HBASE11
4.3.3 自定义 Hbase-MapReduce2
目标：实现将 HDFS 中的数据写入到 Hbase 表中。
分步实现：
1．构建 ReadFruitFromHDFSMapper 于读取 HDFS 中的文件数据
package com.atguigu;
import java.io.IOException;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Mapper;
public class ReadFruitFromHDFSMapper extends Mapper<LongWritable,
Text, ImmutableBytesWritable, Put> {
@Override
protected void map(LongWritable key, Text value, Context
context) throws IOException, InterruptedException {
//从 HDFS 中读取的数据
String lineValue = value.toString();
//读取出来的每行数据使用\t 进行分割，存于 String 数组
String[] values = lineValue.split("\t");
//根据数据中值的含义取值
String rowKey = values[0];
String name = values[1];
String color = values[2];
//初始化 rowKey
ImmutableBytesWritable rowKeyWritable = new
ImmutableBytesWritable(Bytes.toBytes(rowKey));
//初始化 put 对象
Put put = new Put(Bytes.toBytes(rowKey));
//参数分别:列族、列、值
put.add(Bytes.toBytes("info"), Bytes.toBytes("name"),
Bytes.toBytes(name));
put.add(Bytes.toBytes("info"), Bytes.toBytes("color"),
Bytes.toBytes(color));
context.write(rowKeyWritable, put);
}
}
2．构建 WriteFruitMRFromTxtReducer 类
package com.z.Hbase.mr2;
import java.io.IOException;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
import org.apache.hadoop.hbase.mapreduce.TableReducer;
import org.apache.hadoop.io.NullWritable;
public class WriteFruitMRFromTxtReducer extends
TableReducer<ImmutableBytesWritable, Put, NullWritable> {
@Override
protected void reduce(ImmutableBytesWritable key, Iterable<Put>
values, Context context) throws IOException, InterruptedException
{
//读出来的每一行数据写入到 fruit_hdfs 表中
for(Put put: values){
context.write(NullWritable.get(), put);
}
}
}
3．创建 Txt2FruitRunner 组装 Job
public int run(String[] args) throws Exception {
//得到 Configuration
Configuration conf = this.getConf();
//创建 Job 任务
Job job = Job.getInstance(conf, this.getClass().getSimpleName());
job.setJarByClass(Txt2FruitRunner.class);
Path inPath = new
Path("hdfs://hadoop102:9000/input_fruit/fruit.tsv");
FileInputFormat.addInputPath(job, inPath);
//设置 Mapper
job.setMapperClass(ReadFruitFromHDFSMapper.class);
job.setMapOutputKeyClass(ImmutableBytesWritable.class);
job.setMapOutputValueClass(Put.class);
//设置 Reducer
TableMapReduceUtil.initTableReducerJob("fruit_mr",
WriteFruitMRFromTxtReducer.class, job);
//设置 Reduce 数量，最少 1 个
job.setNumReduceTasks(1);
boolean isSuccess = job.waitForCompletion(true);
if(!isSuccess){
throw new IOException("Job running with error");
}
return isSuccess ? 0 : 1;
}
4．调用执行 Job
public static void main(String[] args) throws Exception {
Configuration conf = HBaseConfiguration.create();
int status = ToolRunner.run(conf, new Txt2FruitRunner(),
args);
System.exit(status);
}
5．打包运行
$ /opt/module/hadoop-2.7.2/bin/yarn jar hbase-0.0.1-SNAPSHOT.jar
com.atguigu.hbase.mr2.Txt2FruitRunner
