hive 之用户自定义函数

一、quickstart 项目

pom中：

<repositories>
    <repository>
      <id>cloudera</id>
      <url>https://repository.cloudera.com/artifactory/cloudera-repos/</url>
    </repository>
  </repositories>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <hive.version>1.2.1</hive.version>
    <hadoop.version>2.7.3</hadoop.version>
    <jdk.version>0.11.0.0-cp1</jdk.version>
    <junit.version>4.12</junit.version>
    <mvnshade.version>2.4.1</mvnshade.version>
    <confluent.maven.repo>http://packages.confluent.io/maven/</confluent.maven.repo>
  </properties>

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>${junit.version}</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>org.apache.hive</groupId>
      <artifactId>hive-exec</artifactId>
      <version>${hive.version}</version>
    </dependency>
    <dependency>
      <groupId>org.apache.hadoop</groupId>
      <artifactId>hadoop-common</artifactId>
      <version>${hadoop.version}</version>
    </dependency>
  </dependencies>

二、目录

package cn.kb08.udxf.udf;

public class InString extends UDF {

// 一定是evaluate方法，否则不识别
    public boolean evaluate(String str,String subStr){
        return null != str && null != subStr
                && str.length()>0 && subStr.length()<=str.length()
                && str.indexOf(subStr)>=0;
    }

}

三、发布

1）maven-package打成jar包（如果用普通方式，需要增加个文件）

2）beeline中：

add/delete jar /root/kb08/hive/hiveudxf-1.0-SNAPSHOT.jar

create/drop temporary function within as 'cn.kb08.udxf.udf.InString'

>>> 临时函数，会话结束就没了

3）show functions看看有没有within函数

4）select within('123123','123') --->  true