hive basic custom function

---

hive basic custom function

1. pom 文件导包
2. extends UDF 
3. class MyUDF { public String evaluate(){ return "hello evaluate"; } }
4. 打jar包
5. 上传到linux
6. 启动hadoop,hive
7. 加载jar add jar xxx.jar
8. 创建临时函数  create temporary function udf1 as 'day16.MyUDF';
9. 调用 select udf1(); ##

<properties>
	<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
	<hadoop.version>2.7.1</hadoop.version>
</properties>

<dependencies>
	<dependency>
		<groupId>org.apache.hadoop</groupId>
		<artifactId>hadoop-common</artifactId>
		<version>${hadoop.version}</version>
	</dependency>

	<dependency>
		<groupId>org.apache.hadoop</groupId>
		<artifactId>hadoop-mapreduce-client-core</artifactId>
		<version>${hadoop.version}</version>
	</dependency>
	<dependency>
		<groupId>org.apache.hadoop</groupId>
		<artifactId>hadoop-mapreduce-client-jobclient</artifactId>
		<version>${hadoop.version}</version>
	</dependency>
	<dependency>
		<groupId>org.apache.hive</groupId>
		<artifactId>hive-exec</artifactId>
		<version>1.2.1</version>
	</dependency>
	<dependency>
		<groupId>junit</groupId>
		<artifactId>junit</artifactId>
		<version>3.8.1</version>
	</dependency>
</dependencies>
<build>
	<plugins>
		<plugin>
			<groupId>org.apache.maven.plugins</groupId>
			<artifactId>maven-compiler-plugin</artifactId>
			<version>2.3.2</version>
			<configuration>
				<source>1.8</source>
				<target>1.8</target>
				<encoding>${project.build.sourceEncoding}</encoding>
			</configuration>
		</plugin>
	</plugins>
</build>