目录
- 🍑一、UDF(User Defined Function:用户定义函数)
- 🍊1.1、继承UDF函数
- 🍓1.1.1、pom.xml 引入hive执行包
- 🍓1.1.2、MaskUDF 实现掩码函数
- 🍓1.1.3、打包放到hive环境
- 🍒hive-env.sh配置jar包路径
- 🍓1.1.4、创建临时函数测试
- 🍓1.1.5、验证
- 🍊1.2、继承GenericUDF函数
- 🍓1.2.1、直接编写CutOffUDF 实现截取函数,其它同UDF步骤
- 🍓1.2.2、测试
- 🍑二、JDBC连接测试
- 🍊2.1、创建表及数据
- 🍊2.2、创建正式函数
- 🍊2.3、JDBC连接工具类及驱动引入
- 🍓2.3.1、HiveJDBCUtil
- 🍓2.3.2、pom.xml引入hive-jdbc驱动
- 🍊2.4、UDF测试类
- 🍓2.4.1、UdfUseDemo
- 🍓2.4.2、测试结果
- 🍒2.4.2.1、截断函数报错
- 🍒2.4.2.2、原因-类型不匹配
- 🍇2.4.2.2.1、修改字段类型
- 🍇2.4.2.2.2、再次验证
- 🍑三、其他
- 🍊源码下载
🍑一、UDF(User Defined Function:用户定义函数)
Hive本身内置大量用户函数UDF 来操作时间、字符串和其他的数据挖掘工具,同时也支持用户扩展UDF 函数来完成内置函数无法实现的操作。官网API
🍊1.1、继承UDF函数
继承UDF类,实现简单,只需要重写evaluate方法(该方法必须返回String类型)读取和返回基本类型,但是在hive3.0版本中,已不建议使用该类,推荐使用
GenericUDF
🍓1.1.1、pom.xml 引入hive执行包
<dependency>
<groupId>org.apache.hive</groupId>
<artifactId>hive-exec</artifactId>
<version>3.1.0</version>
</dependency>
🍓1.1.2、MaskUDF 实现掩码函数
3.0开始已不建议使用:
源码:
package com.renxiaozhao.udf;
import org.apache.hadoop.hive.ql.exec.UDF;
import org.apache.hadoop.hive.ql.metadata.HiveException;
/**
* 掩码函数.
* @author rxz 20220808
*
*/
@SuppressWarnings("deprecation")
public class MaskUDF extends UDF {
private static final int MASK_LEFT = 0;//掩码从左至右标识
private static final int MASK_RIGHT = -1;//掩码从右至左标识
/**
* 掩码处理.
* @param input 掩码输入参数
* @param startIndex 掩码从左至右标识:0-掩码从左至右;-1-掩码从右至左;其他则按位截取,比如2-从第三位开始截取
* @param subIndex 掩码位数
* @return
* @throws HiveException
*/
public String evaluate(String input,Integer startIndex,Integer subIndex) throws HiveException {
//掩码处理
String append = "";
if (startIndex == MASK_LEFT || startIndex == MASK_RIGHT) {
for (int i = 0;i < subIndex;i++) {
append += "*";
}
} else {
for (int i = 0;i < (subIndex - startIndex);i++) {
append += "*";
}
}
if (startIndex == MASK_LEFT) {
return append + input.substring(subIndex);
} else if (startIndex == MASK_RIGHT) {
return input.substring(0, input.length() - subIndex) + append;
} else {
return input.substring(0,startIndex) + append + input.substring(subIndex);
}
}
//测试
public static void main(String[] args) {
String input = "18866866888";
String append = "";
for (int i = 0;i < (6 - 4);i++) {
append += "*";
}
System.out.println(input.substring(0,4) + append + input.substring(6));
}
}
🍓1.1.3、打包放到hive环境
🍒hive-env.sh配置jar包路径
将jar包放到HIVE_AUX_JARS_PATH
对应的目录下(不再需要单独执行add jar …),重启hive
export HIVE_AUX_JARS_PATH=/root/collect
🍓1.1.4、创建临时函数测试
create temporary function mask_udf as "com.renxiaozhao.udf.MaskUDF";
🍓1.1.5、验证
select mask_udf('18792010988',3,6);
🍊1.2、继承GenericUDF函数
适合处理复杂数据,list、map等,更加灵活,但是实现起来比较复杂,最容易报各种类之间的转换错,需要重写三个方法:
- initialize :初始化方法,可以给定义的List,初始化赋值、转换、校验参数个数等
- evaluate :同UDF,具体的逻辑处理
- getDisplayString:固定输出一段提示,可以展示一个正常的结果值
🍓1.2.1、直接编写CutOffUDF 实现截取函数,其它同UDF步骤
package com.renxiaozhao.udf;
import org.apache.hadoop.hive.ql.exec.UDFArgumentException;
import org.apache.hadoop.hive.ql.metadata.HiveException;
import org.apache.hadoop.hive.ql.udf.generic.GenericUDF;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspectorConverters;
import org.apache.hadoop.hive.serde2.objectinspector.PrimitiveObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorFactory;
/**
* 截断函数.
