hbase如何编写mapreduce

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package com.hbase.test;import java.io.IOException;import org.apache.hadoop.conf.Configuration;import org.apache.hadoop.hbase.HBaseConfiguration;import org.apache.hadoop.hbase.client.Mutation;import org.apache.hadoop.hbase.client.Put;import org.apache.hadoop.hbase.client.Result;import org.apache.hadoop.hbase.client.Scan;import org.apache.hadoop.hbase.io.ImmutableBytesWritable;import org.apache.hadoop.hbase.mapreduce.TableMapReduceUtil;import org.apache.hadoop.hbase.mapreduce.TableMapper;import org.apache.hadoop.hbase.mapreduce.TableReducer;import org.apache.hadoop.hbase.util.Bytes;import org.apache.hadoop.io.IntWritable;import org.apache.hadoop.io.Text;import org.apache.hadoop.mapreduce.Job;import org.apache.hadoop.mapreduce.Mapper;import org.apache.hadoop.mapreduce.Reducer;public class HbaseMrTest {        public static void main(String[] args) throws IOException, ClassNotFoundException, InterruptedException {                Configuration conf =  HBaseConfiguration.create();                //配置conf                conf.set("hbase.zookeeper.quorum", "bigdata01,bigdata02,bigdata03");                conf.set("hbase.zookeeper.property.clientPort", "2181");                       Job job = Job.getInstance(conf, "word-count");                //指定执行job的主类                job.setJarByClass(HbaseMrTest.class);                Scan scan = new Scan();                //定义mapper需要扫描的列                scan.addColumn(Bytes.toBytes("content"), Bytes.toBytes("words"));                //配置mapper                TableMapReduceUtil.initTableMapperJob("wordcount", scan,HMapper.class , Text.class, IntWritable.class, job);                //配置recuder                TableMapReduceUtil.initTableReducerJob("result", HReducer.class, job);                //提交job                System.exit(job.waitForCompletion(true)?0:1);        }}// Text, IntWritable 为输出类型class HMapper extends TableMapper{        Text out = new Text();        IntWritable iw = new IntWritable(1);        @Override        protected void map(ImmutableBytesWritable key, Result value,                        Mapper.Context context)                        throws IOException, InterruptedException {                //通过result 直接过得content:words 的值                byte[] bytes =  value.getValue(Bytes.toBytes("content"), Bytes.toBytes("words"));                if(bytes!=null) {                        String words = Bytes.toString(bytes);                        //对获得的一行单词进行分割                        String[] ws = words.split(" ");                        for(String wd : ws) {                                out.set(wd);                                //写出值，如: you 1                                context.write(out, iw);                        }                                       }        }       }// Text, IntWritable 为mapper的输出类型class HReducer extends TableReducer{        @Override        protected void reduce(Text text, Iterable iter,                        Reducer.Context context)                        throws IOException, InterruptedException {                int sum = 0 ;                //对iter遍历                for(IntWritable intw : iter) {                        sum+= intw.get();                }                //new 一个put 构造函数内的值为row key                Put put = new Put(Bytes.toBytes(text.toString()));                //put添加columnfamily 和column                put.addColumn(Bytes.toBytes("info"), Bytes.toBytes("wordcnt"), Bytes.toBytes(String.valueOf(sum)));                //将每个单词当做row key 写出，put是相加的总和                context.write(new ImmutableBytesWritable(Bytes.toBytes(text.toString())), put);        }        }最后将java文件export为RaunableJar放到linux java -jar hbase.jar com.hbase.test.HbaseMrTest 运行

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