bundles/org.simantics.db.impl/src/org/simantics/db/impl/graph/PossibleObjectProcedure.java

   1 package org.simantics.db.impl.graph;\r
   2 \r
   3 import org.simantics.db.Resource;\r
   4 import org.simantics.db.exception.DatabaseException;\r
   5 import org.simantics.db.exception.NoSingleResultException;\r
   6 import org.simantics.db.impl.query.IntProcedure;\r
   7 import org.simantics.db.impl.query.QueryProcessor;\r
   8 \r
   9 public class PossibleObjectProcedure implements IntProcedure {\r
  10 \r
  11         private static DatabaseException DUMMY = new DatabaseException();\r
  12         \r
  13         final private QueryProcessor processor;\r
  14         private DatabaseException exception;\r
  15         private Resource result;\r
  16         \r
  17         public PossibleObjectProcedure(QueryProcessor processor) {\r
  18                 this.processor = processor;\r
  19         }\r
  20         \r
  21         @Override\r
  22         public void execute(ReadGraphImpl graph, int i) {\r
  23                 Resource resource = processor.querySupport.getResource(i);\r
  24                 if(result != null) {\r
  25                         exception = DUMMY;\r
  26                 } else {\r
  27                         result = resource;\r
  28                 }\r
  29         }\r
  30 \r
  31         @Override\r
  32         public void finished(ReadGraphImpl graph) {\r
  33         }\r
  34 \r
  35         @Override\r
  36         public void exception(ReadGraphImpl graph, Throwable throwable) {\r
  37                 if(throwable instanceof DatabaseException) exception = (DatabaseException)throwable;\r
  38                 else throwable = new DatabaseException(throwable);\r
  39         }\r
  40         \r
  41         public Resource get() throws DatabaseException {\r
  42                 if(exception == DUMMY) return null;\r
  43                 else if(exception != null) throw exception;\r
  44                 else return result;\r
  45         }\r
  46 \r
  47 }\r