Hive中UDAF简单实现

最新推荐文章于 2025-05-29 23:38:09 发布

神罗天征-长门

最新推荐文章于 2025-05-29 23:38:09 发布

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分类专栏： hive 文章标签： hive udaf

本文链接：https://blog.youkuaiyun.com/dwt1415403329/article/details/99617819

需求：一个score表，就一个字段score，求其avg

1>建表语句以及其数据

create table test_score(
score bigint
);


10
30
25
25
9

2>具体实现代码

package com.hnxy.function;

import org.apache.hadoop.hive.ql.exec.UDFArgumentException;
import org.apache.hadoop.hive.ql.metadata.HiveException;
import org.apache.hadoop.hive.ql.parse.SemanticException;
import org.apache.hadoop.hive.ql.udf.generic.AbstractGenericUDAFResolver;
import org.apache.hadoop.hive.ql.udf.generic.GenericUDAFEvaluator;
import org.apache.hadoop.hive.serde2.lazybinary.LazyBinaryStruct;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspectorFactory;
import org.apache.hadoop.hive.serde2.objectinspector.PrimitiveObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.primitive.Primitiv