/tags/release-0.1-rc2/hive/external/ql/src/java/org/apache/hadoop/hive/ql/udf/generic/GenericUDFOPNull.java
Java | 59 lines | 31 code | 7 blank | 21 comment | 4 complexity | c83f93d198146896fb9738a389d8615b MD5 | raw file
Possible License(s): Apache-2.0, BSD-3-Clause, JSON, CPL-1.0
- /**
- * Licensed to the Apache Software Foundation (ASF) under one
- * or more contributor license agreements. See the NOTICE file
- * distributed with this work for additional information
- * regarding copyright ownership. The ASF licenses this file
- * to you under the Apache License, Version 2.0 (the
- * "License"); you may not use this file except in compliance
- * with the License. You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
- package org.apache.hadoop.hive.ql.udf.generic;
- import org.apache.hadoop.hive.ql.exec.Description;
- import org.apache.hadoop.hive.ql.exec.UDFArgumentException;
- import org.apache.hadoop.hive.ql.exec.UDFArgumentLengthException;
- import org.apache.hadoop.hive.ql.metadata.HiveException;
- import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
- import org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorFactory;
- import org.apache.hadoop.io.BooleanWritable;
- /**
- * GenericUDFOPNull.
- *
- */
- @Description(name = "isnull", value = "_FUNC_ a - Returns true if a is NULL and false otherwise")
- public class GenericUDFOPNull extends GenericUDF {
- private BooleanWritable result = new BooleanWritable();
- @Override
- public ObjectInspector initialize(ObjectInspector[] arguments)
- throws UDFArgumentException {
- if (arguments.length != 1) {
- throw new UDFArgumentLengthException(
- "The operator 'IS NULL' only accepts 1 argument.");
- }
- return PrimitiveObjectInspectorFactory.writableBooleanObjectInspector;
- }
- @Override
- public Object evaluate(DeferredObject[] arguments) throws HiveException {
- result.set(arguments[0].get() == null);
- return result;
- }
- @Override
- public String getDisplayString(String[] children) {
- assert (children.length == 1);
- return children[0] + " is null";
- }
- }