/tags/release-0.0.0-rc0/hive/external/ql/src/java/org/apache/hadoop/hive/ql/udf/generic/GenericUDFUnion.java
Java | 72 lines | 48 code | 7 blank | 17 comment | 3 complexity | 9b369bb0039ec668ba716ebc220bbbd7 MD5 | raw file
Possible License(s): Apache-2.0, BSD-3-Clause, JSON, CPL-1.0
- /**
- * 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.hadoop.hive.ql.udf.generic;
- import java.util.Arrays;
- import org.apache.commons.logging.Log;
- import org.apache.commons.logging.LogFactory;
- import org.apache.hadoop.hive.ql.exec.Description;
- import org.apache.hadoop.hive.ql.exec.UDFArgumentException;
- import org.apache.hadoop.hive.ql.metadata.HiveException;
- import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
- import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspectorFactory;
- import org.apache.hadoop.hive.serde2.objectinspector.StandardUnionObjectInspector.StandardUnion;
- import org.apache.hadoop.hive.serde2.objectinspector.primitive.IntObjectInspector;
- @Description(name = "create_union", value = "_FUNC_(tag, obj1, obj2, obj3, ...)"
- + " - Creates a union with the object for given tag",
- extended = "Example:\n"
- + " > SELECT _FUNC_(1, 1, \"one\") FROM src LIMIT 1;\n" + " one")
- public class GenericUDFUnion extends GenericUDF {
- Log LOG = LogFactory.getLog("GenericUDFUnion");
- ObjectInspector tagOI;
- @Override
- public ObjectInspector initialize(ObjectInspector[] arguments)
- throws UDFArgumentException {
- tagOI = arguments[0];
- ObjectInspector[] unionOIs = new ObjectInspector[arguments.length-1];
- for (int i = 1; i < arguments.length; i++) {
- unionOIs[i-1] = arguments[i];
- }
- return ObjectInspectorFactory.getStandardUnionObjectInspector(
- Arrays.asList(unionOIs));
- }
- @Override
- public Object evaluate(DeferredObject[] arguments) throws HiveException {
- byte tag = (byte)((IntObjectInspector)tagOI).get(arguments[0].get());
- return new StandardUnion(tag, arguments[tag + 1].get());
- }
- @Override
- public String getDisplayString(String[] children) {
- StringBuilder sb = new StringBuilder();
- sb.append("create_union(");
- for (int i = 0; i < children.length; i++) {
- if (i > 0) {
- sb.append(',');
- }
- sb.append(children[i]);
- }
- sb.append(')');
- return sb.toString();
- }
- }