* @author rxz 20220810
*
*/
public class CutOffUDF extends GenericUDF {
private static final int CUT_LEFT = 0;//截取从左至右标识
private static final int CUT_RIGHT = -1;//截取从右至左标识
ObjectInspectorConverters.Converter[] converters = new ObjectInspectorConverters.Converter[3];
/**
* 初始化操作,在函数进行初始化的时候会执行,其他时间不执行.
*/
public ObjectInspector initialize(ObjectInspector[] arguments) throws UDFArgumentException {
if (arguments.length != 3) {
throw new UDFArgumentException("参数个数不符合要求,应包含三个参数");
}
if (arguments.length == 3) {
//判断: 参数类型
if ((((PrimitiveObjectInspector) arguments[0])).getPrimitiveCategory() != PrimitiveObjectInspector.PrimitiveCategory.STRING) {
throw new UDFArgumentException("第一个参数类型应为String");
}
if ((((PrimitiveObjectInspector) arguments[1])).getPrimitiveCategory() != PrimitiveObjectInspector.PrimitiveCategory.INT) {
throw new UDFArgumentException("第二个参数类型应为Int");
}
if ((((PrimitiveObjectInspector) arguments[2])).getPrimitiveCategory() != PrimitiveObjectInspector.PrimitiveCategory.INT) {
throw new UDFArgumentException("第三个参数类型应为Int");
}
//参数 <--->参数转换器
converters[0] = ObjectInspectorConverters.getConverter(arguments[0], PrimitiveObjectInspectorFactory.javaStringObjectInspector);
converters[1] = ObjectInspectorConverters.getConverter(arguments[1], PrimitiveObjectInspectorFactory.javaIntObjectInspector);
converters[2] = ObjectInspectorConverters.getConverter(arguments[2], PrimitiveObjectInspectorFactory.javaIntObjectInspector);
}
return PrimitiveObjectInspectorFactory.javaStringObjectInspector;
}
/**
* 进行业务计算逻辑,处理具体的数据.
*/
public String evaluate(DeferredObject[] arguments) throws HiveException {
//输入掩码参数
String input = (String)converters[0].convert(arguments[0].get());
//0-掩码从左至右;-1-掩码从右至左
int startIndex = (Integer)converters[1].convert(arguments[1].get());
//掩码位数
int subIndex = (Integer)converters[2].convert(arguments[2].get());
//掩码处理
if (startIndex == CUT_LEFT) {
return input.substring(0, input.length() - subIndex);
} else if (startIndex == CUT_RIGHT) {
return input.substring(subIndex);
} else {
return input.substring(0,startIndex) + input.substring(subIndex);
}
}
/**
* 进行函数描述结果的显示.
