@Test
  public void testDefaultWhiteList() throws Exception {
    assertEquals("", new HiveConf().getVar(ConfVars.HIVE_SERVER2_BUILTIN_UDF_WHITELIST));
    assertEquals("", new HiveConf().getVar(ConfVars.HIVE_SERVER2_BUILTIN_UDF_BLACKLIST));
    FunctionRegistry.setupPermissionsForBuiltinUDFs("", "");
    assertEquals("substr", FunctionRegistry.getFunctionInfo("substr").getDisplayName());
  }
Verify that UDF in the whitelist can be access
@throws Exception
ql/src/test/org/apache/hadoop/hive/ql/udf/TestBlockedUdf.java