So, you need to parse HTML in your Java application. Perhaps you are extracting data from a website that doesn’t have an API, or allowing users to put arbitrary HTML into your app and you need to check that they haven’t tried to do anything nasty?
Have you tried using regular expressions? It won’t end well. The author of that now-infamous text managed to recover from their distress enough to suggest using an XML parser (before, presumably, collapsing into the void). The problem with this is that an awful lot of the HTML in the world is not valid XML. People open tags without closing them, they nest tags wrongly, and generally commit all kinds of XML faux pas. Some non-XML constructs are perfectly valid HTML and admirably, browsers just cope with it.
To adopt the flexible and stylish attitude of web browsers, you really need a dedicated …
Here I’ll show how you can use Shadow CLJS, the Twilio CLI and Serverless Toolkit to create a Twilio Function in ClojureScript. If you want to jump straight to the final code, you can find the project on GitHub.
- Node.js 8.10 or newer
- Java 8 or higher (we won’t use this directly, but the ClojureScript compiler is a Java application)
- The Twilio CLI
Create a new Shadow CLJS project using
npx which is …
JavaFX is a Java toolkit for making GUI applications which run on Windows, MacOS or Linux and mobile. It is the successor to the old Swing and the older AWT toolkits.
Since the release of Java 11 in 2018 JavaFX has been part of the OpenJDK project, so it is open-source and is developed by many people from many different companies. If you are interested in creating a desktop application today then I would recommend starting with JavaFX and not using Swing or AWT, but it can be hard to know how to get started.
This post will walk you through creating a JavaFX desktop application from scratch - the application will use JavaFX’s
controls module to draw a label with some text, then we’ll move on to creating an interactive app that can send SMS messages.
What do I need in order to make a JavaFX Application?
As a programmer you might have to deal with questions like these:
What's bigger, 243 or 7 trillion?
How many items can we store if our database uses a 32-bit identifier?
Calculations involving powers of two come up often in programming, and it's completely possible to work these out in your head faster than opening your calculator app, using this one (weird?) trick.
There are three things to remember:
- First, 2(a+b) = 2a × 2b
- Second, 210 is 1024, which is really close to 1000.
- Third, you need to know the powers of 2 up to 210
These facts are the basis for the rule:
Add three zeros for each ten in the power, then multiply by whatever is left.
Twilio's CEO Jeff Lawson recently wrote about the history of robocalls and what we're doing to eliminate them.
In order to create this project you’ll need
Add the Nomorobo Add-on to your Twilio Account
Head to the Twilio Console and install the Nomorobo add-on. Look for the yellow logo and click through to "Install".
Leave the name as
nomorobo_spamscore and "Save" the Add-On.
Setting Up your Java Project
Create a new Maven project with the java8-quickstart-archetype:
mvn archetype:generate \ -DarchetypeGroupId=pl.org.miki \ -DarchetypeArtifactId=java8-quickstart-archetype \ -DarchetypeVersion=1.0.0 \ -DtestLibrary=none
This command will prompt for a
artifactId. If …
After booking some train journeys with Deutsche Bahn (the German rail network) for my summer vacation this year, I found I needed to call their reservations desk to change something important about my tickets. Unfortunately the number they provide is a specially-priced Premium Rate number in Germany, and international calls to these are blocked from my phone. Twilio’s Programmable Voice products are perfect for solving this kind of problem. Read on to find out how I did it and how you could do the same.
Step 1: Getting A Local Number
The first thing to do is to get a number which you can call. Twilio’s phone numbers console allows us to buy phone numbers in over a hundred countries so once you have signed up for an account click the “+” button to buy a new number that’s local to you:
Step 2: Forwarding Incoming Calls
After buying a …
The Streams API was added in 2014 with the release of Java 8 so you’ve almost certainly got it available today. It is used to pass a series of objects through a chain of operations, so we can program in a more functional style than plain iteration allows. Still, when working with collections many developers still reach for the classic
In this post, I’ll introduce the terms used when talking about Streams, show some examples of each term and how they can be used together to create compact and descriptive code. Then I’ll show a real-world example of Streams code I wrote recently to pick winners in a raffle.
What’s a Stream?
A Stream is a (possibly never-ending) series of Objects. A Stream starts from a Source. The objects in a Stream flow through Intermediate Operations, each of which results in another stream, and are gathered …
When things go wrong in a running Java application, often the first sign you will have is lines printed to the screen that look like this:
Exception in thread "main" java.lang.RuntimeException: Something has gone wrong, aborting! at com.myproject.module.MyProject.badMethod(MyProject.java:22) at com.myproject.module.MyProject.oneMoreMethod(MyProject.java:18) at com.myproject.module.MyProject.anotherMethod(MyProject.java:14) at com.myproject.module.MyProject.someMethod(MyProject.java:10) at com.myproject.module.MyProject.main(MyProject.java:6)
This is a Stacktrace, and in this post I'll explain what they are, how they are made and how to read …
Twilio’s APIs enable communication in a whole host of ways: by phone, WhatsApp, Facebook, SMS and more. Usually when events such as incoming messages or calls happen Twilio will make an HTTP request to a server the user provides to discover what it should do - these are called webhooks. HTTP servers can be written with any technology to respond to these webhooks, and for Java developers the most popular framework is Spring Boot.
In this post we’ll create a Spring Boot app which can respond to incoming phone calls by playing callers a short message followed by the marvellous Rogers and Hammerstein song “It Might As Well Be Spring”.
Creating a Spring Boot App
AI services like Computer Vision (CV) are getting easier and easier to play with, and we can have some fun by making them available to use from our cellphones. In this post, we will use Java to connect the Twilio API for WhatsApp with Azure’s CV APIs to create a bot that can describe photos. It would be neat to use this for generating alt-text to help make your images more accessible online, for example.
We will need the following to get started with this post
- Java 8 or higher
- A Twilio Account
- An Azure account and Cognitive Services subscription key
Overview of our app
How it works
When Twilio receives a WhatsApp message it will send an HTTP request to a URL we provide.
Our mission is to create an app in Java which can handle those requests. The app will take the URL of any …