*/
public String getDisplayString(String[] children) {
return "cutoffudf('18866866888',0,3) = 66866888";
}
public static void main(String[] args) {
String input = "18866866888";
System.out.println(input.substring(0,4) + input.substring(6));
}
}
🍓1.2.2、测试
create temporary function cutoff_udf as "com.renxiaozhao.udf.CutOffUDF";
select cutoff_udf('18792010988',3,6);
🍑二、JDBC连接测试
🍊2.1、创建表及数据
SQL 语句:
CREATE TABLE `rxz_udf_test`(`phone` varchar(100));
insert into rxz_udf_test(phone) values ('18792010980');
select * from rxz_udf_test;
特别慢…
🍊2.2、创建正式函数
临时函数只针对当前会话,只在该会话内有效
create function rxz_mask as "com.renxiaozhao.udf.MaskUDF";
create function rxz_cutoff as "com.renxiaozhao.udf.CutOffUDF";
🍊2.3、JDBC连接工具类及驱动引入
🍓2.3.1、HiveJDBCUtil
package com.renxiaozhao.udf.util;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**.
* JDBC连接工具类
* @author
*
*/
public class HiveJDBCUtil {
private static final Logger LOGGER = LoggerFactory.getLogger(HiveJDBCUtil.class);
public static Connection getConn() throws ClassNotFoundException {
Connection conn = null;
try {
Class.forName("org.apache.hive.jdbc.HiveDriver");
conn = DriverManager.getConnection("jdbc:hive2://192.168.38.10:10000/default", "root", "");// 连接数据库
} catch (SQLException e) {
LOGGER.error("HiveJDBCUtil.getConn()异常---->", e);
}
return conn;
}
public void closeConn(Connection conn) {
try {
if (conn != null) {
conn.close();
conn = null;
}
} catch (SQLException e) {
LOGGER.error("HiveJDBCUtil.closeConn()异常---->" + e);
}
}
public static PreparedStatement getPStmt(Connection conn, String sql) {
PreparedStatement pstmt = null;
try {
pstmt = conn.prepareStatement(sql);
} catch (SQLException e) {
LOGGER.error("HiveJDBCUtil.getPStmt()异常---->" + e);
}
return pstmt;
}
public static void closePStmt(PreparedStatement stmt) {
try {
if (stmt != null) {
stmt.close();
stmt = null;
}
} catch (SQLException e) {
LOGGER.error("HiveJDBCUtil.closePStmt()异常---->" + e);
}
}
public static void closeRs(ResultSet rs) {
try {
if (rs != null) {
rs.close();
rs = null;
}
} catch (SQLException e) {
LOGGER.error("HiveJDBCUtil.closeRs()异常---->" + e);
}
}
public ResultSet executeQuery(Connection conn, String sql) {
ResultSet rs = null;
try {
rs = conn.createStatement().executeQuery(sql);
} catch (SQLException e) {
LOGGER.error("HiveJDBCUtil.executeQuery()异常---->", e);
}
return rs;
}
}
🍓2.3.2、pom.xml引入hive-jdbc驱动
<dependency>
<groupId>org.apache.hive</groupId>
<artifactId>hive-jdbc</artifactId>
<version>3.1.0</version>
</dependency>
🍊2.4、UDF测试类
🍓2.4.1、UdfUseDemo
package com.renxiaozhao.udf;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import com.renxiaozhao.udf.util.HiveJDBCUtil;
/**
* UdfUseDemo.
