org.apache.flink.streaming.api.functions.sink.SinkFunction Maven / Gradle / Ivy
/*
* 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.streaming.api.functions.sink;
import org.apache.flink.annotation.Public;
import org.apache.flink.api.common.functions.Function;
import java.io.Serializable;
/**
* Interface for implementing user defined sink functionality.
*
* @param Input type parameter.
*/
@Public
public interface SinkFunction extends Function, Serializable {
/**
* @deprecated Use {@link #invoke(Object, Context)}.
*/
@Deprecated
default void invoke(IN value) throws Exception {}
/**
* Writes the given value to the sink. This function is called for every record.
*
* You have to override this method when implementing a {@code SinkFunction}, this is a
* {@code default} method for backward compatibility with the old-style method only.
*
* @param value The input record.
* @param context Additional context about the input record.
*
* @throws Exception This method may throw exceptions. Throwing an exception will cause the operation
* to fail and may trigger recovery.
*/
default void invoke(IN value, Context context) throws Exception {
invoke(value);
}
/**
* Context that {@link SinkFunction SinkFunctions } can use for getting additional data about
* an input record.
*
*
The context is only valid for the duration of a
* {@link SinkFunction#invoke(Object, Context)} call. Do not store the context and use
* afterwards!
*
* @param The type of elements accepted by the sink.
*/
@Public // Interface might be extended in the future with additional methods.
interface Context {
/** Returns the current processing time. */
long currentProcessingTime();
/** Returns the current event-time watermark. */
long currentWatermark();
/**
* Returns the timestamp of the current input record or {@code null} if the element does not
* have an assigned timestamp.
*/
Long timestamp();
}
}