package filters;
// cc RowFilterExample Example using a filter to select specific rows
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.client.HTable;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.client.ResultScanner;
import org.apache.hadoop.hbase.client.Scan;
import org.apache.hadoop.hbase.filter.BinaryComparator;
import org.apache.hadoop.hbase.filter.CompareFilter;
import org.apache.hadoop.hbase.filter.Filter;
import org.apache.hadoop.hbase.filter.RegexStringComparator;
import org.apache.hadoop.hbase.filter.RowFilter;
import org.apache.hadoop.hbase.filter.SubstringComparator;
import org.apache.hadoop.hbase.util.Bytes;
import util.HBaseHelper;
import java.io.IOException;
public class RowFilterExample {
public static void main(String[] args) throws IOException {
Configuration conf = HBaseConfiguration.create();
HBaseHelper helper = HBaseHelper.getHelper(conf);
helper.dropTable("testtable");
helper.createTable("testtable", "colfam1", "colfam2");
System.out.println("Adding rows to table...");
helper.fillTable("testtable", 1, 100, 100, "colfam1", "colfam2");
HTable table = new HTable(conf, "testtable");
// vv RowFilterExample
Scan scan = new Scan();
scan.addColumn(Bytes.toBytes("colfam1"), Bytes.toBytes("col-0"));
Filter filter1 = new RowFilter(CompareFilter.CompareOp.LESS_OR_EQUAL, // co RowFilterExample-1-Filter1 Create filter, while specifying the comparison operator and comparator. Here an exact match is needed.
new BinaryComparator(Bytes.toBytes("row-22")));
scan.setFilter(filter1);
ResultScanner scanner1 = table.getScanner(scan);
// ^^ RowFilterExample
System.out.println("Scanning table #1...");
// vv RowFilterExample
for (Result res : scanner1) {
System.out.println(res);
}
scanner1.close();
Filter filter2 = new RowFilter(CompareFilter.CompareOp.EQUAL, // co RowFilterExample-2-Filter2 Another filter, this time using a regular expression to match the row keys.
new RegexStringComparator(".*-.5"));
scan.setFilter(filter2);
ResultScanner scanner2 = table.getScanner(scan);
// ^^ RowFilterExample
System.out.println("Scanning table #2...");
// vv RowFilterExample
for (Result res : scanner2) {
System.out.println(res);
}
scanner2.close();
Filter filter3 = new RowFilter(CompareFilter.CompareOp.EQUAL, // co RowFilterExample-3-Filter3 The third filter uses a substring match approach.
new SubstringComparator("-5"));
scan.setFilter(filter3);
ResultScanner scanner3 = table.getScanner(scan);
// ^^ RowFilterExample
System.out.println("Scanning table #3...");
// vv RowFilterExample
for (Result res : scanner3) {
System.out.println(res);
}
scanner3.close();
// ^^ RowFilterExample
}
}