services/dlab-webapp-common/src/main/java/com/epam/dlab/rest/client/RESTService.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package com.epam.dlab.rest.client;

import com.epam.dlab.exceptions.DlabException;
import lombok.extern.slf4j.Slf4j;

import javax.ws.rs.ProcessingException;
import javax.ws.rs.client.Client;
import javax.ws.rs.client.Entity;
import javax.ws.rs.client.Invocation;
import javax.ws.rs.client.WebTarget;
import javax.ws.rs.core.HttpHeaders;
import javax.ws.rs.core.MediaType;
import java.net.ConnectException;
import java.net.URI;
import java.util.Collections;
import java.util.Map;

@Slf4j
public class RESTService {
	private Client client;
	private String url;
	private String userAgent;

	public RESTService() {
	}

	RESTService(Client client, String url, String userAgent) {
		this.client = client;
		this.url = url;
		this.userAgent = userAgent;
	}

	RESTService(Client client, String userAgent) {
		this.client = client;
		this.userAgent = userAgent;
	}

	public <T> T get(String path, Class<T> clazz) {
		return get(path, null, clazz);
	}

	public <T> T get(URI path, Class<T> clazz) {
		log.debug("REST get {}", path);
		return client.target(URI.create(url + path.toString()))
				.request()
				.get(clazz);
	}

	public <T> T get(String path, String accessToken, Class<T> clazz) {
		Invocation.Builder builder = getBuilder(path, accessToken, Collections.emptyMap());
		log.debug("REST get secured {} {}", path, accessToken);
		return builder.get(clazz);
	}

	public <T> T post(String path, Object parameter, Class<T> clazz) {
		return post(path, null, parameter, clazz);
	}

	public <T> T post(String path, String accessToken, Object parameter, Class<T> clazz) {
		return post(path, accessToken, parameter, clazz, Collections.emptyMap());
	}

	public <T> T post(String path, String accessToken, Object parameter, Class<T> clazz,
					  Map<String, Object> queryParams) {
		Invocation.Builder builder = getBuilder(path, accessToken, queryParams);
		log.debug("REST post secured {} {}", path, accessToken);
		return builder.post(Entity.json(parameter), clazz);
	}


	private Invocation.Builder getBuilder(String path, String token, Map<String, Object> queryParams) {
		WebTarget webTarget = getWebTarget(path);
		for (Map.Entry<String, Object> entry : queryParams.entrySet()) {
			webTarget = webTarget.queryParam(entry.getKey(), entry.getValue());
		}

		Invocation.Builder builder = webTarget
				.request(MediaType.APPLICATION_JSON)
				.accept(MediaType.APPLICATION_JSON);

		if (token != null) {
			builder.header(HttpHeaders.AUTHORIZATION, "Bearer " + token);
		}

		if (userAgent != null) {
			builder.header(HttpHeaders.USER_AGENT, userAgent);
		}

		return builder;
	}

	private WebTarget getWebTarget(String path) {
		return url != null ?
				client.target(url).path(path) : client.target(path);
	}
}