org.apache.flink.runtime.state.keyed.KeyedListStateDescriptor Maven / Gradle / Ivy
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* 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.runtime.state.keyed;
import org.apache.flink.api.common.typeutils.TypeSerializer;
import org.apache.flink.api.common.typeutils.base.ListSerializer;
import org.apache.flink.runtime.state.InternalStateType;
import org.apache.flink.util.Preconditions;
import java.util.List;
/**
* The descriptor for {@link KeyedListState}.
*
* @param Type of the keys in the state.
* @param Type of the elements in the state.
*/
public final class KeyedListStateDescriptor extends KeyedStateDescriptor, KeyedListState> {
private static final long serialVersionUID = 1L;
/**
* Constructor with given name and the serializers for the keys and the
* elements in the state.
*
* @param name The name of the state.
* @param keySerializer The serializer for the keys in the state.
* @param elementSerializer The serializer for the elements in the state.
*/
public KeyedListStateDescriptor(
final String name,
final TypeSerializer keySerializer,
final TypeSerializer elementSerializer
) {
this(name, keySerializer, new ListSerializer<>(elementSerializer));
}
/**
* Constructor with given name and the serializers for the keys and the
* lists in the state.
*
* @param name The name of the state.
* @param keySerializer The serializer for the keys in the state.
* @param listSerializer The serializer for the lists in the state.
*/
public KeyedListStateDescriptor(
final String name,
final TypeSerializer keySerializer,
final ListSerializer listSerializer
) {
super(name, InternalStateType.KEYED_LIST, keySerializer, listSerializer);
}
@Override
public ListSerializer getValueSerializer() {
TypeSerializer> listSerializer = super.getValueSerializer();
Preconditions.checkState(listSerializer instanceof ListSerializer);
return (ListSerializer) listSerializer;
}
/**
* Returns the serializer for the elements in the state.
*
* @return The serializer for the elements in the state.
*/
public TypeSerializer getElementSerializer() {
return getValueSerializer().getElementSerializer();
}
@Override
public KeyedListState bind(KeyedStateBinder stateBinder) throws Exception {
return stateBinder.createKeyedListState(this);
}
}