Spark读写HBase

sc.newAPIHadoopRDD(conf, classOf[TableInputFormat], classOf[ImmutableBytesWritable], classOf[Result])

注：

1. 默认partition个数等于hbase表region个数
2. 可通过重写TableInputFormat的getStartEndKeys方法实现自定义分区

例：

public class CustomTableInputFormat extends TableInputFormat {
    
    public static final String SCAN_SPLIT_NUM = "hbase.mapreduce.scan.split.num";

    @Override
    protected Pair getStartEndKeys() {
        Configuration conf = this.getConf();
        int splitNum = Integer.valueOf(
            conf.get(CrawlTableInputFormat.SCAN_SPLIT_NUM, "1")
        );
        if (splitNum < 1) {
            splitNum = 1;
        }
        byte[][] splits = Bytes.split(
            Bytes.toBytes(conf.get(TableInputFormat.SCAN_ROW_START)),
            Bytes.toBytes(conf.get(TableInputFormat.SCAN_ROW_STOP)),
            true,
            splitNum - 1
        );
        int len = splits.length;
        byte[][] startKeys = new byte[len][];
        byte[][] endKeys = new byte[len][];
        for (int i = 0; i < len - 1; ++i) {
            startKeys[i] = splits[i];
            endKeys[i] = splits[i + 1];
        }
        return new Pair<>(startKeys, endKeys);
    }

}
 
//调用
...
val conf = HBaseConfiguration.create(sc.hadoopConfiguration)
conf.set(CustomTableInputFormat.SCAN_SPLIT_NUM, "100")
sc.newAPIHadoopRDD(conf, classOf[CustomTableInputFormat], classOf[ImmutableBytesWritable], classOf[Result]) 
...