@Test
  public void testPrefixFilter() throws Exception {
    // Grab rows from group one (half of total)
    long expectedRows = this.numRows / 2;
    long expectedKeys = this.colsPerRow;
    Scan s = new Scan();
    s.setFilter(new PrefixFilter(Bytes.toBytes("testRowOne")));
    verifyScan(s, expectedRows, expectedKeys);
  }
Test filters at the HRegion doorstep.
hbase-server/src/test/java/org/apache/hadoop/hbase/filter/TestFilter.java