SimpleResponseInfoValidator

It is simple wrapping builder class for java.net.http.HttpResponse.BodyHandler<T> which allows do validation if incoming http response have desired status code, headers or protocol version before receiving full http response.

A BodyHandler is a function that takes a ResponseInfo object; and which returns a BodySubscriber. The BodyHandler is invoked when the response status code and headers are available, but before the response body bytes are received.

More JDK docs

In case of unfulfilled assumptions java.io.IOException will be thrown, with one of following cause classes HttpResponseInfoHeaderException, HttpResponseInfoStatusCodeException, HttpResponseInfoVersionException.

Getting Started

Prerequisites

Gradle
JavaJDK 12+

Building

gradle build > jar should be generated in default build directory i.e. build/libs/SimpleResponseInfoValidator-1.0.jar

Usage

import java.io.IOException;
import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.util.Collections;
import java.util.Optional;

public class Example {
    public static void main(String[] args) throws IOException, InterruptedException {
        HttpClient client = HttpClient.newBuilder()
                .build();
        HttpRequest request = HttpRequest.newBuilder(URI.create("https://github.com"))
                .header("Content-Type", "text/html")
                .GET()
                .build();
        HttpResponse response = null;
        try {
            response = client.send(request, responseInfo ->
                    SimpleResponseInfoValidator.newBuilder(HttpResponse.BodyHandlers.ofString())
                            .allowedStatusCode(200)
                            .requiredHeader("Content-Type",
                                    Collections.singletonList("text/html; charset=utf-8"))
                            .expectedVersion(HttpClient.Version.HTTP_2)
                            .build()
                            .apply(responseInfo));
        } catch (IOException e) {
            Class causeClass = e.getCause().getClass();
            if (causeClass.equals(HttpResponseInfoHeaderException.class)
                    || causeClass.equals(HttpResponseInfoStatusCodeException.class)
                    || causeClass.equals(HttpResponseInfoVersionException.class))
                System.out.println("I can do special logic for wrong response info!");
            else
                throw e;
        }
        Optional.ofNullable(response)
                .ifPresent(System.out::println);
    }
}

Versioning

SemVer

License

Project is under the MIT License

Karklik / SimpleResponseInfoValidator