Android Open Source - DKO Soft Join Util

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License

The source code is released under:
GNU Lesser General Public License
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Java Source Code

package org.kered.dko;
//  w  w w  . j  a v  a2 s. c o m
import java.util.ArrayList;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.kered.dko.Condition.Binary;
import org.kered.dko.Condition.Binary2;
import org.kered.dko.Field.PK;

class SoftJoinUtil {

  static Map<Field<?>,Field<?>> getFieldsOpposingPK(Class<? extends Table> type, Condition condition) {
    PK<? extends Table> pk = Util.getPK(type);
    if (pk==null) return null;
    Set<Field<?>> pkFields = new HashSet<Field<?>>(pk.GET_FIELDS());
    Map<Field<?>,Field<?>> otherFields = new LinkedHashMap<Field<?>,Field<?>>();
    List<Condition> conditions;
    if (condition instanceof Condition.And) {
      conditions = ((Condition.And)condition).conditions;
    } else {
      conditions = new ArrayList<Condition>();
      conditions.add(condition);
    }
    for (Condition c : conditions) {
      if (c instanceof Binary) {
        Binary bc = (Binary)c;
        if (bc.cmp!=null && "=".equals(bc.cmp.trim())) {
          if (pkFields.contains(bc.field) && bc.field2!=null) otherFields.put(bc.field, bc.field2);
          if (pkFields.contains(bc.field2) && bc.field!=null) otherFields.put(bc.field2, bc.field);
          pkFields.remove(bc.field);
          pkFields.remove(bc.field2);
        }
      }
      if (c instanceof Binary2) {
        Binary2 bc = (Binary2)c;
        if (bc.cmp!=null && "=".equals(bc.cmp.trim())) {
          if (pkFields.contains(bc.o1) && bc.o2 instanceof Field) otherFields.put((Field<?>) bc.o1, (Field<?>) bc.o2);
          if (pkFields.contains(bc.o2) && bc.o1 instanceof Field) otherFields.put((Field<?>) bc.o2, (Field<?>) bc.o1);
          pkFields.remove(bc.o1);
          pkFields.remove(bc.o2);
        }
      }
    }
    return otherFields;
  }

  static boolean doesConditionCoverPK(Class<? extends Table> type, Condition condition) {
    PK<? extends Table> pk = Util.getPK(type);
    if (pk==null) return false;
    Set<Field<?>> fields = new HashSet<Field<?>>(pk.GET_FIELDS());
    List<Condition> conditions;
    if (condition instanceof Condition.And) {
      conditions = ((Condition.And)condition).conditions;
    } else {
      conditions = new ArrayList<Condition>();
      conditions.add(condition);
    }
    for (Condition c : conditions) {
      if (c instanceof Binary) {
        Binary bc = (Binary)c;
        if (bc.cmp!=null && "=".equals(bc.cmp.trim())) {
          fields.remove(bc.field);
          fields.remove(bc.field2);
        }
      }
      if (c instanceof Binary2) {
        Binary2 bc = (Binary2)c;
        if (bc.cmp!=null && "=".equals(bc.cmp.trim())) {
          fields.remove(bc.o1);
          fields.remove(bc.o2);
        }
      }
    }
    return fields.isEmpty();
  }

  static int getObjectSizeOfQuery(final Query<? extends Table> q) {
    try {
      final java.lang.reflect.Field f = q.getClass().getDeclaredField("SIZE");
      return f.getInt(q);
    } catch (final NoSuchFieldException e) {
      // not a Join._Query
      return 1;
    } catch (final Exception e) {
      throw new RuntimeException(e);
    }
  }
  
  static class AddNullAtEnd<E extends Table> implements Iterable<E> {
    private Query<E> q;
    public AddNullAtEnd(Query<E> q) {
      this.q = q;
    }
    @Override
    public Iterator<E> iterator() {
      final Iterator<E> i = q.iterator();
      return new Iterator<E>() {
        boolean sentLastNull = false;
        @Override
        public boolean hasNext() {
          return i.hasNext() || !sentLastNull;
        }
        @Override
        public E next() {
          if (i.hasNext()) return i.next();
          sentLastNull = true;
          return null;
        }
        @Override
        public void remove() {
          i.remove();
        }
      };
    }

  }

  static boolean conditionIsAllReferencingQuery(final Condition condition,
      final Query<? extends Table> q) {
    if (!(q instanceof DBQuery))
      return false;
    try {
      final DBQuery<? extends Table> q2 = (DBQuery<? extends Table>) q
          .where(condition);
      final SqlContext context = new SqlContext(q2);
      q2.getWhereClauseAndBindings(context);
      return true;
    } catch (final Util.FieldNotPartOfSelectableTableSet e) {
      return false;
    }
  }


}
Java Source Code List
