package filters;
// cc WhileMatchFilterExample Example of using a filter to skip entire rows based on another filter's results
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.KeyValue;
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.RowFilter;
import org.apache.hadoop.hbase.filter.WhileMatchFilter;
import org.apache.hadoop.hbase.util.Bytes;
import util.HBaseHelper;
import java.io.IOException;
public class WhileMatchFilterExample {
public static void main(String[] args) throws IOException {
Configuration conf = HBaseConfiguration.create();
HBaseHelper helper = HBaseHelper.getHelper(conf);
helper.dropTable("testtable");
helper.createTable("testtable", "colfam1");
System.out.println("Adding rows to table...");
helper.fillTable("testtable", 1, 10, 1, 2, true, false, "colfam1");
HTable table = new HTable(conf, "testtable");
// vv WhileMatchFilterExample
Filter filter1 = /*[*/new RowFilter(CompareFilter.CompareOp.NOT_EQUAL,
new BinaryComparator(Bytes.toBytes("row-05")));/*]*/
Scan scan = new Scan();
scan.setFilter(filter1);
ResultScanner scanner1 = table.getScanner(scan);
// ^^ WhileMatchFilterExample
System.out.println("Results of scan #1:");
int n = 0;
// vv WhileMatchFilterExample
for (Result result : scanner1) {
for (KeyValue kv : result.raw()) {
System.out.println("KV: " + kv + ", Value: " +
Bytes.toString(kv.getValue()));
// ^^ WhileMatchFilterExample
n++;
// vv WhileMatchFilterExample
}
}
scanner1.close();
Filter filter2 = new /*[*/WhileMatchFilter(filter1);/*]*/
scan.setFilter(filter2);
ResultScanner scanner2 = table.getScanner(scan);
// ^^ WhileMatchFilterExample
System.out.println("Total KeyValue count for scan #1: " + n);
n = 0;
System.out.println("Results of scan #2:");
// vv WhileMatchFilterExample
for (Result result : scanner2) {
for (KeyValue kv : result.raw()) {
System.out.println("KV: " + kv + ", Value: " +
Bytes.toString(kv.getValue()));
// ^^ WhileMatchFilterExample
n++;
// vv WhileMatchFilterExample
}
}
scanner2.close();
// ^^ WhileMatchFilterExample
System.out.println("Total KeyValue count for scan #2: " + n);
}
}