azkaban.executor.ExecutorApiClient.java Source code

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Here is the source code for azkaban.executor.ExecutorApiClient.java

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/*
 * Copyright 2015 LinkedIn Corp.
 *
 * Licensed 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 azkaban.executor;

import java.io.IOException;
import org.apache.http.HttpResponse;
import org.apache.http.StatusLine;
import org.apache.http.client.HttpResponseException;
import org.apache.http.util.EntityUtils;
import azkaban.utils.RestfulApiClient;

/** Client class that will be used to handle all Restful API calls between Executor and the host application.
 * */
public class ExecutorApiClient extends RestfulApiClient<String> {
    private static ExecutorApiClient instance = null;

    private ExecutorApiClient() {
    }

    /**
     * Singleton method to return the instance of the current object.
     * */
    public static ExecutorApiClient getInstance() {
        if (null == instance) {
            instance = new ExecutorApiClient();
        }

        return instance;
    }

    /**Implementing the parseResponse function to return de-serialized Json object.
     * @param response  the returned response from the HttpClient.
     * @return de-serialized object from Json or null if the response doesn't have a body.
     * */
    @Override
    protected String parseResponse(HttpResponse response) throws HttpResponseException, IOException {
        final StatusLine statusLine = response.getStatusLine();
        String responseBody = response.getEntity() != null ? EntityUtils.toString(response.getEntity()) : "";

        if (statusLine.getStatusCode() >= 300) {

            logger.error(String.format("unable to parse response as the response status is %s",
                    statusLine.getStatusCode()));

            throw new HttpResponseException(statusLine.getStatusCode(), responseBody);
        }

        return responseBody;
    }
}