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.types; 019 020import java.util.ArrayList; 021import java.util.List; 022 023import org.apache.yetus.audience.InterfaceAudience; 024 025/** 026 * A helper for building {@link Struct} instances. 027 */ 028@InterfaceAudience.Public 029public class StructBuilder { 030 031 protected final List<DataType<?>> fields = new ArrayList<>(); 032 033 /** 034 * Create an empty {@code StructBuilder}. 035 */ 036 public StructBuilder() {} 037 038 /** 039 * Append {@code field} to the sequence of accumulated fields. 040 */ 041 public StructBuilder add(DataType<?> field) { 042 fields.add(field); 043 return this; 044 } 045 046 /** 047 * Retrieve the {@link Struct} represented by {@code this}. 048 */ 049 public Struct toStruct() { 050 return new Struct(fields.toArray(new DataType<?>[fields.size()])); 051 } 052 053 /** 054 * Reset the sequence of accumulated fields. 055 */ 056 public StructBuilder reset() { 057 fields.clear(); 058 return this; 059 } 060}