一、UDF函数编写

1.步骤

1.继承UDF类

2.重写evalute方法
1、继承GenericUDF

2、实现initialize、evaluate、getDisplayString方法

2.案例

实现lower函数:

package com.xxx.udf;

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

import org.apache.hadoop.io.Text;

public class LowerUDF extends UDF {

    public Text evaluate(Text input){

        if(null == input){

            return null;

        }

        String inputValue = input.toString().trim() ;

        if(null == inputValue){

            return null ;

        }

        return new Text(inputValue.toLowerCase()) ;

    }

}
package com.xxx.udf;

import org.apache.hadoop.hive.ql.exec.UDFArgumentException;

import org.apache.hadoop.hive.ql.exec.UDFArgumentLengthException;

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.primitive.PrimitiveObjectInspectorFactory;

import org.apache.hadoop.hive.serde2.objectinspector.primitive.StringObjectInspector;

import org.apache.hadoop.io.Text;

public class LowerUDF extends GenericUDF {

    StringObjectInspector str ;

    @Override

    public ObjectInspector initialize(ObjectInspector[] arguments) throws UDFArgumentException {

        //判断输入参数个数是否合法

        if (arguments.length != 1) {

            throw new UDFArgumentLengthException("输入参数长度不合法,应该为一个参数");

        }

        //判断输入参数类型是否合法

        if (!(arguments[0] instanceof StringObjectInspector)) {

            throw new UDFArgumentException("输入非法参数，应为字符串类型");

        }

        str=(StringObjectInspector)arguments[0];

        //确定返回值类型

        return PrimitiveObjectInspectorFactory.javaStringObjectInspector;

    }

    @Override

    public Object  evaluate(DeferredObject[] arguments) throws HiveException {

        String input = str.getPrimitiveJavaObject(arguments[0].get());

        return new Text(input.toLowerCase());

    }

    @Override

    public String getDisplayString(String[] children) {

        return "方法的描述信息";

    }

}

3.打成jar包上传

mvn clean package

4.在hive中创建临时函数

add jar /home/xxx/yf/to_lower.jar;

create temporary function to_lower as 'com.xxx.udf.LowerUDF';

select to_lower("DSJIFASD") from dual;

drop temporary function comparestringbysplit;

二、UDAF函数编写

1.步骤

1、继承AbstractGenericUDAFResolver

2、继承GenericUDAFEvaluator

3、Evaluator需要实现 init、iterate、terminatePartial、merge、terminate这几个函数

   init初始化

   iterate函数处理读入的行数据

   terminatePartial返回iterate处理的中间结果

   merge合并上述处理结果

   terminate返回最终值

2.案例

实现avg

package com.xxx.udf;

import org.apache.hadoop.hive.ql.exec.UDAF;

import org.apache.hadoop.hive.ql.exec.UDAFEvaluator;

public class Avg extends UDAF {

    public static class AvgState {

        private long mCount;

        private double mSum;

    }

    public static class AvgEvaluator implements UDAFEvaluator {

        AvgState state;

        public AvgEvaluator() {

            super();

            state = new AvgState();

            init();

        }

        /**

         * init函数类似于构造函数，用于UDAF的初始化

         */

        public void init() {

            state.mSum = 0;

            state.mCount = 0;

        }

        /**

         * iterate接收传入的参数，并进行内部的轮转。其返回类型为boolean * * @param o * @return

         */

        public boolean iterate(Double o) {

            if (o != null) {

                state.mSum += o;

                state.mCount++;

            }

            return true;

        }

        /**

         * terminatePartial无参数，其为iterate函数遍历结束后，返回轮转数据， * terminatePartial类似于hadoop的Combiner * * @return

         */

        public AvgState terminatePartial() {

            // combiner

            return state.mCount == 0 ? null : state;

        }

        /**

         * merge接收terminatePartial的返回结果，进行数据merge操作，其返回类型为boolean * * @param o * @return

         */

        public boolean merge(AvgState avgState) {

            if (avgState != null) {

                state.mCount += avgState.mCount;

                state.mSum += avgState.mSum;

