Implementing a Web Chat With AI in Java

Creating a New Project

Start by generating a new Maven project:

  1. Go to https://start.vaadin.com.
  2. Delete all the default views (Dashboard and Master-Detail).
  3. Add a new view by clicking on the plus icon and select Empty.
  4. Change the name to Chat and the route to chat.
  5. Optional: Tweak the theme using the options on the right side of the page.
  6. Click Download app and set a Project NameJava Group ID, and Vaadin Version (this article uses 14 LTS).
  7. Click Download, unzip the generated file, and import the Maven project into your favorite IDE (see instructions for IntelliJ IDEAEclipse, and NetBeans).
  8. Remove the backend  subpackage and its contents.

#java #web development #machine learning #chatbot #chat #vaadin #artificial inteeligence

What is GEEK

Buddha Community

Implementing a Web Chat With AI in Java
Tyrique  Littel

Tyrique Littel

1600135200

How to Install OpenJDK 11 on CentOS 8

What is OpenJDK?

OpenJDk or Open Java Development Kit is a free, open-source framework of the Java Platform, Standard Edition (or Java SE). It contains the virtual machine, the Java Class Library, and the Java compiler. The difference between the Oracle OpenJDK and Oracle JDK is that OpenJDK is a source code reference point for the open-source model. Simultaneously, the Oracle JDK is a continuation or advanced model of the OpenJDK, which is not open source and requires a license to use.

In this article, we will be installing OpenJDK on Centos 8.

#tutorials #alternatives #centos #centos 8 #configuration #dnf #frameworks #java #java development kit #java ee #java environment variables #java framework #java jdk #java jre #java platform #java sdk #java se #jdk #jre #open java development kit #open source #openjdk #openjdk 11 #openjdk 8 #openjdk runtime environment

Zachary Palmer

Zachary Palmer

1555901576

CSS Flexbox Tutorial | Build a Chat Application

Creating the conversation sidebar and main chat section

In this article we are going to focus on building a basic sidebar, and the main chat window inside our chat shell. See below.

Chat shell with a fixed width sidebar and expanded chat window

This is the second article in this series. You can check out the previous article for setting up the shell OR you can just check out the chat-shell branch from the following repository.

https://github.com/lyraddigital/flexbox-chat-app.git

Open up the chat.html file. You should have the following HTML.

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8" />
    <title>Chat App</title>
    <link rel="stylesheet" type="text/css" media="screen" href="css/chat.css" />
</head>
<body>
    <div id="chat-container">
    </div>
</body>
</html>

Now inside of the chat-container div add the following HTML.

<div id="side-bar">
</div>
<div id="chat-window">
</div>

Now let’s also add the following CSS under the #chat-container selector in the chat.css file.

#side-bar {
    background: #0048AA;
    border-radius: 10px 0 0 10px;
}
#chat-window {
    background: #999;
    border-radius: 0 10px 10px 0;
}

Now reload the page. You should see the following:-

So what happened? Where is our sidebar and where is our chat window? I expected to see a blue side bar and a grey chat window, but it’s no where to be found. Well it’s all good. This is because we have no content inside of either element, so it can be 0 pixels wide.

Sizing Flex Items

So now that we know that our items are 0 pixels wide, let’s attempt to size them. We’ll attempt to try this first using explicit widths.

Add the following width property to the #side-bar rule, then reload the page.

width: 275px;

Hmm. Same result. It’s still a blank shell. Oh wait I have to make sure the height is 100% too. So we better do that too. Once again add the following property to the #side-bar rule, then reload the page.

height: 100%;

So now we have our sidebar that has grown to be exactly 275 pixels wide, and is 100% high. So that’s it. We’re done right? Wrong. Let me ask you a question. How big is the chat window? Let’s test that by adding some text to it. Try this yourself just add some text. You should see something similar to this.

So as you can see the chat window is only as big as the text that’s inside of it, and it is not next to the side bar. And this makes sense because up until now the chat shell is not a flex container, and just a regular block level element.

So let’s make our chat shell a flex container. Set the following display property for the #chat-window selector. Then reload the page.

display: flex;

So as you can see by the above illustration, we can see it’s now next to the side bar, and not below it. But as you can see currently it’s only as wide as the text that’s inside of it.

