001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hbase;
019
020import org.apache.yetus.audience.InterfaceAudience;
021
022/**
023 * Factory to create Tags.
024 */
025@InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.COPROC)
026public final class TagBuilderFactory {
027
028  public static TagBuilder create() {
029    return new TagBuilderImpl();
030  }
031}
032
033/**
034 * Builder implementation to create {@link Tag}<br>
035 * Call setTagValue(byte[]) method to create {@link ArrayBackedTag}
036 */
037class TagBuilderImpl implements TagBuilder {
038  // This assumes that we never create tag with value less than 0.
039  private byte tagType = (byte) -1;
040  private byte[] tagBytes = null;
041  public static final String TAG_TYPE_NOT_SET_EXCEPTION = "Need to set type of the tag.";
042  public static final String TAG_VALUE_NULL_EXCEPTION = "TagBytes can't be null";
043
044  @Override
045  public TagBuilder setTagType(byte tagType) {
046    this.tagType = tagType;
047    return this;
048  }
049
050  @Override
051  public TagBuilder setTagValue(byte[] tagBytes) {
052    this.tagBytes = tagBytes;
053    return this;
054  }
055
056  private void validate() {
057    if (tagType == -1) {
058      throw new IllegalArgumentException(TAG_TYPE_NOT_SET_EXCEPTION);
059    }
060    if (tagBytes == null) {
061      throw new IllegalArgumentException(TAG_VALUE_NULL_EXCEPTION);
062    }
063  }
064
065  @Override
066  public Tag build() {
067    validate();
068    return new ArrayBackedTag(tagType, tagBytes);
069  }
070}