HBase Java API使用IDEA开发----mapreduce读取hdfs文件写入hbase

一、配置hadoop读取hbase的支持包

    在hadoop-env.sh   添加export HADOOP_CLASSPATH=$HBASE_HOME/lib/*

 没有配置HBASE_HOME的去/etc/profile配置环境变量，路径根据你自己的自行修改

 二、把需要读取的文件上传到hdfs的/user目录下

hdfs dfs  -put /usr/local/software/hadoop/hadoop-3.3.0/stumer_in_out_details.txt   /user/

三、编写代码实现

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
import org.apache.hadoop.hbase.mapreduce.TableMapReduceUtil;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.input.TextInputFormat;


import java.io.IOException;
import java.nio.charset.StandardCharsets;

import java.text.ParseException;
import java.text.SimpleDateFormat;

/**
 * 使用MapReduce读取linux 本地文件写入hbase
 */
public class MapreduceFileToHbase {

    public static void main(String[] args) throws IOException, ClassNotFoundException, InterruptedException {

        String tableName="identify_rmb_records";
        //默认hdfs上的文件，需要提前把文件放上去
        Path inputDir=new Path("/user/stumer_in_out_details.txt");
        Configuration configuration=new Configuration();
        Job job=Job.getInstance(configuration,"mapreduce to hbase");
        job.setJarByClass(MapreduceFileToHbase.class);
        FileInputFormat.setInputPaths(job,inputDir);
        job.setInputFormatClass(TextInputFormat.class);
        job.setMapperClass(ImportMapper.class);
        TableMapReduceUtil.initTableReducerJob(
                tableName,null,job
        );
        job.setNumReduceTasks(0);
        System.exit(job.waitForCompletion(true) ? 0:1);
    }

    public static class ImportMapper extends Mapper<LongWritable, Text, ImmutableBytesWritable, Put> {
        private Put put= null;
        private ImmutableBytesWritable rowkey=new ImmutableBytesWritable();
        SimpleDateFormat format=new SimpleDateFormat("yyyy-MM-dd HH:mm");


        @Override
        protected void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {
            String[] values=value.toString().split(",",-1);
            rowkey.set(Bytes.toBytes(values[0]));
            put=new Put(values[0].getBytes(StandardCharsets.UTF_8));
            long timeStamp=0;

            try {
                timeStamp=format.parse(values[2]).getTime();
            } catch (ParseException e) {
                e.printStackTrace();
            }
            put.addColumn("op_www".getBytes(StandardCharsets.UTF_8),"exists".getBytes(StandardCharsets.UTF_8),timeStamp,values[1].getBytes(StandardCharsets.UTF_8));
            put.addColumn("op_www".getBytes(StandardCharsets.UTF_8),"Bank".getBytes(StandardCharsets.UTF_8),timeStamp,values[3].getBytes(StandardCharsets.UTF_8));
            put.addColumn("op_www".getBytes(StandardCharsets.UTF_8),"uId".getBytes(StandardCharsets.UTF_8),timeStamp,values[4].getBytes(StandardCharsets.UTF_8));
            context.write(rowkey,put);
        }
    }
}

四、使用maven打包项目，上传到linux，执行程序

把jar包文件复制出来传到linu目录下 

在hadoop的bin目录下执行 hadoop jar  jar包名字  类名

./hadoop jar ../wordcount-1.0-SNAPSHOT.jar com.example.usehbase.MapreduceFileToHbase