            }

            return true;

        }

        /**

         * terminate返回最终的聚集函数结果 * * @return

         */

        public Double terminate() {

            return state.mCount == 0 ? null : Double.valueOf(state.mSum / state.mCount);

        }

    }

}

实现sum

package com.xxx.udf;

import org.apache.hadoop.hive.ql.exec.UDFArgumentException;

import org.apache.hadoop.hive.ql.exec.UDFArgumentLengthException;

import org.apache.hadoop.hive.ql.metadata.HiveException;

import org.apache.hadoop.hive.ql.parse.SemanticException;

import org.apache.hadoop.hive.ql.udf.generic.AbstractGenericUDAFResolver;

import org.apache.hadoop.hive.ql.udf.generic.GenericUDAFEvaluator;

import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;

import org.apache.hadoop.hive.serde2.objectinspector.PrimitiveObjectInspector;

import org.apache.hadoop.hive.serde2.objectinspector.primitive.DoubleObjectInspector;

import org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorFactory;

import org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorUtils;

import org.apache.hadoop.hive.serde2.objectinspector.primitive.StringObjectInspector;

import org.apache.hadoop.hive.serde2.typeinfo.TypeInfo;

import org.apache.hadoop.io.DoubleWritable;

import org.apache.hadoop.io.LongWritable;

public class Test extends AbstractGenericUDAFResolver {

    /**

     * 获取处理逻辑类

     * @param info

     * @return

     * @throws SemanticException

     */

    @Override

    public GenericUDAFEvaluator getEvaluator(TypeInfo[] info) throws SemanticException {

        //判断输入参数是否合法,参数个数，参数类型

        if (info.length != 1) {

            throw new UDFArgumentLengthException("输入参数个数非法，一个参数");

        }

        return new GenericEvaluate();

    }

    //处理逻辑类

    public static class GenericEvaluate extends GenericUDAFEvaluator {

        private PrimitiveObjectInspector input;

        private DoubleWritable result ;                   //保存最终结果

        private MyAggregationBuffer myAggregationBuffer;  //自定义聚合列，保存临时结果

        //自定义AggregationBuffer

        public static class MyAggregationBuffer implements AggregationBuffer {

            Double sum;

        }

        @Override  //指定返回类型

        public ObjectInspector init(Mode m, ObjectInspector[] parameters) throws HiveException {

            super.init(m, parameters);

            result = new DoubleWritable(0);

            input = (PrimitiveObjectInspector) parameters[];

            // 指定返回结果类型

            return PrimitiveObjectInspectorFactory.writableDoubleObjectInspector;

        }

        @Override   //获得一个聚合的缓冲对象，每个map执行一次

        public AggregationBuffer getNewAggregationBuffer() throws HiveException {

            MyAggregationBuffer myAggregationBuffer = new MyAggregationBuffer();

            reset(myAggregationBuffer);  // 重置聚合值

            return myAggregationBuffer;

        }

        @Override

        public void reset(AggregationBuffer agg) throws HiveException {

            MyAggregationBuffer newAgg = (MyAggregationBuffer) agg;

            newAgg.sum = 0.0;

        }

        @Override  // 传入参数值聚合

        public void iterate(AggregationBuffer agg, Object[] parameters) throws HiveException {

            MyAggregationBuffer myAgg = (MyAggregationBuffer) agg;

            double inputNum = PrimitiveObjectInspectorUtils.getDouble(parameters[], input);

            myAgg.sum += inputNum;

        }

        @Override  //

        public Object terminatePartial(AggregationBuffer agg) throws HiveException {

            MyAggregationBuffer newAgg = (MyAggregationBuffer) agg;

            result.set(newAgg.sum);

            return result;

        }

        @Override  // 合并

        public void merge(AggregationBuffer agg, Object partial) throws HiveException {

            double inputNum = PrimitiveObjectInspectorUtils.getDouble(partial, input);

            MyAggregationBuffer newAgg = (MyAggregationBuffer) agg;

            newAgg.sum += inputNum;

