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

   1 /**
   2  * Copyright 2017 ZTE Corporation.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16 package org.onap.workflow.activitiext.restservicetask;
  17
  18 import org.apache.commons.httpclient.HttpClient;
  19 import org.apache.commons.httpclient.HttpMethod;
  20 import org.slf4j.Logger;
  21 import org.slf4j.LoggerFactory;
  22
  23 import com.alibaba.fastjson.JSON;
  24
  25 /**
  26  * This static-class eases HTTP-method execution by self-managed fault-handling
  27  * and automated Response-information processing
  28  */
  29 public class LowLevelRestApi {
  30
  31         private static final Logger logger = LoggerFactory.getLogger(LowLevelRestApi.class);
  32
  33         // Local HttpClient used for every communication (Singleton implementation)
  34         private static HttpClient httpClient = new HttpClient();
  35
  36         /**
  37          * Executes a passed HttpMethod (Method type is either PUT, POST, GET or
  38          * DELETE) and returns a HttpResponseMessage
  39          *
  40          * @param method
  41          *            Method to execute
  42          * @return HttpResponseMessage which contains all information about the
  43          *         execution
  44          */
  45         public static HttpResponseMessage executeHttpMethod(HttpMethod method) throws Exception {
  46
  47                 HttpResponseMessage responseMessage = null;
  48
  49                 try {
  50
  51                         // Execute Request
  52                         LowLevelRestApi.httpClient.executeMethod(method);
  53                         responseMessage = LowLevelRestApi.extractResponseInformation(method);
  54
  55                         logger.info("statusCode: {}", method.getStatusCode());
  56                         logger.info("responseBody: {}", method.getResponseBodyAsString());
  57                 } catch (Exception e) {
  58                         logger.error("visit interface failed!", e);
  59                         throw e;
  60                 } finally {
  61
  62                         // Release Connection anyway
  63                         method.releaseConnection();
  64                 }
  65
  66                 // Extract response information and return
  67                 return responseMessage;
  68         }
  69
  70         /**
  71          * Extracts the response information from an executed HttpMethod
  72          *
  73          * @param method
  74          *            Executed Method
  75          * @return Packaged response information
  76          */
  77         private static HttpResponseMessage extractResponseInformation(HttpMethod method) {
  78                 // Create and return HttpResponseMethod
  79                 HttpResponseMessage responseMessage = new HttpResponseMessage();
  80                 responseMessage.setStatusCode(method.getStatusCode());
  81                 try {
  82                         JSON json = (JSON) JSON.parse(method.getResponseBodyAsString());
  83                         responseMessage.setResponseBody(json);
  84                         json.toJSONString();
  85                 } catch (Exception e) {
  86                         logger.info("response is not a json!");
  87                 }
  88                 return responseMessage;
  89         }
  90
  91 }