package filters;
// cc DependentColumnFilterExample Example using a filter to include only specific column families
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.KeyValue;
import org.apache.hadoop.hbase.client.Get;
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.BinaryPrefixComparator;
import org.apache.hadoop.hbase.filter.CompareFilter;
import org.apache.hadoop.hbase.filter.DependentColumnFilter;
import org.apache.hadoop.hbase.filter.Filter;
import org.apache.hadoop.hbase.filter.RegexStringComparator;
import org.apache.hadoop.hbase.filter.WritableByteArrayComparable;
import org.apache.hadoop.hbase.util.Bytes;
import util.HBaseHelper;
import java.io.IOException;
public class DependentColumnFilterExample {
private static HTable table = null;
// vv DependentColumnFilterExample
private static void filter(boolean drop,
CompareFilter.CompareOp operator,
WritableByteArrayComparable comparator)
throws IOException {
Filter filter;
if (comparator != null) {
filter = new DependentColumnFilter(Bytes.toBytes("colfam1"), // co DependentColumnFilterExample-1-CreateFilter Create the filter with various options.
Bytes.toBytes("col-5"), drop, operator, comparator);
} else {
filter = new DependentColumnFilter(Bytes.toBytes("colfam1"),
Bytes.toBytes("col-5"), drop);
}
Scan scan = new Scan();
scan.setFilter(filter);
ResultScanner scanner = table.getScanner(scan);
// ^^ DependentColumnFilterExample
System.out.println("Results of scan:");
// vv DependentColumnFilterExample
for (Result result : scanner) {
for (KeyValue kv : result.raw()) {
System.out.println("KV: " + kv + ", Value: " +
Bytes.toString(kv.getValue()));
}
}
scanner.close();
Get get = new Get(Bytes.toBytes("row-5"));
get.setFilter(filter);
Result result = table.get(get);
// ^^ DependentColumnFilterExample
System.out.println("Result of get: ");
// vv DependentColumnFilterExample
for (KeyValue kv : result.raw()) {
System.out.println("KV: " + kv + ", Value: " +
Bytes.toString(kv.getValue()));
}
// ^^ DependentColumnFilterExample
System.out.println("");
// vv DependentColumnFilterExample
}
public static void main(String[] args) throws IOException {
// ^^ DependentColumnFilterExample
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, 10, 10, true, "colfam1", "colfam2");
table = new HTable(conf, "testtable");
// vv DependentColumnFilterExample
filter(true, CompareFilter.CompareOp.NO_OP, null);
filter(false, CompareFilter.CompareOp.NO_OP, null); // co DependentColumnFilterExample-2-Filter Call filter method with various options.
filter(true, CompareFilter.CompareOp.EQUAL,
new BinaryPrefixComparator(Bytes.toBytes("val-5")));
filter(false, CompareFilter.CompareOp.EQUAL,
new BinaryPrefixComparator(Bytes.toBytes("val-5")));
filter(true, CompareFilter.CompareOp.EQUAL,
new RegexStringComparator(".*\\.5"));
filter(false, CompareFilter.CompareOp.EQUAL,
new RegexStringComparator(".*\\.5"));
}
// ^^ DependentColumnFilterExample
}