        }

        @Override  //输出最终结果

        public Object terminate(AggregationBuffer agg) throws HiveException {

            MyAggregationBuffer aggregationBuffer = (MyAggregationBuffer) agg;

            result.set(aggregationBuffer.sum);

            return result;

        }

    }

}

3.打包

mvn clean package

4.创建临时函数

add jar /home/xxx/yf/my_avg.jar;

create temporary function my_avg as 'com.xxx.udf.UDTFExplode';

select my_avg() from dual;

drop temporary function my_avg;

三、UDTF函数编写

1.步骤

1.继承GenericUDTF

2.重写initialize、process方法

  initialize初始化校验参数是否正确、

  process处理返回结果、

  forward将结果返回

2.案例

将字符串按照元素索引分别输出，如：‘a,c,b’   -- > a,1    c,2  b,3

package com.suning.udf;

import java.util.ArrayList;

import org.apache.hadoop.hive.ql.exec.UDFArgumentException;

import org.apache.hadoop.hive.ql.exec.UDFArgumentLengthException;

import org.apache.hadoop.hive.ql.metadata.HiveException;

import org.apache.hadoop.hive.ql.udf.generic.GenericUDTF;

import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;

import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspectorFactory;

import org.apache.hadoop.hive.serde2.objectinspector.StructObjectInspector;

import org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorFactory;

public class UDTFExplode extends GenericUDTF {

    @Override

    public void close() throws HiveException {

        // TODO Auto-generated method stub

    }

    @Override

    public StructObjectInspector initialize(ObjectInspector[] args) throws UDFArgumentException {

        if (args.length != 1) {

            throw new UDFArgumentLengthException("ExplodeMap takes only one argument");

        }

        if (args[].getCategory() != ObjectInspector.Category.PRIMITIVE) {

            throw new UDFArgumentException("ExplodeMap takes string as a parameter");

        }

        ArrayList<String> fieldNames = new ArrayList<String>();

        ArrayList<ObjectInspector> fieldOIs = new ArrayList<ObjectInspector>();

        fieldNames.add("col1");

        fieldOIs.add(PrimitiveObjectInspectorFactory.javaStringObjectInspector);

        fieldNames.add("col2");

        fieldOIs.add(PrimitiveObjectInspectorFactory.javaStringObjectInspector);

        return ObjectInspectorFactory.getStandardStructObjectInspector(fieldNames, fieldOIs);

    }

    @Override

    public void process(Object[] args) throws HiveException {

        // TODO Auto-generated method stub

        String input = args[].toString();

        String[] test = input.split(",");

        for (int i = 0; i < test.length; i++) {

            try {

                String[] result = (test[i]+":"+String.valueOf(i+1)).split(":");

                forward(result);

            } catch (Exception e) {

                continue;

            }

        }

    }

}

3.打包

mvn clean package

4.创建临时函数

add jar /home/xxx/yf/str_index.jar;

create temporary function str_index as 'com.xxx.udf.UDTFExplode';

select str_index("a,c,b") from dual;

drop temporary function str_index;

pom.xml

<?xml version="1.0" encoding="UTF-8"?>

<project xmlns="http://maven.apache.org/POM/4.0.0"

