hive/execution/UDFListString.java

0001 /*
0002  * Licensed to the Apache Software Foundation (ASF) under one or more
0003  * contributor license agreements.  See the NOTICE file distributed with
0004  * this work for additional information regarding copyright ownership.
0005  * The ASF licenses this file to You under the Apache License, Version 2.0
0006  * (the "License"); you may not use this file except in compliance with
0007  * the License.  You may obtain a copy of the License at
0008  *
0009  *    http://www.apache.org/licenses/LICENSE-2.0
0010  *
0011  * Unless required by applicable law or agreed to in writing, software
0012  * distributed under the License is distributed on an "AS IS" BASIS,
0013  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
0014  * See the License for the specific language governing permissions and
0015  * limitations under the License.
0016  */
0017
0018 package org.apache.spark.sql.hive.execution;
0019
0020 import java.util.List;
0021
0022 import org.apache.commons.lang3.StringUtils;
0023 import org.apache.hadoop.hive.ql.exec.UDF;
0024
0025 public class UDFListString extends UDF {
0026
0027   public String evaluate(Object a) {
0028     if (a == null) {
0029       return null;
0030     }
0031     @SuppressWarnings("unchecked")
0032     List<Object> s = (List<Object>) a;
0033
0034     return StringUtils.join(s, ',');
0035   }
0036
0037
0038 }