项目实战 从 0 到 1 学习之Flink （21）Flink读HBase并写入HBase

这里读HBase提供两种方式，一种是继承RichSourceFunction，重写父类方法，一种是实现OutputFormat接口，具体代码如下：

方式一：继承RichSourceFunction

package com.my.flink.utils.streaming.hbase;
 
import com.my.flink.utils.config.ConfigKeys;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.configuration.Configuration;
import org.apache.flink.streaming.api.functions.source.RichSourceFunction;
import org.apache.hadoop.hbase.Cell;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.*;
import org.apache.hadoop.hbase.util.Bytes;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
 
import java.io.IOException;
import java.util.Iterator;
 
/**
 * @Description hbase reader
 * @Author jiangxiaozhi
 * @Date 2018/10/17 10:05
 **/
public class HBaseReader extends RichSourceFunction<Tuple2<String, String>> {
    private static final Logger logger = LoggerFactory.getLogger(HBaseReader.class);
 
    private Connection conn = null;
    private Table table = null;
    private Scan scan = null;
 
    @Override
    public void open(Configuration parameters) throws Exception {
        super.open(parameters);
        conn = HBaseConnection.getHBaseConn();
        table = conn.getTable(TableName.valueOf(ConfigKeys.HBASE_SOURCE_TABLE()));
        scan = new Scan();
        scan.setStartRow(Bytes.toBytes("1001"));
        scan.setStopRow(Bytes.toBytes("1004"));
        scan.addFamily(Bytes.toBytes(ConfigKeys.HBASE_SOURCE_CF()));
 
    }
 
    @Override
    public void run(SourceContext<Tuple2<String, String>> ctx) throws Exception {
        ResultScanner rs = table.getScanner(scan);
        Iterator<Result> iterator = rs.iterator();
        while (iterator.hasNext()) {
            Result result = iterator.next();
            String rowkey = Bytes.toString(result.getRow());
            StringBuffer sb = new StringBuffer();
            for (Cell cell : result.listCells()) {
                String value = Bytes.toString(cell.getValueArray(), cell.getValueOffset(), cell.getValueLength());
                sb.append(value).append(",");
            }
            String valueString = sb.replace(sb.length() - 1, sb.length(), "").toString();
            Tuple2<String, String> tuple2 = new Tuple2<>();
            tuple2.setFields(rowkey, valueString);
            ctx.collect(tuple2);
        }
 
    }
 
    @Override
    public void cancel() {
        try {
            if (table != null) {
                table.close();
            }
            if (conn != null) {
                conn.close();
            }
        } catch (IOException e) {
            logger.error("Close HBase Exception:", e.toString());
        }
 
    }
}

方式二：重写TableInputFormat方法

    env.createInput(new TableInputFormat[org.apache.flink.api.java.tuple.Tuple2[String, String]] {
      override def mapResultToTuple(r: Result): org.apache.flink.api.java.tuple.Tuple2[String, String] = {
        val rowkey = Bytes.toString(r.getRow)
        val sb = new StringBuffer()
        for (cell: Cell <- r.rawCells()) {
          val value = Bytes.toString(cell.getValueArray, cell.getValueOffset, cell.getValueLength)
          sb.append(value).append(",")
        }
        val valueString = sb.replace(sb.length() - 1, sb.length(), "").toString
        val tuple2 = new org.apache.flink.api.java.tuple.Tuple2[String, String]
        tuple2.setField(rowkey, 0)
        tuple2.setField(valueString, 1)
        tuple2
      }
 
      override def getTableName: String = HBASE_SOURCE_TABLE
 
      override def getScanner: Scan = {
        scan
      }
 
      override def configure(parameters: Configuration): Unit = {
        val conf = HBaseConfiguration.create();
        conf.set(HConstants.ZOOKEEPER_QUORUM, ZOOKEEPER_QUORUM)
        conf.set(HConstants.ZOOKEEPER_CLIENT_PORT, ZOOKEEPER_CLIENT_PORT)
        conn = ConnectionFactory.createConnection(conf)
        table = classOf[HTable].cast(conn.getTable(TableName.valueOf(HBASE_SOURCE_TABLE)))
        scan = new Scan() {
          setStartRow(Bytes.toBytes("1001"))
          setStopRow(Bytes.toBytes("1004"))
          addFamily(Bytes.toBytes(HBASE_SOURCE_CF))
        }
      }
 
      override def close() = {
        if (table != null) {
          table.close()
        }
        if (conn != null) {
          conn.close()
        }
 
      }
    })

上面的env是StreamExecutionEnvironment。

写入HBase也有两种方法，其中写入和写入mysql类似，这里重点说明实现OutputFormat接口进行写入：

package com.my.flink.utils.streaming.hbase;
 
import com.my.flink.utils.config.ConfigKeys;
import org.apache.flink.api.common.io.OutputFormat;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.configuration.Configuration;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.Connection;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.client.Table;
import org.apache.hadoop.hbase.util.Bytes;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
 
import java.io.IOException;
 
/**
 * @Description HBaseOutputFormat
 * @Author jiangxiaozhi
 * @Date 2018/10/16 14:06
 **/
public class HBaseOutputFormat implements OutputFormat<Tuple2<String, String>> {
    private static final Logger logger = LoggerFactory.getLogger(HBaseOutputFormat.class);
 
    private org.apache.hadoop.conf.Configuration conf = null;
    private Connection conn = null;
    private Table table = null;
 
    @Override
    public void configure(Configuration parameters) {
    }
 
    @Override
    public void open(int taskNumber, int numTasks) throws IOException {
        conn = HBaseConnection.getHBaseConn();
        table = conn.getTable(TableName.valueOf(ConfigKeys.HBASE_SINK_TABLE()));
    }
 
    @Override
    public void writeRecord(org.apache.flink.api.java.tuple.Tuple2<String, String> record) throws IOException {
        Put put = new Put(Bytes.toBytes(record.f0));
        put.addColumn(Bytes.toBytes(ConfigKeys.HBASE_SINK_CF()), Bytes.toBytes("test1"), Bytes.toBytes(record.f1));
        table.put(put);
    }
 
    @Override
    public void close() throws IOException {
        if (table != null) {
            table.close();
        }
        if (conn != null) {
            conn.close();
        }
    }
}

在使用时：

读取HBase：
1.如果是HBaseReader
env.addSource(new HBaseReader())//产生DataStream
2.如果是TableInputFormat，产生DataStream见方式二，env.createInput.....
 
存储到HBase：
1.如果是HBaseWritter
env.addSource(new HBaseWriter())//HBaseWritter没有实现，可参看JdbcWriter
2.dataStream.writeUsingOutputFormat(new HBaseOutputFormat())