         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">

    <modelVersion>4.0.0</modelVersion>

    <groupId>spark-hive</groupId>

    <artifactId>spark-hive</artifactId>

    <version>1.0-SNAPSHOT</version>

    <properties>

        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>

        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>

        <scala.version>2.11.8</scala.version>

        <spark.version>2.1.0.9</spark.version>

        <spark.artifactId.version>2.11</spark.artifactId.version>

    </properties>

    <dependencies>

        <dependency>

            <groupId>commons-logging</groupId>

            <artifactId>commons-logging</artifactId>

            <version>1.1.1</version>

            <type>jar</type>

        </dependency>

        <dependency>

            <groupId>org.apache.commons</groupId>

            <artifactId>commons-lang3</artifactId>

            <version>3.1</version>

        </dependency>

        <dependency>

            <groupId>log4j</groupId>

            <artifactId>log4j</artifactId>

            <version>1.2.17</version>

        </dependency>

        <dependency>

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

            <artifactId>hadoop-common</artifactId>

            <version>2.6.2</version>

        </dependency>

        <dependency>

            <groupId>mysql</groupId>

            <artifactId>mysql-connector-java</artifactId>

            <version>5.1.21</version>

        </dependency>

        <dependency>

            <groupId>org.apache.spark</groupId>

            <artifactId>spark-core_2.11</artifactId>

            <version>2.1.0</version>

        </dependency>

        <dependency>

            <groupId>org.apache.spark</groupId>

            <artifactId>spark-streaming_2.11</artifactId>

            <version>2.1.0</version>

        </dependency>

        <dependency>

            <groupId>org.apache.spark</groupId>

            <artifactId>spark-streaming-kafka-0-8_2.11</artifactId>

            <version>2.1.0</version>

        </dependency>

        <dependency>

            <groupId>com.google.code.gson</groupId>

            <artifactId>gson</artifactId>

            <version>2.8.2</version>

        </dependency>

        <dependency>

            <groupId>org.apache.spark</groupId>

            <artifactId>spark-sql_2.11</artifactId>

            <version>2.1.0</version>

        </dependency>

        <dependency>

            <groupId>com.alibaba</groupId>

            <artifactId>fastjson</artifactId>

            <version>1.2.29</version>

        </dependency>

        <dependency>

            <groupId>org.apache.spark</groupId>

            <artifactId>spark-hive_${spark.artifactId.version}</artifactId>

            <version>${spark.version}</version>

            <scope>provided</scope>

        </dependency>

        <!--flink dependency-->

        <dependency>

            <groupId>org.apache.flink</groupId>

            <artifactId>flink-java</artifactId>

            <version>1.5.0</version>

        </dependency>

        <dependency>

            <groupId>org.apache.flink</groupId>

            <artifactId>flink-streaming-java_2.11</artifactId>

            <version>1.5.0</version>

        </dependency>

        <dependency>

            <groupId>org.apache.flink</groupId>

            <artifactId>flink-clients_2.11</artifactId>

            <version>1.5.0</version>

        </dependency>

        <dependency>

            <groupId>org.apache.flink</groupId>

            <artifactId>flink-connector-wikiedits_2.11</artifactId>

            <version>1.5.0</version>

        </dependency>

        <!--hbase dependency-->

        <dependency>

            <groupId>org.apache.hbase</groupId>

            <artifactId>hbase</artifactId>

            <version>0.98.8-hadoop2</version>

            <type>pom</type>

        </dependency>

        <dependency>

            <groupId>org.apache.hbase</groupId>

            <artifactId>hbase-client</artifactId>

            <version>0.98.8-hadoop2</version>

        </dependency>

        <dependency>

            <groupId>org.apache.hbase</groupId>

            <artifactId>hbase-common</artifactId>

            <version>0.98.8-hadoop2</version>

        </dependency>

        <dependency>

            <groupId>org.apache.hbase</groupId>

            <artifactId>hbase-server</artifactId>

            <version>0.98.8-hadoop2</version>

        </dependency>

    </dependencies>

    <build>

        <plugins>

            <plugin>

                <artifactId>maven-assembly-plugin</artifactId>

                <configuration>

                    <descriptorRefs>

                        <descriptorRef>jar-with-dependencies</descriptorRef>

                    </descriptorRefs>

                </configuration>

            </plugin>

            <plugin>

                <groupId>org.codehaus.mojo</groupId>

                <artifactId>build-helper-maven-plugin</artifactId>

                <version>1.8</version>

                <executions>

                    <execution>

                        <id>add-source</id>

                        <phase>generate-sources</phase>

                        <goals>

                            <goal>add-source</goal>

                        </goals>

                        <configuration>

                            <sources>

                                <source>src/main/scala</source>

                                <source>src/test/scala</source>

                            </sources>

                        </configuration>

                    </execution>

                    <execution>

                        <id>add-test-source</id>

                        <phase>generate-sources</phase>

                        <goals>

                            <goal>add-test-source</goal>

                        </goals>

                        <configuration>

                            <sources>

