POLICY-SDK-APP/src/main/java/org/onap/policy/utils/ConfigurableRESTUtils.java

   1 /*-
   2  * ============LICENSE_START=======================================================
   3  * ONAP Policy Engine
   4  * ================================================================================
   5  * Copyright (C) 2017 AT&T Intellectual Property. All rights reserved.
   6  * ================================================================================
   7  * Licensed under the Apache License, Version 2.0 (the "License");
   8  * you may not use this file except in compliance with the License.
   9  * You may obtain a copy of the License at
  10  *
  11  *      http://www.apache.org/licenses/LICENSE-2.0
  12  *
  13  * Unless required by applicable law or agreed to in writing, software
  14  * distributed under the License is distributed on an "AS IS" BASIS,
  15  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  16  * See the License for the specific language governing permissions and
  17  * limitations under the License.
  18  * ============LICENSE_END=========================================================
  19  */
  20
  21 package org.onap.policy.utils;
  22
  23
  24 import java.io.IOException;
  25 import java.io.InputStream;
  26 import java.io.OutputStreamWriter;
  27 import java.net.HttpURLConnection;
  28 import java.net.URL;
  29 import java.util.Map;
  30 import java.util.Map.Entry;
  31
  32 import org.onap.policy.common.logging.flexlogger.FlexLogger;
  33 import org.onap.policy.common.logging.flexlogger.Logger;
  34
  35
  36 public class ConfigurableRESTUtils  {
  37
  38         protected Logger LOGGER = FlexLogger.getLogger(this.getClass());
  39
  40         //
  41         // How the value is returned from the RESTful server
  42         //              httpResponseCode means the result is simply the HTTP Response code (e.g. 200, 505, etc.)
  43         //              other values identify the encoding used for the string in the body of the HTTP response
  44         //
  45         public enum REST_RESPONSE_FORMAT {httpResponseCode, json }
  46         public enum RESQUEST_METHOD {
  47                   GET, HEAD, POST, PUT, PATCH, DELETE, OPTIONS, TRACE;
  48                 }
  49
  50         private String ERROR_RECEIVED = "ERROR - Unexpected HTTP response: ";
  51
  52         public ConfigurableRESTUtils() {
  53                 //Default Constructor
  54         }
  55
  56
  57         /**
  58          * Call the RESTful API and return a string containing the result.  The string may be either a httpResponseCode or json body
  59          *
  60          * @param fullURI
  61          * @param hardCodedHeaders
  62          * @param httpResponseCodes
  63          * @param responseFormat
  64          * @param jsonBody
  65          * @param requestMethod
  66          * @return String
  67          */
  68         public String sendRESTRequest(String fullURI, Map<String, String> hardCodedHeaderMap,
  69                         Map<Integer,String> httpResponseCodeMap,
  70                         REST_RESPONSE_FORMAT responseFormat,
  71                         String jsonBody,
  72                         RESQUEST_METHOD requestMethod ){
  73
  74                 String responseString = null;
  75                 HttpURLConnection connection = null;
  76                 try {
  77
  78                         URL url = new URL(fullURI);
  79
  80                         //
  81                         // Open up the connection
  82                         //
  83                         connection = (HttpURLConnection)url.openConnection();
  84                         //
  85                         // Setup our method and headers
  86                         //
  87             connection.setRequestMethod(requestMethod.toString());
  88
  89             connection.setUseCaches(false);
  90
  91             // add hard-coded headers
  92             for (Entry<String, String> entry : hardCodedHeaderMap.entrySet()) {
  93                 connection.addRequestProperty(entry.getKey(), entry.getValue());
  94             }
  95
  96             if (jsonBody != null){
  97                 connection.setDoInput(true);
  98                 connection.setDoOutput(true);
  99                         OutputStreamWriter out = new OutputStreamWriter(connection.getOutputStream());
 100                         out.write(jsonBody);
 101                         out.flush();
 102                         out.close();
 103             } else{
 104                 connection.connect();
 105             }
 106
 107             int responseCode = connection.getResponseCode();
 108
 109             // check that the response is one we expected (and get the associated value at the same time)
 110             responseString = httpResponseCodeMap.get(responseCode);
 111             if (responseString == null) {
 112                 // the response was not configured, meaning it is unexpected and therefore an error
 113                 LOGGER.error("Unexpected HTTP response code '" + responseCode + "' from RESTful Server");
 114                 return ERROR_RECEIVED +  " code" + responseCode + " from RESTful Server";
 115             }
 116
 117             // if the response is contained only in the http code we are done.  Otherwise we need to read the body
 118             if (responseFormat == REST_RESPONSE_FORMAT.httpResponseCode) {
 119                 return responseString;
 120             }
 121
 122             // Need to read the body and return that as the responseString.
 123
 124             responseString = null;
 125                         // read the inputStream into a buffer (trick found online scans entire input looking for end-of-file)
 126                     java.util.Scanner scanner = new java.util.Scanner(connection.getInputStream());
 127                     scanner.useDelimiter("\\A");
 128                     responseString =  scanner.hasNext() ? scanner.next() : "";
 129                     scanner.close();
 130                     LOGGER.debug("RESTful body: " + responseString);
 131                     return responseString;
 132
 133                 } catch (Exception e) {
 134                         LOGGER.error("HTTP Request/Response from RESTFUL server: " + e);
 135                         responseString =  ERROR_RECEIVED + e;
 136                 } finally {
 137                         // cleanup the connection
 138                                 if (connection != null) {
 139                                 try {
 140                                         // For some reason trying to get the inputStream from the connection
 141                                         // throws an exception rather than returning null when the InputStream does not exist.
 142                                         InputStream is = null;
 143                                         try {
 144                                                 is = connection.getInputStream();
 145                                         } catch (Exception e1) {
 146                                                 LOGGER.error("Exception Occured"+e1);
 147                                         }
 148                                         if (is != null) {
 149                                                 is.close();
 150                                         }
 151
 152                                 } catch (IOException ex) {
 153                                         LOGGER.error("Failed to close connection: " + ex, ex);
 154                                 }
 155                                 connection.disconnect();
 156                         }
 157                 }
 158                 return responseString;
 159
 160         }
 161
 162 }