Java http client example
#Java http client example software#
The method can process or discard the response (because of code fault of whatever other reason software engineer meant). BodyHandler is the class you need especially when handling asynchronous request - it puts HttpResponse.ResponseInfo object through this function interface.
This guy depends on BodySubscriber class which transforms List of response body into whatever class is needed. Generic class depends on HttpResponse.BodyHandler instance provided in HttpClient::send or HttpClient::sendAsync. The good part of BodyPublishers methods is a possibility to reuse existing Flow.Publisher object with fromPublisher method. Providing a key-value map as a body doesn’t work here (by default). It applies especially to url-encoded ones. I found this difficult to send form-alike data. In my case above, I used BodyPublishers.ofString(urlEncodedBody). Software engineers or architects might consider using this concept in their own API instead of homemade sub-pub layers.Īnyway, if one is looking for ready-to-use publishers (no one wants to write one), a few are located in HttpRequest.BodyPublishers class. The entire concept of subscriber/publisher used in the API is worth exploring and I recommend you to see the documentation about Publishers from package. It feeds body content with some value using (primarily) a ByteBuffer. The other important subclass here is HttpRequest.BodyPublisher. The example is trivial, however more complex expressions like passing through the HTTP builder for some dynamic operations seem legitimate to me. Two different methods don’t have to declare the specific header twice. header ( "SomeSpecificHeaderIHaveToUseThere", "ValueOfThisHeader" ) HttpRequest. The main advantage of this approach is using a copy() method for creating more than one instance of request (however the one request can be used many times) - for example: HttpRequest. The request is also immutable and created through the builder pattern. The HTTP request is created by newBuilder methods. All configuration parameters and HttpClient instantiation have to be provided by HttpClient.Builder class. Because of the good object-oriented design, the HttpClient’s constructor is protected. You can set up here a connection like proxy, SSL setup, following redirects (or not) and authentication.
How the new HTTP Client Java API is different from other HTTP clients? Here is the test code: public void shouldReturn404OnWrongRequest () throws Exception Īdvantages? Fluent API, an actual result (not a mutable request object).ĭisadvantages? Lack of urlencoded handling on its own. In order to test it, Apache http-commons library (which is an actual better version of Apache’s HttpClient API in every sense) was doing the HTTP work for me. Recently, I wrote an example newsletter service - which is, by the way, used in this blog. HTTP client API was de-incubated in Java 11 and guess what? It looks nice. I had to try it on my own in the home laboratory.
When the HTTP client was introduced and incubated in Java 9 I was like:įinally, we have our HTTP client, at least for testing!. Projects use Apache HttpClient API for trivial tasks like testing, which I consider as a brain rape because of the usage difficulties. Comparing to other technologies like Groovy which have built-in APIs, Java sucks. Any HTTP Client library in Java is a hell to me.