add HttpClient powered by OkHttp

Author: niemannd

build.gradle

@@ -36,7 +36,8 @@ dependencies {
 	implementation 'com.google.code.gson:gson:2.8.6'
 	implementation 'org.json:json:20200518'
 	// https://mvnrepository.com/artifact/org.apache.httpcomponents.client5/httpclient5
-	compileOnly group: 'org.apache.httpcomponents.client5', name: 'httpclient5', version: '5.0.2'
+	compileOnly group: 'org.apache.httpcomponents.client5', name: 'httpclient5', version: '5.0.3'
+	compileOnly 'com.squareup.okhttp3:okhttp:4.9.0'
 
 	// Use JUnit test framework
 	testImplementation(platform('org.junit:junit-bom:5.7.0'))

src/main/java/com/meilisearch/sdk/http/OkHttpHttpClient.java

@@ -0,0 +1,114 @@
+package com.meilisearch.sdk.http;
+
+import com.meilisearch.sdk.Config;
+import com.meilisearch.sdk.http.request.HttpRequest;
+import com.meilisearch.sdk.http.response.BasicHttpResponse;
+import com.meilisearch.sdk.http.response.HttpResponse;
+import okhttp3.*;
+
+import java.io.IOException;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+public class OkHttpHttpClient extends AbstractHttpClient {
+	private static final MediaType JSON = MediaType.get("application/json; charset=utf-8");
+	private static final RequestBody EMPTY_REQUEST_BODY = RequestBody.create("".getBytes());
+	private final OkHttpClient client;
+
+	public OkHttpHttpClient(Config config, OkHttpClient client) {
+		super(config);
+		this.client = client;
+	}
+
+	public OkHttpHttpClient(Config config) {
+		super(config);
+		this.client = new OkHttpClient();
+	}
+
+	private RequestBody getBodyFromRequest(HttpRequest<?> request) {
+		if (request.hasContent())
+			return RequestBody.create(request.getContentAsBytes(), JSON);
+		return EMPTY_REQUEST_BODY;
+	}
+
+	private Request buildRequest(HttpRequest<?> request) throws MalformedURLException {
+		URL url = new URL(this.config.getHostUrl() + request.getPath());
+		Request.Builder builder = new Request.Builder();
+		builder.url(url);
+		if (this.config.getApiKey() != null)
+			builder.addHeader("X-Meili-API-Key", this.config.getApiKey());
+		switch (request.getMethod()) {
+			case GET:
+				builder.get();
+				break;
+			case POST:
+				builder.post(getBodyFromRequest(request));
+				break;
+			case PUT:
+				builder.put(getBodyFromRequest(request));
+				break;
+			case DELETE:
+				if (request.hasContent())
+					builder.delete(getBodyFromRequest(request));
+				else
+					builder.delete();
+				break;
+			default:
+				throw new IllegalStateException("Unexpected value: " + request.getMethod());
+		}
+
+		return builder.build();
+	}
+
+	private HttpResponse<?> buildResponse(Response response) throws IOException {
+		String body = null;
+		ResponseBody responseBody = response.body();
+		if (responseBody != null)
+			body = responseBody.string();
+
+		return new BasicHttpResponse(
+			parseHeaders(response.headers().toMultimap()),
+			response.code(),
+			body
+		);
+	}
+
+	private Map<String, String> parseHeaders(Map<String, List<String>> headers) {
+		HashMap<String, String> headerMap = new HashMap<>();
+		for (Map.Entry<String, List<String>> entry : headers.entrySet()) {
+			headerMap.put(entry.getKey(), String.join("; ", entry.getValue()));
+		}
+		return headerMap;
+	}
+
+	@Override
+	public HttpResponse<?> get(HttpRequest<?> request) throws Exception {
+		Request okRequest = buildRequest(request);
+		Response execute = client.newCall(okRequest).execute();
+		return buildResponse(execute);
+	}
+
+	@Override
+	public HttpResponse<?> post(HttpRequest<?> request) throws Exception {
+		Request okRequest = buildRequest(request);
+		Response execute = client.newCall(okRequest).execute();
+		return buildResponse(execute);
+	}
+
+	@Override
+	public HttpResponse<?> put(HttpRequest<?> request) throws Exception {
+		Request okRequest = buildRequest(request);
+		Response execute = client.newCall(okRequest).execute();
+		return buildResponse(execute);
+	}
+
+	@Override
+	public HttpResponse<?> delete(HttpRequest<?> request) throws Exception {
+		Request okRequest = buildRequest(request);
+		Response execute = client.newCall(okRequest).execute();
+		return buildResponse(execute);
+	}
+}