com.styra.opa.utils.OPAHTTPClient Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of opa Show documentation
SDK enabling Java developers to easily integrate with the Styra API.
There is a newer version: 1.8.0
package com.styra.opa.utils;

// This is based on the SpeakeasyHTTPClient that was generated for the Java
// SDK, but has been modified to allow injecting additional headers.

import com.styra.opa.openapi.utils.HTTPClient;

import java.io.IOException;
import java.io.InputStream;
import java.net.URISyntaxException;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import static java.net.http.HttpRequest.Builder;

/**
 * This HTTPClient implementation also injects additional headers provided to
 * its constructor into each HTTP request that it sends. This is meant to be
 * used as the HTTP client implementation for instances of the Speakeasy
 * generated OPA SDK.
 */
public class OPAHTTPClient implements HTTPClient {

    private Map headers;

    /**
     * Instantiates a new HTTP client suitable for use with the Speakeasy SDK,
     * but with additional headers included in every request.
     *
     * @param extraHeaders The extra headers to include.
     */
    public OPAHTTPClient(Map extraHeaders) {
        headers = extraHeaders;
    }

    /**
     * If instantiated with this constructor, OPAHTTPClient will be initialized
     * with an empty list of extra headers to inject.
     */
    public OPAHTTPClient() {
        headers = new HashMap();
    }

    /**
     * This method implements compatibility with the
     * com.styra.opa.sdk.utils.HTTPClient interface.
     */
    @Override
    public HttpResponse send(HttpRequest request)
            throws IOException, InterruptedException, URISyntaxException {


        // At this point, the HTTP request has already been built, so there
        // is no way to add a new header, see:
        //
        //     https://stackoverflow.com/questions/73298866/
        //
        // Consequentially, we need to make a new builder and copy all of the
        // existing request data into it.

        Builder b = HttpRequest.newBuilder(request.uri());
        b.method(
                request.method(),
                request.bodyPublisher().orElse(HttpRequest.BodyPublishers.noBody()));

        Map> existingHeaders = request.headers().map();
        for (String headerKey : existingHeaders.keySet()) {
            // .map() gives us a list of strings, but .header() only accepts
            // a scalar, so we have to do the conversion ourselves.
            String value = String.join(" ", existingHeaders.get(headerKey));
            b.header(headerKey, value);
        }

        for (String headerKey : headers.keySet()) {
            b.header(headerKey, headers.get(headerKey));
        }

        if (request.timeout().isPresent()) {
            b.timeout(request.timeout().get());
        }

        if (request.version().isPresent()) {
            b.version(request.version().get());
        }

        HttpRequest newRequest = b.build();

        HttpClient client = HttpClient.newHttpClient();

        HttpResponse response = client.send(newRequest, HttpResponse.BodyHandlers.ofInputStream());
        return response;
    }
}