1 /**
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
17 */
18 package org.apache.hadoop.hbase.types;
19
20 import java.util.ArrayList;
21 import java.util.List;
22
23 import org.apache.hadoop.hbase.classification.InterfaceAudience;
24 import org.apache.hadoop.hbase.classification.InterfaceStability;
25
26 /**
27 * A helper for building {@link Struct} instances.
28 */
29 @InterfaceAudience.Public
30 @InterfaceStability.Evolving
31 public class StructBuilder {
32
33 protected final List<DataType<?>> fields = new ArrayList<DataType<?>>();
34
35 /**
36 * Create an empty {@code StructBuilder}.
37 */
38 public StructBuilder() {}
39
40 /**
41 * Append {@code field} to the sequence of accumulated fields.
42 */
43 public StructBuilder add(DataType<?> field) { fields.add(field); return this; }
44
45 /**
46 * Retrieve the {@link Struct} represented by {@code this}.
47 */
48 public Struct toStruct() { return new Struct(fields.toArray(new DataType<?>[fields.size()])); }
49
50 /**
51 * Reset the sequence of accumulated fields.
52 */
53 public StructBuilder reset() { fields.clear(); return this; }
54 }