Hive-UDF自定义函数-大小写转换Demo

pom.xml

<dependency>
    <groupId>org.apache.hive</groupId>
    <artifactId>hive-exec</artifactId>
</dependency>

Lower.java

public final class Lower extends UDF {
    public Text evaluate(final Text s){
        if(s==null){return null;}
        return new Text(s.toString().toLowerCase());
    }
}

测试

将代码打成 jar 包上传到服务器

add JAR /path/to/udf.jar

create temporary function tolowercase as 'cn.enjoy.hive.Lower'

select tolowercase("AAA");
select sid,tolowercase(sname),sex from person_p;