Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You 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.apache.jackrabbit.oak.plugins.document.mongo; import java.util.Collections; import java.util.Map; import java.util.Set; import javax.annotation.Nonnull; import javax.annotation.Nullable; import org.apache.jackrabbit.oak.plugins.document.Revision; import org.bson.BSONObject; import com.mongodb.DBObject; import com.mongodb.util.JSON; import static com.google.common.base.Preconditions.checkNotNull; /** * A light-weight implementation of a MongoDB DBObject for a single revision * based map entry. */ public class RevisionEntry implements DBObject { private final Revision revision; private final Object value; public RevisionEntry(@Nonnull Revision revision, @Nullable Object value) { this.revision = checkNotNull(revision); this.value = value; } @Override public void markAsPartialObject() { } @Override public boolean isPartialObject() { return false; } @Override public Object put(String key, Object v) { throw new UnsupportedOperationException(); } @Override public void putAll(BSONObject o) { throw new UnsupportedOperationException(); } @Override public void putAll(Map m) { throw new UnsupportedOperationException(); } @Override public Object get(String key) { return revision.toString().equals(key) ? value : null; } @Override public Map toMap() { return Collections.singletonMap(revision.toString(), value); } @Override public Object removeField(String key) { throw new UnsupportedOperationException(); } @Override public boolean containsKey(String s) { return containsField(s); } @Override public boolean containsField(String s) { return revision.toString().equals(s); } @Override public Set<String> keySet() { return Collections.singleton(revision.toString()); } @Override public String toString() { return JSON.serialize(this); } }