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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.table.api;
import org.apache.flink.annotation.PublicEvolving;
import org.apache.flink.table.expressions.ApiExpressionUtils;
import org.apache.flink.table.expressions.Expression;
/**
* Session window.
*
* For streaming tables you can specify grouping by a event-time or processing-time attribute.
*
*
For batch tables you can specify grouping on a timestamp or long attribute.
*/
@PublicEvolving
public final class SessionWithGap {
/** The time interval of inactivity before a window is closed. */
private final Expression gap;
SessionWithGap(Expression gap) {
this.gap = ApiExpressionUtils.unwrapFromApi(gap);
}
/**
* Specifies the time attribute on which rows are grouped.
*
*
For streaming tables you can specify grouping by a event-time or processing-time
* attribute.
*
*
For batch tables you can specify grouping on a timestamp or long attribute.
*
* @param timeField time attribute for streaming and batch tables
* @return a tumbling window on event-time
*/
public SessionWithGapOnTime on(Expression timeField) {
return new SessionWithGapOnTime(timeField, gap);
}
}