将HDFS中的信息读入到Hbase

要将HDFS中的信息读入到HBase，可以使用HBase提供的工具类，如TableMapReduceUtil和HFileOutputFormat2等。下面是一个简单的示例：

1. 创建一个MapReduce程序，并在mapper中读取HDFS中的文件，将数据写入到HBase中：

public class HDFS2HBaseMapper extends Mapper<LongWritable, Text, ImmutableBytesWritable, Put> {
    private final static byte[] CF = "cf".getBytes();
    private final static byte[] ATTR1 = "attr1".getBytes();
    private final static byte[] ATTR2 = "attr2".getBytes();

    public void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {
        String[] fields = value.toString().split(",");
        String rowKey = fields[0];
        Put put = new Put(rowKey.getBytes());
        put.addColumn(CF, ATTR1, fields[1].getBytes());
        put.addColumn(CF, ATTR2, fields[2].getBytes());
        context.write(new ImmutableBytesWritable(rowKey.getBytes()), put);
    }
}

2. 在Driver中配置HBase表和HDFS输入路径，并设置HFileOutputFormat2的输出路径：

public class HDFS2HBaseDriver {
    public static void main(String[] args) throws Exception {
        Configuration conf = HBaseConfiguration.create();
        conf.set("hbase.zookeeper.quorum", "localhost");
        conf.set("hbase.zookeeper.property.clientPort", "2181");
        conf.set(TableOutputFormat.OUTPUT_TABLE, "mytable");

        Job job = Job.getInstance(conf, "HDFS2HBase");
        job.setJarByClass(HDFS2HBaseDriver.class);
        job.setMapperClass(HDFS2HBaseMapper.class);
        job.setOutputFormatClass(HFileOutputFormat2.class);
        job.setMapOutputKeyClass(ImmutableBytesWritable.class);
        job.setMapOutputValueClass(Put.class);

        FileInputFormat.setInputPaths(job, new Path("/input"));
        FileOutputFormat.setOutputPath(job, new Path("/output"));
        HFileOutputFormat2.configureIncrementalLoad(job, new HTable(conf, "mytable"));
        System.exit(job.waitForCompletion(true) ? 0 : 1);
    }
}

3. 运行MapReduce程序，并将输出的HFile文件导入到HBase中：

$ hbase org.apache.hadoop.hbase.mapreduce.LoadIncrementalHFiles /hbase/output mytable

以上就是将HDFS中的信息读入到HBase的基本步骤，具体可根据实际需求进行调整。