Every once in a while you need to modify an HBase KeyValue in various ways depending on conditional logic. This is a simple builder pattern applied to a KeyValue with a copy constructor.

KeyValueBuilder.java

package com.simplymeasured.doormouse.mapreduce.utils;

import org.apache.hadoop.hbase.KeyValue;

/**
 * Stupid-simple builder pattern applied to the HBase KeyValue class.
 *
 * Makes it easier to manipulate KeyValues in map/reduce jobs
 *
 * @author rob@simplymeasured.com
 * @since 3/11/13
 */
public class KeyValueBuilder {
    private byte[] row;
    private byte[] family;
    private byte[] qualifier;
    private byte[] value;
    private long timestamp;

    public KeyValueBuilder() {
    }

    public KeyValueBuilder(KeyValue kv) {
        this.row = kv.getRow();
        this.family = kv.getFamily();
        this.qualifier = kv.getQualifier();
        this.value = kv.getValue();
        this.timestamp = kv.getTimestamp();
    }

    public byte[] getRow() {
        return row;
    }

    public KeyValueBuilder setRow(byte[] row) {
        this.row = row;

        return this;
    }

    public byte[] getFamily() {
        return family;
    }

    public KeyValueBuilder setFamily(byte[] family) {
        this.family = family;

        return this;
    }

    public byte[] getQualifier() {
        return qualifier;
    }

    public KeyValueBuilder setQualifier(byte[] qualifier) {
        this.qualifier = qualifier;

        return this;
    }

    public byte[] getValue() {
        return value;
    }

    public KeyValueBuilder setValue(byte[] value) {
        this.value = value;

        return this;
    }

    public long getTimestamp() {
        return timestamp;
    }

    public KeyValueBuilder setTimestamp(long timestamp) {
        this.timestamp = timestamp;

        return this;
    }

    public KeyValue build() {
        return new KeyValue(row, family, qualifier, timestamp, value);
    }
}