hive自定义函数

pom文件

  <dependencies>
        <dependency>
            <groupId>org.apache.hive</groupId>
            <artifactId>hive-exec</artifactId>
            <version>3.0.0</version>
        </dependency>
        <dependency>
            <groupId>org.apache.hadoop</groupId>
            <artifactId>hadoop-common</artifactId>
            <version>3.0.0</version>
        </dependency>
    </dependencies>


    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.0</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                    <encoding>UTF-8</encoding>
                </configuration>
            </plugin>

        </plugins>

    </build>

生成0-15随机数java代码

import org.apache.hadoop.hive.ql.exec.UDF;
import java.util.Random;


public class RandomUDF extends UDF {
    public int evaluate(String str) {
        Random random = new Random();
        int i = random.nextInt(16);
        return i;
    }


    public static void main(String[] args) {
        RandomUDF randomUDF=new RandomUDF();
        System.out.println(randomUDF.evaluate("fff"));

    }

}

上传hdfs目录

hdfs dfs -put /tmp/hiveudf16.jar hdfs:///tmp/

在impala创建函数或在hue界面

create function if not exists getuuid(STRING) returns int location 'hdfs:///tmp/hiveudf16.jar' symbol='com.sunward.hive.RandomUDF';

 删除自定义函数

drop function getuuid(STRING);