com.hmsonline.storm.cassandra.bolt.mapper.DefaultTupleCounterMapper Maven / Gradle / Ivy

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package com.hmsonline.storm.cassandra.bolt.mapper;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import backtype.storm.tuple.Fields;
import backtype.storm.tuple.Tuple;

/**
 * For counter columns, an increment amount is required, the following fields
 * must be specified: rowKey, and incrementAmount, all remaining fields are
 * assumed to be column names to be incremented by the specified amount.
 */
public class DefaultTupleCounterMapper implements TupleCounterMapper {

    private static final long serialVersionUID = 1L;
    private String rowKeyField;
    private String columnFamily;
    private String incrementAmountField;
    private String keyspace;

    public DefaultTupleCounterMapper(String keyspace, String columnFamily, String rowKeyField, String incrementAmountField) {
        this.columnFamily = columnFamily;
        this.rowKeyField = rowKeyField;
        this.incrementAmountField = incrementAmountField;
        this.keyspace = keyspace;
    }

    @Override
    public String mapToColumnFamily(Tuple tuple) {
        return this.columnFamily;
    }
    
    @Override
    public String mapToKeyspace(Tuple tuple) {
        return this.keyspace;
    }

    @Override
    public String mapToRowKey(Tuple tuple) {
        return tuple.getValueByField(this.rowKeyField).toString();
    }

    @Override
    public long mapToIncrementAmount(Tuple tuple) {
        return tuple.getLongByField(incrementAmountField);
    }

    @Override
    public List mapToColumnList(Tuple tuple) {
        Fields fields = tuple.getFields();
        List result = new ArrayList();
        Iterator it = fields.iterator();
        while (it.hasNext()) {
            String fieldName = it.next();
            if (!fieldName.equals(rowKeyField) && !fieldName.equals(incrementAmountField))
                result.add(tuple.getValueByField(fieldName).toString());
        }
        return result;
    }

}