bundles/org.simantics.db.impl/src/org/simantics/db/impl/graph/SingleObjectProcedure.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 SingleObjectProcedure implements IntProcedure {\r
  10 \r
  11         final private QueryProcessor processor;\r
  12         private DatabaseException exception;\r
  13         private Resource result;\r
  14         \r
  15         public SingleObjectProcedure(QueryProcessor processor) {\r
  16                 this.processor = processor;\r
  17         }\r
  18         \r
  19         @Override\r
  20         public void execute(ReadGraphImpl graph, int i) {\r
  21                 Resource resource = processor.querySupport.getResource(i);\r
  22                 if(result != null) {\r
  23                         exception = new NoSingleResultException("");\r
  24                 } else {\r
  25                         result = resource;\r
  26                 }\r
  27         }\r
  28 \r
  29         @Override\r
  30         public void finished(ReadGraphImpl graph) {\r
  31                 if(result == null) exception = new NoSingleResultException("");\r
  32         }\r
  33 \r
  34         @Override\r
  35         public void exception(ReadGraphImpl graph, Throwable throwable) {\r
  36                 if(throwable instanceof DatabaseException) exception = (DatabaseException)throwable;\r
  37                 else throwable = new DatabaseException(throwable);\r
  38         }\r
  39         \r
  40         public Resource get() throws DatabaseException {\r
  41                 if(exception != null) throw exception;\r
  42                 else return result;\r
  43         }\r
  44 \r
  45 }\r