Angular 8 is here! What’s new?

I’ve been using Angular for many years now, started with AngularJS. I simply love it. Angular is an excellent framework for building web applications.

Now Angular has been released in version 8.

This is a new major release spanning the entire platform, including the framework, Angular Material, and the CLI with synchronized major versions.

How to update to version 8

Visit for detailed information and guidance. For most developers, one command should take care of this update:

ng update @angular/cli @angular/core

If you are also using Angular Material

ng update @angular/material

Top 8 Features of Angular 8

* Differential Loading
* Builders API
* Support for $location
* Web Workers
* Router Backwards Compatibility
* Dynamic imports for lazy routes
* Bazel Support

* Ivy Rendering Engine (preview)


Angular 8 now depends on TypeScript 3.4. Check out the release notes to know what has changed.

How To Read HTTP Request Header in Spring MVC

This short tutorial is about how to read the HTTP request header in the spring framework.

While refactoring a REST service, I came across code duplicates.

There were 5 similar methods, whereby only the RequestBody and the Return method differed minimally.

In this case, it’s a GET request which serializes an RDF record into different formats on request.

Now I wanted to convert these 5 methods into a single method.
With the @RequestHeader annotation, this is no problem.

 @RequestMapping(value = {"/rest/**"},
        method = RequestMethod.GET)
    public @ResponseBody ResponseEntity getContainer(@RequestHeader(value="Accept") String acceptHeader, HttpServletRequest request) {

        log.debug("Request to get container: {} in format: {}", path, acceptHeader);

        // dummy code to get path
        String path = "";

        // return rdf in requested format
        return new ResponseEntity<>(containerService.find(path).toString(acceptHeader), HttpStatus.OK);

How to resolve slashes in path variable in Spring MVC

Today I stumbled across a problem where a slash can occur in a path variable.

The contents of the path variable can look like this:
1/53879d5c-b07b-44f2-9a77-b99f67bb8481 or even 1/2/53879d5c-b07b-44f2-9a77-b99f67bb8481

At the backend, I need the full path in a variable because the path can contain several slashes but does not have to.

Let’s have a look at this as a code example to make it clear.

public @ResponseBody ResponseEntity<Container> getContainerByPath(@PathVariable String path) {

  return containerService.getByPath(path);


The path /1/53879d5c-b07b-44f2-9a77-b99f67bb8481 will not work.

The solution is HttpServletRequest.

// /rest/1/53879d5c-b07b-44f2-9a77-b99f67bb8481
public @ResponseBody ResponseEntity<Container> getContainerByPath(HttpServletRequest request) {

  String path = extractPath(request);

  return containerService.getByPath(path);

private String extractPath(HttpServletRequest request) {

  String path = (String) request.getAttribute(HandlerMapping.PATH_WITHIN_HANDLER_MAPPING_ATTRIBUTE);
  String matchPattern = (String) request.getAttribute(HandlerMapping.BEST_MATCHING_PATTERN_ATTRIBUTE); // /rest/**

  return new AntPathMatcher().extractPathWithinPattern(matchPattern, path); // 1/53879d5c-b07b-44f2-9a77-b99f67bb8481




HATEOAS And HAL – And Why You Should Use It For Your REST API

Let’s face it, we all love REST. As data models grow and functionality increases, REST APIs can quickly become complex.

For the design and documentation of an API, I use Swagger.

In the screenshot, you can see an example API as shown by the Swagger UI.

There is no logical link between individual resources.


HATEOAS/HAL extends REST by the possibility to guide a user/client through.

HATEOAS is a concept of application architecture. It defines the way in which a clients application interact with the server, by navigating hypermedia links they find inside resource models returned by the server.

Since HATEOAS is only a concept, we need some standard to describe the resources, that contain hypermedia information (links to related resources).
HAL is one of such standards. It is a specific format of resource presentation, that can be used to implement HATEOAS.

For example, an answer without HATEOAS might look like this:

  "id": 1,
  "city:" "Vienna"

A client without knowledge of the possibilities of the API does not know now that he may change or delete the entry.

Let’s assume you want to tell the client that it can edit and delete this entry. With REST this is not possible.

Let’s look at the same example with implementing HATEOAS using HAL to describe the links:

URI: http://localhost:8080/api/v1/cities/1

  "id": 1,
  "city": "Vienna",
  "_links": {
    "self": {
      "href": "http://localhost:8080/api/v1/cities/1"

The first link assigned to a resource is called a self-link. It is the self-relationship – the canonical place where the resource is accessible.

This link is of course not very helpful. Let’s have a look at a more complex example: a client should change the entry “Vienna” and confirm afterwards.

The first case is simple, and CRUD provides us with the operation PUT, which usually refers to the self-link. However, how do we determine the confirmation link?
We use an additional link which we label with the label “accept”.

The client that implements the API has to check in the list of links if there is a function “accept” and follow the link.

URI: http://localhost:8080/api/v1/cities/1

  "id": 1,
  "city": "Vienna",
  "_links": {
    "self": {
      "href": "http://localhost:8080/api/v1/cities/1"
    "accept": {
      "href": "http://localhost:8080/api/v1/cities/1"


Tools and Apps I Use Every Day as a Web Developer

Every web developer has its environment, and we use so many different tools for our day-to-day workflow.

As I wrote this article, I found it very frightening how many tools I use or need. We can quickly forget about everything we depend on for our work.

Tools help us to organise and ease our daily work.

Here are my favourites.

Productivity Tools

  • Grammarly
  • Toggl
  • Google Docs
  • Google Keep

Communication Tools

  • WhatsApp Desktop
  • Telegram Desktop
  • Slack
  • Mattermost

Development and Workflow Tools

  • CMDer
  • GitHub Desktop
  • DBeaver
  • Vagrant and Docker
  • Visual Studio Code
  • PHPStorm
  • WebStorm
  • CodePen
  • Angular CLI

Google Chrome with the following apps installed

  • ColorZilla
  • JSON Formatter
  • User-Agent Switcher
  • Augury
  • Chrome Remote Desktop
  • Momentum