activiti-extension/src/main/java/org/onap/workflow/activitiext/restservicetask/LowLevelRestApi.java

   1 /**
   2  * Copyright 2017 [ZTE] and others.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
   5  * in compliance with the License. You may obtain a copy of the License at
   6  *
   7  * http://www.apache.org/licenses/LICENSE-2.0
   8  *
   9  * Unless required by applicable law or agreed to in writing, software distributed under the License
  10  * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
  11  * or implied. See the License for the specific language governing permissions and limitations under
  12  * the License.
  13  */
  14 package org.onap.workflow.activitiext.restservicetask;
  15
  16 import org.apache.commons.httpclient.HttpClient;
  17 import org.apache.commons.httpclient.HttpMethod;
  18 import org.slf4j.Logger;
  19 import org.slf4j.LoggerFactory;
  20
  21 import com.alibaba.fastjson.JSON;
  22
  23 /**
  24  * This static-class eases HTTP-method execution by self-managed fault-handling
  25  * and automated Response-information processing
  26  */
  27 public class LowLevelRestApi {
  28
  29         private static final Logger logger = LoggerFactory.getLogger(LowLevelRestApi.class);
  30
  31         // Local HttpClient used for every communication (Singleton implementation)
  32         private static HttpClient httpClient = new HttpClient();
  33
  34         /**
  35          * Executes a passed HttpMethod (Method type is either PUT, POST, GET or
  36          * DELETE) and returns a HttpResponseMessage
  37          *
  38          * @param method
  39          *            Method to execute
  40          * @return HttpResponseMessage which contains all information about the
  41          *         execution
  42          */
  43         public static HttpResponseMessage executeHttpMethod(HttpMethod method) throws Exception {
  44
  45                 HttpResponseMessage responseMessage = null;
  46
  47                 try {
  48
  49                         // Execute Request
  50                         LowLevelRestApi.httpClient.executeMethod(method);
  51                         responseMessage = LowLevelRestApi.extractResponseInformation(method);
  52
  53                         logger.info("statusCode: {}", method.getStatusCode());
  54                         logger.info("responseBody: {}", method.getResponseBodyAsString());
  55                 } catch (Exception e) {
  56                         logger.error("visit interface failed!", e);
  57                         throw e;
  58                 } finally {
  59
  60                         // Release Connection anyway
  61                         method.releaseConnection();
  62                 }
  63
  64                 // Extract response information and return
  65                 return responseMessage;
  66         }
  67
  68         /**
  69          * Extracts the response information from an executed HttpMethod
  70          *
  71          * @param method
  72          *            Executed Method
  73          * @return Packaged response information
  74          */
  75         private static HttpResponseMessage extractResponseInformation(HttpMethod method) {
  76                 // Create and return HttpResponseMethod
  77                 HttpResponseMessage responseMessage = new HttpResponseMessage();
  78                 responseMessage.setStatusCode(method.getStatusCode());
  79                 try {
  80                         JSON json = (JSON) JSON.parse(method.getResponseBodyAsString());
  81                         responseMessage.setResponseBody(json);
  82                         json.toJSONString();
  83                 } catch (Exception e) {
  84                         logger.info("response is not a json!");
  85                 }
  86                 return responseMessage;
  87         }
  88
  89 }