HTableFactory.java

package brickhouse.hbase;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.client.HTable;
import org.apache.hadoop.hive.ql.exec.UDFArgumentException;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspectorUtils;
import org.apache.hadoop.hive.serde2.objectinspector.StandardConstantMapObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.primitive.StringObjectInspector;
import org.apache.log4j.Logger;

import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;

/**
 * Common code to access HTables
 *
 * @author jeromebanks
 */
public class HTableFactory {
    private static final Logger LOG = Logger.getLogger(HTableFactory.class);

    static String FAMILY_TAG = "family";
    static String QUALIFIER_TAG = "qualifier";
    static String TABLE_NAME_TAG = "table_name";
    static String ZOOKEEPER_QUORUM_TAG = "hbase.zookeeper.quorum";
    static String AUTOFLUSH_TAG = "hbase.client.autoflush";

    private static Map<String, HTable> htableMap = new HashMap<String, HTable>();
    private static Configuration hbConfig;


    public static HTable getHTable(Map<String, String> configMap) throws IOException {
        String tableName = configMap.get(TABLE_NAME_TAG);
        HTable table = htableMap.get(tableName);
        if (table == null) {
            if (hbConfig == null) {
                Configuration config = new Configuration(true);
                config.set("hbase.zookeeper.quorum", configMap.get(ZOOKEEPER_QUORUM_TAG));
                for (Entry<String, String> entry : configMap.entrySet()) {
                    config.set(entry.getKey(), entry.getValue());
                }
                hbConfig = HBaseConfiguration.create(config);
            }

            table = new HTable(hbConfig, tableName);

            if (configMap.containsKey(AUTOFLUSH_TAG)) {
                Boolean flushFlag = Boolean.valueOf(configMap.get(AUTOFLUSH_TAG));
                table.setAutoFlush(flushFlag);
            }

            htableMap.put(tableName, table);
        }

        return table;
    }

    public static Map<String, String> getConfigFromConstMapInspector(ObjectInspector objInspector) throws UDFArgumentException {
        if (!(ObjectInspectorUtils.isConstantObjectInspector(objInspector))
                || !(objInspector instanceof StandardConstantMapObjectInspector)) {
            throw new UDFArgumentException("HBase parameters must be a constant map");
        }
        StandardConstantMapObjectInspector constMapInsp = (StandardConstantMapObjectInspector) objInspector;
        Map<?, ?> uninspMap = constMapInsp.getWritableConstantValue();
        System.out.println(" Uninsp Map = " + uninspMap + " size is " + uninspMap.size());
        Map<String, String> configMap = new HashMap<String, String>();
        for (Object uninspKey : uninspMap.keySet()) {
            Object uninspVal = uninspMap.get(uninspKey);
            String key = ((StringObjectInspector) constMapInsp.getMapKeyObjectInspector()).getPrimitiveJavaObject(uninspKey);
            String val = ((StringObjectInspector) constMapInsp.getMapValueObjectInspector()).getPrimitiveJavaObject(uninspVal);

            LOG.info(" Key " + key + " VAL = " + configMap.get(key));
            System.out.println(" Key " + key + " VAL = " + configMap.get(key));
            configMap.put(key, val);
        }
        return configMap;
    }


    /**
     * Throws RuntimeException if config is incomplete.
     *
     * @param configIn
     */
    public static void checkConfig(Map<String, String> configIn) {
        if (!configIn.containsKey(FAMILY_TAG) ||
                !configIn.containsKey(QUALIFIER_TAG) ||
                !configIn.containsKey(TABLE_NAME_TAG) ||
                !configIn.containsKey(ZOOKEEPER_QUORUM_TAG)) {
            String errorMsg = "Error while doing HBase operation with config " + configIn + " ; Config is missing for: " + FAMILY_TAG + " or " +
                    QUALIFIER_TAG + " or " + TABLE_NAME_TAG + " or " + ZOOKEEPER_QUORUM_TAG;
            LOG.error(errorMsg);
            throw new RuntimeException(errorMsg);
        }
    }

}