maven导入jar包

<repositories>

    <repository>

        <id>cloudera</id>

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

    </repository>

</repositories>

<dependencies>

    <dependency>

        <groupId>org.apache.hadoop</groupId>

        <artifactId>hadoop-common</artifactId>

        <version>2.6.0-cdh5.14.0</version>

    </dependency>

    <dependency>

        <groupId>org.apache.hive</groupId>

        <artifactId>hive-exec</artifactId>

        <version>1.1.0-cdh5.14.0</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>

     <plugin>

         <groupId>org.apache.maven.plugins</groupId>

         <artifactId>maven-shade-plugin</artifactId>

         <version>2.2</version>

         <executions>

             <execution>

                 <phase>package</phase>

                 <goals>

                     <goal>shade</goal>

                 </goals>

                 <configuration>

                     <filters>

                         <filter>

                             <artifact>*:*</artifact>

                             <excludes>

                                 <exclude>META-INF/*.SF</exclude>

                                 <exclude>META-INF/*.DSA</exclude>

                                 <exclude>META-INF/*/RSA</exclude>

                             </excludes>

                         </filter>

                     </filters>

                 </configuration>

             </execution>

         </executions>

     </plugin>

</plugins>

</build>

-------------------------------------------主程序代码------------------------------------

package com.cn;

import org.apache.hadoop.hive.ql.exec.UDF;
import org.apache.hadoop.io.Text;

/**
 * 自定义函数写法比较简单，继承UDF类，重写evaluate函数，入参为hsql的表字段，K2
 */
public class UpperFunctionDemo extends UDF {

    /**
     * 将字段转换为大写，以Text返回
     */
    public Text evaluate(Text text){
        String result = null;
        if (text != null){
            result = text.toString().toUpperCase();
            return new Text(result);
        }else{
            return null;
        }

    }
        
}

----------------------------------java代码编写完成的后续操作-------------------------------

1.将项目打包放到hive的lib目录

2.重命名我们的jar包名称（可有可无，保持包的名字规范即可）

cd /export/servers/hive-1.1.0-cdh5.14.0/lib

mv original-day_06_hive_udf-1.0-SNAPSHOT.jar udf.jar

3.hive的客户端添加我们的jar包

add jar /export/servers/hive-1.1.0-cdh5.14.0/lib/udf.jar;

4.在hive客户端内创建自定义函数，指定对应jar包，以及入口类

create temporary function tolowercase as 'cn.itcast.udf.ItcastUDF';

5.测试自定义函数

select tolowercase('abc');