bundles/org.simantics.charts/src/org/simantics/charts/internal/JsonUtils.java

   1 package org.simantics.charts.internal;\r
   2 \r
   3 import java.io.IOException;\r
   4 import java.util.Optional;\r
   5 \r
   6 import org.simantics.db.ReadGraph;\r
   7 import org.simantics.db.RequestProcessor;\r
   8 import org.simantics.db.common.request.UniqueRead;\r
   9 import org.simantics.db.exception.DatabaseException;\r
  10 import org.simantics.db.layer0.variable.Variable;\r
  11 import org.simantics.db.layer0.variable.Variables;\r
  12 \r
  13 import com.fasterxml.jackson.core.JsonFactory;\r
  14 import com.fasterxml.jackson.core.JsonParser;\r
  15 import com.fasterxml.jackson.core.JsonToken;\r
  16 \r
  17 /**\r
  18  * @author Tuukka Lehtonen\r
  19  *\r
  20  */\r
  21 public class JsonUtils {\r
  22 \r
  23     public static Optional<Variable> tryParseJsonPropertyVariable(RequestProcessor processor, String json) throws DatabaseException {\r
  24         return processor.syncRequest(new UniqueRead<Optional<Variable>>() {\r
  25             @Override\r
  26             public Optional<Variable> perform(ReadGraph graph) throws DatabaseException {\r
  27                 return tryParseJsonPropertyVariable(graph, json);\r
  28             }\r
  29         });\r
  30     }\r
  31 \r
  32     public static Optional<Variable> tryParseJsonPropertyVariable(ReadGraph graph, String json) throws DatabaseException {\r
  33         try (JsonParser jp = new JsonFactory().createParser(json)) {\r
  34             return JsonUtils.readPossibleVariable(graph, jp);\r
  35         } catch (IOException e) {\r
  36             throw new DatabaseException(e);\r
  37         }\r
  38     }\r
  39 \r
  40     public static Optional<Variable> readPossibleVariable(ReadGraph graph, JsonParser jp) throws IOException, DatabaseException {\r
  41         Optional<String> uri = readPossibleVariableUri(jp);\r
  42         return uri.isPresent() ? Optional.ofNullable(Variables.getPossibleVariable(graph, uri.get())) : Optional.empty();\r
  43     }\r
  44 \r
  45     public static Optional<String> readPossibleVariableUri(JsonParser jp) throws IOException {\r
  46         // Sanity check: verify that we got "Json Object":\r
  47         if (jp.nextToken() != JsonToken.START_OBJECT)\r
  48             throw new IOException("Expected data to start with an Object");\r
  49 \r
  50         String uri = null;\r
  51         String type = null;\r
  52         String defaultPropertyUri = null;\r
  53 \r
  54         while (jp.nextToken() != JsonToken.END_OBJECT) {\r
  55             String fieldName = jp.getCurrentName();\r
  56             jp.nextToken();\r
  57             if (fieldName.equals("uri")) {\r
  58                 uri = jp.getValueAsString();\r
  59             } else if (fieldName.equals("type")) {\r
  60                 type = jp.getValueAsString();\r
  61             } else if (fieldName.equals("defaultPropertyUri")) {\r
  62                 defaultPropertyUri = jp.getValueAsString();\r
  63             }\r
  64         }\r
  65 \r
  66         return Optional.ofNullable("Variable".equals(type) ?\r
  67                 defaultPropertyUri != null ? defaultPropertyUri : uri\r
  68                         : null);\r
  69     }\r
  70 \r
  71 }\r