                                <source>src/test/scala</source>

                            </sources>

                        </configuration>

                    </execution>

                </executions>

            </plugin>

            <plugin>

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

                <artifactId>maven-compiler-plugin</artifactId>

                <version>2.3.2</version>

                <configuration>

                    <source>1.7</source>

                    <target>1.7</target>

                    <encoding>${project.build.sourceEncoding}</encoding>

                </configuration>

            </plugin>

            <plugin>

                <groupId>org.scala-tools</groupId>

                <artifactId>maven-scala-plugin</artifactId>

                <executions>

                    <execution>

                        <goals>

                            <goal>compile</goal>

                            <goal>add-source</goal>

                            <goal>testCompile</goal>

                        </goals>

                    </execution>

                </executions>

                <configuration>

                    <scalaVersion>2.11.8</scalaVersion>

                    <sourceDir>src/main/scala</sourceDir>

                    <jvmArgs>

                        <jvmArg>-Xms64m</jvmArg>

                        <jvmArg>-Xmx1024m</jvmArg>

                    </jvmArgs>

                </configuration>

            </plugin>

            <plugin>

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

                <artifactId>maven-release-plugin</artifactId>

                <version>2.5.3</version>

            </plugin>

            <plugin>

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

                <artifactId>maven-deploy-plugin</artifactId>

                <configuration>

                    <skip>false</skip>

                </configuration>

            </plugin>

            <plugin>

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

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

                <version>2.4.1</version>

                <executions>

                    <execution>

                        <phase>package</phase>

                        <goals>

                            <goal>shade</goal>

                        </goals>

                        <configuration>

                            <filters>

                                <filter>

                                    <artifact>*:*</artifact>

                                    <excludes>

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

                                        org.apache.hive                          <exclude>META-INF/*.DSA</exclude>

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

                                    </excludes>

                                </filter>

                            </filters>

                            <minimizeJar>false</minimizeJar>

                        </configuration>

                    </execution>

                </executions>

            </plugin>

        </plugins>

        <resources>

            <resource>

                <directory>src/main/resources</directory>

                <filtering>true</filtering>

            </resource>

            <resource>

                <directory>src/main/resources/${profiles.active}</directory>

            </resource>

        </resources>

        <!-- 修复 Plugin execution not covered by lifecycle configuration -->

        <pluginManagement>

            <plugins>

                <plugin>

                    <groupId>org.eclipse.m2e</groupId>

                    <artifactId>lifecycle-mapping</artifactId>

                    <version>1.0.0</version>

                    <configuration>

                        <lifecycleMappingMetadata>

                            <pluginExecutions>

                                <pluginExecution>

                                    <pluginExecutionFilter>

                                        <groupId>org.codehaus.mojo</groupId>

                                        <artifactId>build-helper-maven-plugin</artifactId>

                                        <versionRange>[1.8,)</versionRange>

                                        <goals>

                                            <goal>add-source</goal>

                                            <goal>add-test-source</goal>

                                        </goals>

                                    </pluginExecutionFilter>

                                    <action>

                                        <ignore></ignore>

                                    </action>

                                </pluginExecution>

                                <pluginExecution>

                                    <pluginExecutionFilter>

                                        <groupId>org.scala-tools</groupId>

                                        <artifactId>maven-scala-plugin</artifactId>

                                        <versionRange>[1.8,)</versionRange>

                                        <goals>

                                            <goal>compile</goal>

                                            <goal>add-source</goal>

                                            <goal>testCompile</goal>

                                        </goals>

                                    </pluginExecutionFilter>

                                    <action>

                                        <ignore></ignore>

                                    </action>

                                </pluginExecution>

                            </pluginExecutions>

                        </lifecycleMappingMetadata>

                    </configuration>

                </plugin>

            </plugins>

        </pluginManagement>

    </build>

</project>

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