Example filtering specific rows.

ch04/src/main/java/filters/ValueNotNullFilterExample.java

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+package filters;
+
+// cc ValueNotNullFilterExample Example using the single value based filter in combination
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hbase.Cell;
+import org.apache.hadoop.hbase.HBaseConfiguration;
+import org.apache.hadoop.hbase.TableName;
+import org.apache.hadoop.hbase.client.Connection;
+import org.apache.hadoop.hbase.client.ConnectionFactory;
+import org.apache.hadoop.hbase.client.Delete;
+import org.apache.hadoop.hbase.client.Put;
+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.client.Table;
+import org.apache.hadoop.hbase.filter.CompareFilter;
+import org.apache.hadoop.hbase.filter.FilterList;
+import org.apache.hadoop.hbase.filter.NullComparator;
+import org.apache.hadoop.hbase.filter.SingleColumnValueFilter;
+import org.apache.hadoop.hbase.util.Bytes;
+import util.HBaseHelper;
+
+import java.io.IOException;
+
+public class ValueNotNullFilterExample {
+
+  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, 5, "colfam1");
+
+    Connection connection = ConnectionFactory.createConnection(conf);
+    Table table = connection.getTable(TableName.valueOf("testtable"));
+
+    Put put = new Put(Bytes.toBytes("row-5"))
+      .addColumn(Bytes.toBytes("colfam1"), Bytes.toBytes("col-6"),
+        Bytes.toBytes("val-6"));
+    table.put(put);
+    put = new Put(Bytes.toBytes("row-8"))
+      .addColumn(Bytes.toBytes("colfam1"), Bytes.toBytes("col-6"),
+        Bytes.toBytes("val-6"));
+    table.put(put);
+
+    Delete delete = new Delete(Bytes.toBytes("row-5"))
+      .addColumn(Bytes.toBytes("colfam1"), Bytes.toBytes("col-3"));
+    table.delete(delete);
+
+    // vv ValueNotNullFilterExample
+    SingleColumnValueFilter filter = new SingleColumnValueFilter(
+      Bytes.toBytes("colfam1"), Bytes.toBytes("col-6"),
+      CompareFilter.CompareOp.NOT_EQUAL, new NullComparator());
+    filter.setFilterIfMissing(true);
+    SingleColumnValueFilter filter2 = new SingleColumnValueFilter(
+      Bytes.toBytes("colfam1"), Bytes.toBytes("col-3"),
+      CompareFilter.CompareOp.NOT_EQUAL, new NullComparator());
+    filter2.setFilterIfMissing(true);
+
+    FilterList list = new FilterList();
+    list.addFilter(filter);
+    list.addFilter(filter2);
+
+    Scan scan = new Scan();
+    scan.setFilter(list);
+
+    ResultScanner scanner = table.getScanner(scan);
+    // ^^ ValueNotNullFilterExample
+    System.out.println("Results of scan:");
+    // vv ValueNotNullFilterExample
+    for (Result result : scanner) {
+      for (Cell cell : result.rawCells()) {
+        System.out.println("Cell: " + cell + ", Value: " +
+          Bytes.toString(cell.getValueArray(), cell.getValueOffset(),
+            cell.getValueLength()));
+      }
+    }
+    scanner.close();
+    // ^^ ValueNotNullFilterExample
+    table.close();
+    connection.close();
+  }
+}