@Test
  public void testNullValue() throws IOException {
    final TableName tableName = name.getTableName();

    try (Table ht = TEST_UTIL.createTable(tableName, FAMILY)) {
      // Null value
      try {
        Put put = new Put(ROW);
        put.addColumn(FAMILY, QUALIFIER, null);
        ht.put(put);

        Get get = new Get(ROW);
        get.addColumn(FAMILY, QUALIFIER);
        Result result = ht.get(get);
        assertSingleResult(result, ROW, FAMILY, QUALIFIER, null);

        Scan scan = new Scan();
        scan.addColumn(FAMILY, QUALIFIER);
        result = getSingleScanResult(ht, scan);
        assertSingleResult(result, ROW, FAMILY, QUALIFIER, null);

        Delete delete = new Delete(ROW);
        delete.addColumns(FAMILY, QUALIFIER);
        ht.delete(delete);

        get = new Get(ROW);
        result = ht.get(get);
        assertEmptyResult(result);

      } catch (Exception e) {
        throw new IOException("Null values should be allowed, but threw exception");
      }
    }
  }
Test basic puts, gets, scans, and deletes for a single row in a multiple family table.
hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestFromClientSide.java