/*
* 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.flink.cep.pattern.conditions;
import org.apache.flink.util.Preconditions;
/**
* A {@link IterativeCondition condition} which filters elements of the given type.
* An element is filtered out iff it is not assignable to the given subtype of {@code T}.
*
* @param <T> Type of the elements to be filtered
*/
public class SubtypeCondition<T> extends SimpleCondition<T> {
private static final long serialVersionUID = -2990017519957561355L;
/** The subtype to filter for. */
private final Class<? extends T> subtype;
public SubtypeCondition(final Class<? extends T> subtype) {
this.subtype = Preconditions.checkNotNull(subtype, "The subtype cannot be null.");
}
@Override
public boolean filter(T value) throws Exception {
return subtype.isAssignableFrom(value.getClass());
}
}