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

   1 package org.simantics.db.impl.graph;
   2
   3 import org.simantics.db.Resource;
   4 import org.simantics.db.exception.DatabaseException;
   5 import org.simantics.db.exception.NoSingleResultException;
   6 import org.simantics.db.impl.query.IntProcedure;
   7 import org.simantics.db.impl.query.QueryProcessor;
   8
   9 public class SingleObjectProcedure implements IntProcedure {
  10
  11         final private QueryProcessor processor;
  12         private DatabaseException exception;
  13         private Resource result;
  14
  15         public SingleObjectProcedure(QueryProcessor processor) {
  16                 this.processor = processor;
  17         }
  18
  19         @Override
  20         public void execute(ReadGraphImpl graph, int i) {
  21                 Resource resource = processor.querySupport.getResource(i);
  22                 if(result != null) {
  23                         exception = new NoSingleResultException("", 2);
  24                 } else {
  25                         result = resource;
  26                 }
  27         }
  28
  29         @Override
  30         public void finished(ReadGraphImpl graph) {
  31                 if(result == null) exception = new NoSingleResultException("", 0);
  32         }
  33
  34         @Override
  35         public void exception(ReadGraphImpl graph, Throwable throwable) {
  36                 if(throwable instanceof DatabaseException) exception = (DatabaseException)throwable;
  37                 else throwable = new DatabaseException(throwable);
  38         }
  39
  40         public Resource get() throws DatabaseException {
  41                 if(exception != null) throw exception;
  42                 else return result;
  43         }
  44
  45 }