Hive UDF/UDAF/UDTF Example

Some hive UDF Udaf UDTF examples originate from the Hive source code

Udf:

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     /** * Licensed to the Apache software Foundation (ASF) under one * or more C  Ontributor license agreements. See the NOTICE file * Distributed with this work for additional information * regarding copyright  Ownership. The ASF licenses this file * under the Apache License, Version 2.0 (The * "License");  You are not a use of this file except in compliance * with the License.
     
      Obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * unless required by applicable or agreed to writing, software * distributed under T He License is distributed on a "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.contrib.udf.example;
     
     Import org.apache.hadoop.hive.ql.exec.Description;
     
     
     
     Import Org.apache.hadoop.hive.ql.exec.UDF;
     
      /** * Udfexampleadd. 
     
     * */@Description (name = "Example_add", value = "_func_ (expr)-example UDAF that returns the sum")
     
         public class Udfexampleadd extends UDF {public integer evaluate (Integer ... a) {
     
         int total = 0;
     
           for (Integer element:a) {if (element! = NULL) {total + = element;
     
       }} return total;
     
         } public double evaluate (double ... a) {double total = 0;
     
           for (Double element:a) {if (element! = NULL) {total + = element;
     
         }
     
         }return total;
    
     }
     
     
     
     }

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     /**
     
      * 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