Apache HBase 2.0 API - Sample Java Program

The below Java program uses the HBase 2.0 API and performs the following:

1. Create Table
2. Put Row
3. Get Row
4. Scan Rows
5. Delete Column
6. Disable Table
7. Delete Table

package nag.arvind.gudiseva;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.HColumnDescriptor;
import org.apache.hadoop.hbase.HTableDescriptor;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.*;
import org.apache.hadoop.hbase.util.Bytes;

import java.io.IOException;

/** * Created by Nag Arvind Gudiseva on 6/4/2015. */public class EmployeeHBase {

    Connection connection;

    public EmployeeHBase(Connection connection) {
        this.connection = connection;
    }

    void createTable (String tableStr, String colStr1, String colStr2) throws IOException {

        HTableDescriptor tableDescriptor = new HTableDescriptor(TableName.valueOf(tableStr));

        HColumnDescriptor columnFamily1 = new HColumnDescriptor(colStr1);
        tableDescriptor.addFamily(columnFamily1);

        HColumnDescriptor columnFamily2 = new HColumnDescriptor(colStr2);
        tableDescriptor.addFamily(columnFamily2);

        HBaseAdmin admin = (HBaseAdmin) connection.getAdmin();

        System.out.println("Creating table ...");
        admin.createTable(tableDescriptor);
        System.out.println(tableDescriptor.toString());
        System.out.println("... table created!");

        admin.close();

    }

    void putRow(String tableStr, String rowStr, String colStr, String qlfrStr, String valueStr) throws IOException {

        Table table = connection.getTable(TableName.valueOf(tableStr));
        System.out.println("Connecting to table ...");
        Put p = new Put(Bytes.toBytes(rowStr));
        p.addColumn(Bytes.toBytes(colStr), Bytes.toBytes(qlfrStr), Bytes.toBytes(valueStr));
        table.put(p);
        System.out.println("... Added records to table!");

        table.close();

    }

    void getRow(String tableStr, String rowStr, String colStr, String qlfrStr) throws IOException {

        Table table = connection.getTable(TableName.valueOf(tableStr));
        System.out.println("Connecting to table ...");
        Get g = new Get(Bytes.toBytes(rowStr));
        Result r = table.get(g);
        byte [] value = r.getValue(Bytes.toBytes(colStr), Bytes.toBytes(qlfrStr));
        String valueStr = Bytes.toString(value);
        System.out.println("... GET: " + valueStr);

        table.close();

    }

    void scanRows(String tableStr, String colStr, String qlfrStr) throws IOException {

        Table table = connection.getTable(TableName.valueOf(tableStr));
        System.out.println("Connecting to table ...");
        Scan s = new Scan();
        s.addColumn(Bytes.toBytes(colStr), Bytes.toBytes(qlfrStr));
        ResultScanner scanner = table.getScanner(s);

        try {
            for (Result row : scanner) {
                System.out.println("... Found row: " + row);
            }
        }
        finally {
            scanner.close();
        }

        table.close();

    }

    void deleteColumn (String tableStr, String colStr) throws IOException {

        HBaseAdmin admin = (HBaseAdmin) connection.getAdmin();

        System.out.println("Deleting Column ...");
        admin.deleteColumn(tableStr, colStr);
        System.out.println("... Column " + colStr + " from table " + tableStr + " deleted!");

        admin.close();

    }

    void disableTable (String tableStr) throws IOException {

        HBaseAdmin admin = (HBaseAdmin) connection.getAdmin();

        System.out.println("Disabling table ...");
        admin.disableTable(tableStr);
        System.out.println("... " + tableStr + " table disabled!");

        admin.close();

    }

    void deleteTable (String tableStr) throws IOException {

        HBaseAdmin admin = (HBaseAdmin) connection.getAdmin();

        System.out.println("Deleting table ...");
        admin.deleteTable(tableStr);
        System.out.println("... " + tableStr + " table deleted!");

        admin.close();

    }

    public static void main(String[] args) throws IOException {

        Configuration config = HBaseConfiguration.create();
        Connection conn = ConnectionFactory.createConnection(config);
        RegionLocator regionLocator = conn.getRegionLocator(TableName.valueOf("Employee"));  // For future implementation
        EmployeeHBase employeeHBase = new EmployeeHBase(conn);

        employeeHBase.createTable("Employee", "personal", "official");

        employeeHBase.putRow("Employee", "emp102", "official", "name", "Arvind");

        employeeHBase.getRow("Employee", "emp102", "official", "name");

        employeeHBase.scanRows("Employee", "official", "name");

        employeeHBase.deleteColumn("Employee", "official");

        employeeHBase.disableTable("Employee");

        employeeHBase.deleteTable("Employee");

        regionLocator.close();
        conn.close();
    }
}

Reference: 
https://hbase.apache.org/apidocs/