But we want it to take up the remaining space of the chat shell. Well we know how to do this, as we did it in the previous article. Set the flex-grow property to 1 on the #chat-window selector. Basically copy and paste the property below and reload the page.

flex-grow: 1;

So now we have the chat window taking up the remaining space of the chat shell. Next, let’s remove the background property, and also remove all text inside the chat-window div if any still exists. You should now see the result below.

But are we done? Technically yes, but before we move on, let’s improve things a little bit.

Understanding the default alignment

If you remember, before we had defined our chat shell to be a flex container, we had to make sure we set the height of the side bar to be 100%. Otherwise it was 0 pixels high, and as a result nothing was displayed. With that said, try removing the height property from the #side-bar selector and see what happens when you reload the page. Yes that’s right, it still works. The height of the sidebar is still 100% high.

So what happened here? Why do we no longer have to worry about setting the height to 100%? Well this is one of the cool things Flexbox gives you for free. By default every flex item will stretch vertically to fill in the entire height of the flex container. We can in fact change this behaviour, and we will see how this is done in a future article.

Setting the size of the side bar properly

So another feature of Flexbox is being able to set the size of a flex item by using the flex-basis property. The flex-basis property allows you to specify an initial size of a flex item, before any growing or shrinking takes place. We’ll understand more about this in an upcoming article.

For now I just want you to understand one important thing. And that is using width to specify the size of the sidebar is not a good idea. Let’s see why.

Say that potentially, if the screen is mobile we want the side bar to now appear across the top of the chat shell, acting like a top bar instead. We can do this by changing the direction flex items can flex inside a flex container. For example, add the following CSS to the #chat-container selector. Then reload the page.

flex-direction: column;

So as you can see we are back to a blank shell. So firstly let’s understand what we actually did here. By setting the flex-direction property to column, we changed the direction of how the flex items flex. By default flex items will flex from left to right. However when we set flex-direction to column, it changes this behaviour forcing flex items to flex from top to bottom instead. On top of this, when the direction of flex changes, the sizing and alignment of flex items changes as well.

When flexing from left to right, we get a height of 100% for free as already mentioned, and then we made sure the side bar was set to be 275 pixels wide, by setting the width property.

However now that we a flexing from top to bottom, the width of the flex item by default would be 100% wide, and you would need to specify the height instead. So try this. Add the following property to the #side-bar selector to set the height of the side bar. Then reload the page.

height: 275px;

Now we are seeing the side bar again, as we gave it a fixed height too. But we still have that fixed width. That’s not what we wanted. We want the side bar (ie our new top bar) here to now be 100% wide. Comment out the width for a moment and reload the page again.

So now we were able to move our side bar so it appears on top instead, acting like a top bar. Which as previously mentioned might be suited for mobile device widths. But to do this we had to swap the value of width to be the value of height. Wouldn’t it be great if this size was preserved regardless of which direction our items are flexing.

Try this, remove all widths and height properties from the #side-bar selector and write the following instead. Then reload the page.

flex-basis: 275px;

As you can see we get the same result. Now remove the flex-direction property from the #chat-container selector. Then once again reload the page.

Once again we are back to our final output. But now we also have the flexibility to easily change the side bar to be a top bar if we need to, by just changing the direction items can flow. Regardless of the direction of flex, the size of our side bar / top bar is preserved.

Conclusion

Ok so once again we didn’t build much, but we did cover a lot of concepts about Flexbox around sizing. 

#css #programming #webdev 

Joseph  Murray

Joseph Murray

1623302550

Top 5 Java Web Application Technologies You Should Master in 2021

Web Development in Java

Java is a commonly used language for web development, especially on the server-side. Java web applications are distributed applications that run on the internet. Web development with Java allows us to create dynamic web pages where users can interact with the interface.

There are various ways through which you can create dynamic web pages in Java. The Java EE (Enterprise Edition) platform provides various Java technologies for web development to developers. Services like distributed computing, web services, etc. are provided by Java EE. Applications can be developed in Java without using any additional scripting language. Let us see how web applications are made via Java.

**Java Web Application **

Java Web Application Technologies

#software development #java #java web applications #web applications #java web application technologies #top 5 java web application technologies you should master

Roberta  Ward

Roberta Ward

1595344320

Wondering how to upgrade your skills in the pandemic? Here's a simple way you can do it.

