</artifactId> </dependency> <dependency> <groupId>org.webjars</groupId> <artifactId>sockjs-client</artifactId> <version>1.0.2</version> </dependency> <dependency> <groupId>org.webjars.bower</groupId> <artifactId>stomp-websocket</artifactId> <version>2.3.4</version> </dependency> <dependency> <groupId>org.webjars</groupId> <artifactId>jquery</artifactId> <version>3.1.0</version> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> <plugin> <groupId>org.codehaus.gmavenplus</groupId> <artifactId>gmavenplus-plugin</artifactId> <version>1.5</version> <executions> <execution> <goals> <goal>addSources</goal> <goal>addTestSources</goal> <goal>generateStubs</goal> <goal>compile</goal> <goal>testGenerateStubs</goal> <goal>testCompile</goal> <goal>removeStubs</goal> <goal>removeTestStubs</goal> </goals> </execution> </executions> </plugin> </plugins> </build> </project> |
Application.class (nothing special here)
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package com.marcelustrojahn import org.springframework.boot.SpringApplication import org.springframework.boot.autoconfigure.SpringBootApplication @SpringBootApplication class Application { static void main(String[] args) { SpringApplication.run Application, args } } |
WebSocketConfiguration.class
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package com.marcelustrojahn import org.springframework.context.annotation.Configuration import org.springframework.messaging.simp.config.MessageBrokerRegistry import org.springframework.web.socket.config.annotation.AbstractWebSocketMessageBrokerConfigurer import org.springframework.web.socket.config.annotation.EnableWebSocketMessageBroker import org.springframework.web.socket.config.annotation.StompEndpointRegistry @Configuration @EnableWebSocketMessageBroker class WebSocketConfiguration extends AbstractWebSocketMessageBrokerConfigurer { void configureMessageBroker(MessageBrokerRegistry config) { config.enableSimpleBroker("/topic") config.setApplicationDestinationPrefixes("/app") } @Override void registerStompEndpoints(StompEndpointRegistry stompEndpointRegistry) { stompEndpointRegistry.addEndpoint("/websocket").withSockJS() } } |
PingPongController.class
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package com.marcelustrojahn import org.springframework.beans.factory.annotation.Autowired import org.springframework.messaging.handler.annotation.MessageMapping import org.springframework.messaging.handler.annotation.SendTo import org.springframework.messaging.simp.SimpMessagingTemplate import org.springframework.scheduling.annotation.EnableScheduling import org.springframework.scheduling.annotation.Scheduled import org.springframework.stereotype.Controller @Controller @EnableScheduling class PingPongController { @Autowired SimpMessagingTemplate template @Scheduled(fixedDelay = 20000L) @SendTo("/topic/pingpong") def sendPong() { template.convertAndSend("/topic/pingpong", "pong (periodic)") } @MessageMapping("/ping") @SendTo("/topic/pingpong") def sendPingResponse() { "pong (response)" } } |
This is the main thing. For this example I added a scheduled method that will periodically broadcast a message to all clients and another method that will just...
The complete project can be found here: https://github.com/mtrojahn/spring-boot-groovy-zk As you already know if you read my previous posts, I kinda decided to shift my focus to Groovy and I’m learning as I go. Feel free to correct me any time on the comments if you feel I’m doing something wrong or not optimal. In this post I’ll show how to integrate the ZK Framework on a Spring-Boot project just to output a “Hello World” message coming from an autowired bean just so we can check if everything is correctly wired. As usual, let’s start with the build.gradle file:
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group 'com.mtrojahn' version '1.0-SNAPSHOT' buildscript { repositories { mavenCentral() } dependencies { classpath "org.springframework.boot:spring-boot-gradle-plugin:1.3.0.RELEASE" } } apply plugin: 'groovy' apply plugin: 'spring-boot' repositories { mavenCentral() maven { url "http://mavensync.zkoss.org/maven2" } } sourceCompatibility = 1.8 targetCompatibility = 1.8 configurations { all*.exclude group: 'org.slf4j', module: 'slf4j-jdk14' } dependencies { compile "org.springframework.boot:spring-boot-starter-web" compile "org.zkoss.zk:zkplus:8.0.0" compile "org.zkoss.zk:zkbind:8.0.0" compile "org.zkoss.zk:zkspring-core:3.0" compile 'org.codehaus.groovy:groovy-all' testCompile "junit:junit" } bootRun { addResources = true } |
Ok,...
The complete project can be found here: https://github.com/mtrojahn/spring-boot-groovy-mvc-simple This is yet another very basic example. This time I’ll show how to create get a Web-MVC Spring-Boot project started. You will notice I take the no-XML approach and I’ll try to keep my examples as XML-free as they can be because it’s hard to find fresh documentation about it on the Web. So, let me start with the build.gradle file:
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group 'com.mtrojahn' version '1.0-SNAPSHOT' buildscript { repositories { mavenCentral() } dependencies { classpath "org.springframework.boot:spring-boot-gradle-plugin:1.3.0.RELEASE" } } apply plugin: 'groovy' apply plugin: 'spring-boot' repositories { mavenCentral() } sourceCompatibility = 1.8 targetCompatibility = 1.8 dependencies { compile "org.springframework.boot:spring-boot-starter-web" compile 'org.codehaus.groovy:groovy-all' testCompile "junit:junit" } bootRun { addResources = true } |
As you can see, no big changes from my previous example. Basically all you have to do is change spring-boot-starter to spring-boot-starter-web. Ok, now let’s have a look on the...
The complete code for this project can be found here: https://github.com/mtrojahn/spring-boot-groovy-console-app Last weekend I was playing around with Gradle which I have never used before. The result is this very basic spring-boot project just to illustrate how I did it. Gradle isn’t that difficult but I had a few problems until I learn about the spring-boot-gradle-plugin and such. This is the build.gradle:
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group 'com.mtrojahn' version '1.0-SNAPSHOT' buildscript { repositories { mavenCentral() } dependencies { classpath "org.springframework.boot:spring-boot-gradle-plugin:1.3.0.RELEASE" } } apply plugin: 'groovy' apply plugin: 'spring-boot' repositories { mavenCentral() } sourceCompatibility = 1.8 targetCompatibility = 1.8 dependencies { compile "org.springframework.boot:spring-boot-starter" compile 'org.codehaus.groovy:groovy-all' testCompile "junit:junit" } bootRun { addResources = true } |
As you can see it’s fairly simple and way more organized than Maven in my opinion. The spring-boot-gradle-plugin is the key here. It provides all the version information for the dependencies and also adds a Gradle task...
