Java tutorial
/* * Copyright (c) 2011-2014 Jeppetto and Jonathan Thompson * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.iternine.jeppetto.dao.mongodb.enhance; import org.iternine.jeppetto.dao.JeppettoException; import com.mongodb.BasicDBList; import com.mongodb.BasicDBObject; import com.mongodb.DBObject; import java.util.Collection; import java.util.Iterator; import java.util.List; import java.util.ListIterator; import java.util.Map; import static org.iternine.jeppetto.dao.mongodb.enhance.UpdateOperation.*; public class UpdateList implements List, UpdateObject { //------------------------------------------------------------- // Variables - Private //------------------------------------------------------------- private String prefix; private UpdateOperation operation; private DBObject updates; private boolean clear = false; //------------------------------------------------------------- // Implementation - List //------------------------------------------------------------- @Override public Object set(int index, Object element) { if (clear) { throw new JeppettoException("set() after clear() not supported"); } verifyOperation($set, BasicDBObject.class); return updates.put(prefix + index, DBObjectUtil.toDBObject(element)); } @Override public boolean add(Object element) { verifyOperation($pushAll, BasicDBList.class); ((BasicDBList) updates).add(DBObjectUtil.toDBObject(element)); return true; } @Override public boolean addAll(Collection collection) { verifyOperation($pushAll, BasicDBList.class); for (Object element : collection) { ((BasicDBList) updates).add(DBObjectUtil.toDBObject(element)); } return true; } @Override public boolean remove(Object element) { if (clear) { throw new JeppettoException("remove() after clear() not supported"); } verifyOperation($pullAll, BasicDBList.class); ((BasicDBList) updates).add(DBObjectUtil.toDBObject(element)); return true; } @Override public boolean removeAll(Collection collection) { if (clear) { throw new JeppettoException("removeAll() after clear() not supported"); } verifyOperation($pullAll, BasicDBList.class); for (Object element : collection) { ((BasicDBList) updates).add(DBObjectUtil.toDBObject(element)); } return true; } @Override public void clear() { clear = true; operation = null; updates = new BasicDBList(); // When clear() is called, List-types become the only supported form. } @Override public void add(int index, Object element) { throw new JeppettoException("Can't add() an item to an UpdateList at a specific index"); } @Override public boolean addAll(int index, Collection elements) { throw new JeppettoException("Can't addAll() items to an UpdateList at a specific index"); } @Override public Object remove(int index) { throw new JeppettoException("Can't remove() an item to an UpdateList at a specific index"); } @Override public boolean retainAll(Collection collection) { throw new JeppettoException("An UpdateList does not support query operations."); } @Override public int size() { throw new JeppettoException("An UpdateList does not support query operations."); } @Override public boolean isEmpty() { throw new JeppettoException("An UpdateList does not support query operations."); } @Override public boolean contains(Object o) { throw new JeppettoException("An UpdateList does not support query operations."); } @Override public Iterator iterator() { throw new JeppettoException("An UpdateList does not support query operations."); } @Override public Object[] toArray() { throw new JeppettoException("An UpdateList does not support query operations."); } @Override public Object[] toArray(Object[] objects) { throw new JeppettoException("An UpdateList does not support query operations."); } @Override public boolean containsAll(Collection objects) { throw new JeppettoException("An UpdateList does not support query operations."); } @Override public Object get(int index) { throw new JeppettoException("An UpdateList does not support query operations."); } @Override public int indexOf(Object o) { throw new JeppettoException("An UpdateList does not support query operations."); } @Override public int lastIndexOf(Object o) { throw new JeppettoException("An UpdateList does not support query operations."); } @Override public ListIterator listIterator() { throw new JeppettoException("An UpdateList does not support query operations."); } @Override public ListIterator listIterator(final int index) { throw new JeppettoException("An UpdateList does not support query operations."); } @Override public List subList(int fromIndex, int toIndex) { throw new JeppettoException("An UpdateList does not support query operations."); } //------------------------------------------------------------- // Implementation - UpdateObject //------------------------------------------------------------- @Override public DBObject getUpdateClause() { if (clear) { // If clear() was called, updates will either be an empty BasicDBList or items added return new BasicDBObject($set.name(), new BasicDBObject(getNameFromPrefix(), updates)); } else { if (operation == null) { return new BasicDBObject(); // If there are no updates, return an empty DBObject } else if (operation == UpdateOperation.$set) { return new BasicDBObject(operation.name(), updates); } else { return new BasicDBObject(operation.name(), new BasicDBObject(getNameFromPrefix(), updates)); } } } @Override public void setPrefix(String prefix) { this.prefix = prefix; } // Temp hack @Override public Map<String, Object> __getUpdates() { return null; } //------------------------------------------------------------- // Methods - Private //------------------------------------------------------------- private void verifyOperation(UpdateOperation operation, Class<? extends DBObject> updatesClass) { if (this.operation == null) { this.operation = operation; try { this.updates = updatesClass.newInstance(); } catch (Exception e) { throw new JeppettoException(e); } } else if (this.operation != operation) { throw new JeppettoException("Can't switch operation type to '" + operation + "'. '" + this.operation + "' is already in use."); } } private String getNameFromPrefix() { return prefix.substring(0, prefix.length() - 1); } }