阿里音乐流行趋势预测大赛之数加平台OPEN

阿里音乐流行趋势预测大赛之数加平台OPEN"/>

阿里音乐流行趋势预测大赛之数加平台OPEN

写在开头：OPEN_MR在数加平台上可用，ODPS_MR我还没跑出结果，先给大家演示一下OPEN_MR的简单使用。

首先，建立一个Hadoop项目，可以使用御膳房的文档搭建环境(目的使代码能够编译通过)，后面附一份我的御膳房项目(配置maven后可直接导入eclipse使用)。

使用御膳房的文档搭建环境

.html?spm=0.0.0.0.LBzMEE&file=MrUdfLocalDev

下载源码

附上示例代码：

package hadoop.TianChiMapreduce;import java.io.IOException;
import java.util.Iterator;import com.aliyun.odps.data.Record;
import com.aliyun.odps.data.TableInfo;
import com.aliyun.odps.mapred.JobClient;
import com.aliyun.odps.mapred.MapperBase;
import com.aliyun.odps.mapred.ReducerBase;
import com.aliyun.odps.mapred.TaskContext;
import com.aliyun.odps.mapred.conf.JobConf;
import com.aliyun.odps.mapred.utils.InputUtils;
import com.aliyun.odps.mapred.utils.OutputUtils;
import com.aliyun.odps.mapred.utils.SchemaUtils;public class WordCount {public static class TokenizerMapper extends MapperBase {private Record word;private Record one;@Overridepublic void setup(TaskContext context) throws IOException {word = context.createMapOutputKeyRecord();one = context.createMapOutputValueRecord();one.set(new Object[] { 1L });System.out.println("TaskID:" + context.getTaskID().toString());}@Overridepublic void map(long recordNum, Record record, TaskContext context)throws IOException {for (int i = 0; i < record.getColumnCount(); i++) {word.set(new Object[] { record.get(0).toString() });context.write(word, one);}}}/*** A combiner class that combines map output by sum them.**/public static class SumCombiner extends ReducerBase {private Record count;@Overridepublic void setup(TaskContext context) throws IOException {count = context.createMapOutputValueRecord();}@Overridepublic void reduce(Record key, Iterator<Record> values, TaskContext context)throws IOException {long c = 0;while (values.hasNext()) {Record val = values.next();c += (Long) val.get(0);}count.set(0, c);context.write(key, count);}}/*** A reducer class that just emits the sum of the input values.**/public static class SumReducer extends ReducerBase {private Record result = null;@Overridepublic void setup(TaskContext context) throws IOException {result = context.createOutputRecord();}@Overridepublic void reduce(Record key, Iterator<Record> values, TaskContext context)throws IOException {long count = 0;while (values.hasNext()) {Record val = values.next();count += (Long) val.get(0);}result.set(0, key.get(0));result.set(1, count);context.write(result);}}public static void main(String[] args) throws Exception {if (args.length != 2) {System.err.println("Usage: WordCount <in_table> <out_table>");System.exit(2);}JobConf job = new JobConf();job.setMapperClass(TokenizerMapper.class);job.setCombinerClass(SumCombiner.class);job.setReducerClass(SumReducer.class);job.setMapOutputKeySchema(SchemaUtils.fromString("word:string"));job.setMapOutputValueSchema(SchemaUtils.fromString("count:bigint"));InputUtils.addTable(TableInfo.builder().tableName(args[0]).build(), job);OutputUtils.addTable(TableInfo.builder().tableName(args[1]).build(), job);JobClient.runJob(job);}}

项目结构如下：

留一个标红的代码就行，其他没用。

点击WordCount.java右键export导出Jar

打开数加平台点击上传资源

拖动OPEN_MR组件到右侧空白

、

双击组件-按如下填写，前两个是你需要运行的jar，mapper和reducer是你要运行的map类和reudce类，输出表要提前创建好，key和value对应输出表的字段

建表sql：create table if not  exists wcout1 (key string,cnt bigint);

保存运行即可

wcout1的表结构和结果