Corona Virus Pandemic has brought the world to a standstill.

Countries are on a major lockdown. Schools, colleges, theatres, gym, clubs, and all other public places are shut down, the country’s economy is suffering, human health is on stake, people are losing their jobs and nobody knows how worse it can get.

Since most of the places are on lockdown, and you are working from home or have enough time to nourish your skills, then you should use this time wisely! We always complain that we want some ‘time’ to learn and upgrade our knowledge but don’t get it due to our ‘busy schedules’. So, now is the time to make a ‘list of skills’ and learn and upgrade your skills at home!

And for the technology-loving people like us, Knoldus Techhub has already helped us a lot in doing it in a short span of time!

If you are still not aware of it, don’t worry as Georgia Byng has well said,

“No time is better than the present”

– Georgia Byng, a British children’s writer, illustrator, actress and film producer.

No matter if you are a developer (be it front-end or back-end) or a data scientisttester, or a DevOps person, or, a learner who has a keen interest in technology, Knoldus Techhub has brought it all for you under one common roof.

From technologies like Scala, spark, elastic-search to angular, go, machine learning, it has a total of 20 technologies with some recently added ones i.e. DAML, test automation, snowflake, and ionic.

How to upgrade your skills?

Every technology in Tech-hub has n number of templates. Once you click on any specific technology you’ll be able to see all the templates of that technology. Since these templates are downloadable, you need to provide your email to get the template downloadable link in your mail.

These templates helps you learn the practical implementation of a topic with so much of ease. Using these templates you can learn and kick-start your development in no time.

Apart from your learning, there are some out of the box templates, that can help provide the solution to your business problem that has all the basic dependencies/ implementations already plugged in. Tech hub names these templates as xlr8rs (pronounced as accelerators).

xlr8rs make your development real fast by just adding your core business logic to the template.

If you are looking for a template that’s not available, you can also request a template may be for learning or requesting for a solution to your business problem and tech-hub will connect with you to provide you the solution. Isn’t this helpful 🙂

Confused with which technology to start with?

To keep you updated, the Knoldus tech hub provides you with the information on the most trending technology and the most downloaded templates at present. This you’ll be informed and learn the one that’s most trending.

Since we believe:

“There’s always a scope of improvement“

If you still feel like it isn’t helping you in learning and development, you can provide your feedback in the feedback section in the bottom right corner of the website.

#ai #akka #akka-http #akka-streams #amazon ec2 #angular 6 #angular 9 #angular material #apache flink #apache kafka #apache spark #api testing #artificial intelligence #aws #aws services #big data and fast data #blockchain #css #daml #devops #elasticsearch #flink #functional programming #future #grpc #html #hybrid application development #ionic framework #java #java11 #kubernetes #lagom #microservices #ml # ai and data engineering #mlflow #mlops #mobile development #mongodb #non-blocking #nosql #play #play 2.4.x #play framework #python #react #reactive application #reactive architecture #reactive programming #rust #scala #scalatest #slick #software #spark #spring boot #sql #streaming #tech blogs #testing #user interface (ui) #web #web application #web designing #angular #coronavirus #daml #development #devops #elasticsearch #golang #ionic #java #kafka #knoldus #lagom #learn #machine learning #ml #pandemic #play framework #scala #skills #snowflake #spark streaming #techhub #technology #test automation #time management #upgrade

Samanta  Moore

Samanta Moore

1620458875

Going Beyond Java 8: Local Variable Type Inference (var) - DZone Java

According to some surveys, such as JetBrains’s great survey, Java 8 is currently the most used version of Java, despite being a 2014 release.

What you are reading is one in a series of articles titled ‘Going beyond Java 8,’ inspired by the contents of my book, Java for Aliens. These articles will guide you step-by-step through the most important features introduced to the language, starting from version 9. The aim is to make you aware of how important it is to move forward from Java 8, explaining the enormous advantages that the latest versions of the language offer.

In this article, we will talk about the most important new feature introduced with Java 10. Officially called local variable type inference, this feature is better known as the **introduction of the word **var. Despite the complicated name, it is actually quite a simple feature to use. However, some observations need to be made before we can see the impact that the introduction of the word var has on other pre-existing characteristics.

#java #java 11 #java 10 #java 12 #var #java 14 #java 13 #java 15 #verbosity