src/org/evergreen_ils/hatch/RequestHandler.java

   1 /* -----------------------------------------------------------------------
   2  * Copyright 2016 King County Library System
   3  * Bill Erickson <berickxx@gmail.com>
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  * -----------------------------------------------------------------------
  15  */
  16 package org.evergreen_ils.hatch;
  17
  18 import org.json.*;
  19 import java.io.File;
  20 import java.util.logging.*;
  21
  22 /**
  23  * Dispatches requests received via MessageIO, sends responses back
  24  * via MessageIO.
  25  */
  26 public class RequestHandler extends Thread {
  27
  28     /** STDIN/STDOUT handler */
  29     private static MessageIO io = new MessageIO();
  30
  31     static final Logger logger = Logger.getLogger("org.evergreen_ils.hatch");
  32
  33     /** Root directory for all FileIO operations */
  34     private static String profileDirectory = null;
  35     private static String defaultDirectory = null;
  36     private static boolean migrateProfileData = false;
  37
  38     private void configure() {
  39
  40         if (profileDirectory != null) {
  41             return; // Already loaded
  42         }
  43
  44         String home = System.getProperty("user.home");
  45         defaultDirectory = new File(home, ".evergreen").getPath();
  46         profileDirectory = Hatch.getProp("data.directory");
  47
  48         // Find the profile directory.
  49         // The profile directory + origin string represent the base
  50         // directory for all file I/O for this session.
  51         if (profileDirectory == null) {
  52             profileDirectory = defaultDirectory;
  53         } else {
  54             migrateProfileData = true;
  55         }
  56
  57         logger.info("Using data directory: " + profileDirectory);
  58
  59         if (profileDirectory == null) {
  60             logger.warning("Unable to set profile directory");
  61             return;
  62         }
  63     }
  64
  65     /**
  66      * Unpack a JSON request and send it to the necessary Hatch handler.
  67      *
  68      * @return True if the calling code should avoid calling reply() with
  69      * the response object.
  70      */
  71     private boolean dispatchRequest(
  72         JSONObject request, JSONObject response) throws JSONException {
  73
  74         String action = request.getString("action");
  75         String origin = request.getString("origin");
  76
  77         logger.info("Received message id=" +
  78             response.get("msgid") + " action=" + action);
  79
  80         if ("".equals(origin)) {
  81             response.put("status", 404);
  82             response.put("message", "'origin' parameter required");
  83             return false;
  84         }
  85
  86         String key = null;
  87         String content = null;
  88         FileIO fileIO = new FileIO(profileDirectory, origin);
  89
  90         if (migrateProfileData) {
  91             fileIO.migrateProfileData(profileDirectory, defaultDirectory, origin);
  92         }
  93
  94         switch (action) {
  95
  96             case "printers":
  97                 response.put("content",
  98                     new PrintManager().getPrintersAsMaps());
  99                 break;
 100
 101             case "printer-options":
 102
 103                 String printer = request.optString("printer", null);
 104                 JSONObject options =
 105                     new PrintManager().getPrintersOptions(printer);
 106
 107                 if (options == null) {
 108                     response.put("status", 400);
 109                     if (printer == null) {
 110                         response.put("message", "No default printer found");
 111                     } else {
 112                         response.put("message", "No such printer: " + printer);
 113                     }
 114                 } else {
 115                     response.put("content", options);
 116                 }
 117
 118                 break;
 119
 120             case "print":
 121                 // Confirm a minimal data set to enqueue print requests.
 122                 content = request.getString("content");
 123                 String contentType = request.getString("contentType");
 124
 125                 if (content == null || "".equals(content)) {
 126                     response.put("status", 400);
 127                     response.put("message", "Empty print message");
 128
 129                 } else {
 130                     Hatch.enqueuePrintRequest(request);
 131                     // Responses to print requests are generated asynchronously
 132                     // and delivered from the FX print thread via reply().
 133                     return true;
 134                 }
 135
 136             case "keys": // Return stored keys
 137                 key = request.optString("key");
 138                 response.put("content", fileIO.keys(key));
 139                 break;
 140
 141             case "get":
 142                 key = request.getString("key");
 143                 String val = fileIO.get(key);
 144
 145                 if (val != null) {
 146                     // Translate the JSON string stored by set() into a
 147                     // Java object that can be added to the response.
 148                     Object jsonBlob = new JSONTokener(val).nextValue();
 149                     response.put("content", jsonBlob);
 150                 }
 151                 break;
 152
 153             case "set" :
 154                 key = request.getString("key");
 155
 156                 // JSON-ify the thing stored under "content"
 157                 String json = JSONObject.valueToString(request.get("content"));
 158
 159                 if (!fileIO.set(key, json)) {
 160                     response.put("status", 500);
 161                     response.put("message", "Unable to set key: " + key);
 162                 }
 163                 break;
 164
 165             case "remove":
 166                 key = request.getString("key");
 167
 168                 if (!fileIO.remove(key)) {
 169                     response.put("status", 500);
 170                     response.put("message", "Unable to remove key: " + key);
 171                 }
 172                 break;
 173
 174             default:
 175                 response.put("status", 404);
 176                 response.put("message", "Action not found: " + action);
 177         }
 178
 179         return false;
 180     }
 181
 182     /**
 183      * Most replies are delivered from within dispatchRequest, but some
 184      * like printing require the reply be delivered from another thread.
 185      */
 186     protected static void reply(JSONObject response) {
 187         io.sendMessage(response);
 188     }
 189
 190     public void run() {
 191
 192         configure();
 193         io.listen(); // STDIN/STDOUT handler
 194
 195         while (true) {
 196
 197             boolean skipReply = false;
 198             JSONObject response = new JSONObject();
 199
 200             // Status values overidden as needed by the dispatch handler.
 201             response.put("status", 200);
 202             response.put("message", "OK");
 203
 204             try {
 205                 JSONObject request = io.recvMessage();
 206
 207                 response.put("clientid", request.getLong("clientid"));
 208                 response.put("msgid", request.getLong("msgid"));
 209
 210                 skipReply = dispatchRequest(request, response);
 211
 212             } catch (JSONException je) {
 213                 response.put("status", 400);
 214                 response.put("message", "Bad Request: " + je.toString());
 215             }
 216
 217             if (!skipReply) reply(response);
 218         }
 219     }
 220 }
 221