* @author
*/
public class UdfUseDemo {
public static void main(String[] args) throws ClassNotFoundException, SQLException {
Connection conn = HiveJDBCUtil.getConn();
//掩码函数rxz_mask
String maskSql1 = "select rxz_mask(phone,0,4) as maskPhone from rxz_udf_test";
String maskSql2 = "select rxz_mask(phone,-1,4) as maskPhone from rxz_udf_test";
String maskSql3 = "select rxz_mask(phone,3,4) as maskPhone from rxz_udf_test";
PreparedStatement maskPstmt1 = HiveJDBCUtil.getPStmt(conn,maskSql1);
PreparedStatement maskPstmt2 = HiveJDBCUtil.getPStmt(conn,maskSql2);
PreparedStatement maskPstmt3 = HiveJDBCUtil.getPStmt(conn,maskSql3);
ResultSet maskRes1 = maskPstmt1.executeQuery();
ResultSet maskRes2 = maskPstmt2.executeQuery();
ResultSet maskRes3 = maskPstmt3.executeQuery();
while (maskRes1.next()) {
System.out.println("掩码 rxz_mask(phone,0,4):" + maskRes1.getString("maskPhone"));
}
while (maskRes2.next()) {
System.out.println("掩码 rxz_mask(phone,-1,4):" + maskRes2.getString("maskPhone"));
}
while (maskRes3.next()) {
System.out.println("掩码 rxz_mask(phone,3,4):" + maskRes3.getString("maskPhone"));
}
HiveJDBCUtil.closePStmt(maskPstmt1);
HiveJDBCUtil.closePStmt(maskPstmt2);
HiveJDBCUtil.closePStmt(maskPstmt3);
HiveJDBCUtil.closeRs(maskRes1);
HiveJDBCUtil.closeRs(maskRes2);
HiveJDBCUtil.closeRs(maskRes3);
//截断函数rxz_cutoff
conn = HiveJDBCUtil.getConn();
String cutoffSql1 = "select rxz_cutoff(phone,0,4) as cutoffPhone from rxz_udf_test";
String cutoffSql2 = "select rxz_cutoff(phone,-1,4) as cutoffPhone from rxz_udf_test";
String cutoffSql3 = "select rxz_cutoff(phone,3,4) as cutoffPhone from rxz_udf_test";
PreparedStatement cutoffPstmt1 = HiveJDBCUtil.getPStmt(conn,cutoffSql1);
PreparedStatement cutoffPstmt2 = HiveJDBCUtil.getPStmt(conn,cutoffSql2);
PreparedStatement cutoffPstmt3 = HiveJDBCUtil.getPStmt(conn,cutoffSql3);
ResultSet cutoffRes1 = cutoffPstmt1.executeQuery();
ResultSet cutoffRes2 = cutoffPstmt2.executeQuery();
ResultSet cutoffRes3 = cutoffPstmt3.executeQuery();
while (cutoffRes1.next()) {
System.out.println("截断 rxz_cutoff(phone,0,4):" + cutoffRes1.getString("cutoffPhone"));
}
while (cutoffRes2.next()) {
System.out.println("截断 rxz_cutoff(phone,-1,4):" + cutoffRes2.getString("cutoffPhone"));
}
while (cutoffRes3.next()) {
System.out.println("截断 rxz_cutoff(phone,3,4):" + cutoffRes3.getString("cutoffPhone"));
}
HiveJDBCUtil.closePStmt(cutoffPstmt1);
HiveJDBCUtil.closePStmt(cutoffPstmt2);
HiveJDBCUtil.closePStmt(cutoffPstmt3);
HiveJDBCUtil.closeRs(cutoffRes1);
HiveJDBCUtil.closeRs(cutoffRes2);
HiveJDBCUtil.closeRs(cutoffRes3);
}
}
🍓2.4.2、测试结果
🍒2.4.2.1、截断函数报错
🍒2.4.2.2、原因-类型不匹配
表定义的varchar
类型,代码写的String
类型,不想打包了,直接修改字段类型,再次验证:
🍇2.4.2.2.1、修改字段类型
alter table rxz_udf_test change column phone phone string;
🍇2.4.2.2.2、再次验证
JDBC验证:
🍑三、其他
- 测试报
Invalid function xxx
,可以同步UDF函数,登录hive执行reload function;
- Concurrency mode is disabled, not creating a lock manager
放开hive-env.sh
的export HADOOP_HEAPSIZE=1024
,默认256,放开后重启依然会报上面提示,不过目前没发现影响。
🍊源码下载
- 源码下载地址包含之前采集hive元数据的代码,需要自取