flink-libraries/flink-table/src/main/scala/org/apache/flink/table/sources/StreamTableSource.scala

/*
 * 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.sources

import org.apache.flink.streaming.api.datastream.DataStream
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment

/** Defines an external stream table and provides access to its data.
  *
  * @tparam T Type of the [[DataStream]] created by this [[TableSource]].
  */
trait StreamTableSource[T] extends TableSource {

  /**
    * Returns the data of the table as a [[DataStream]].
    *
    * NOTE: This method is for internal use only for defining a [[TableSource]].
    *       Do not use it in Table API programs.
    */
  def getDataStream(execEnv: StreamExecutionEnvironment): DataStream[T]
}