org.apache.flink.connector.pulsar.source.MessageSerializer Maven / Gradle / Ivy
/*
* Licensed 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.connector.pulsar.source;
import org.apache.flink.api.common.serialization.SerializationSchema;
import org.apache.pulsar.client.api.TypedMessageBuilder;
import java.io.Serializable;
/**
* An interface for the deserialization of Pulsar messages.
*/
public interface MessageSerializer extends Serializable {
/**
* Serializes the incoming element to a specified type.
*
* @param element The incoming element to be serialized
*/
void serialize(T element, TypedMessageBuilder messageBuilder);
/**
* Initialization method for the schema. It is called before the actual working methods
* {@link #serialize(Object, TypedMessageBuilder)} and thus suitable for one time setup work.
*
* The provided {@link SerializationSchema.InitializationContext} can be used to access additional features such as e.g.
* registering user metrics.
*
* @param context Contextual information that can be used during initialization.
*/
default void open(SerializationSchema.InitializationContext context) throws Exception {
}
/**
* Wraps a Flink {@link SerializationSchema} to a {@link MessageSerializer}.
*
* @param valueSerializer the serializer class used to serialize the value.
* @param the value type.
* @return A {@link MessageSerializer} that deserialize the value with the given deserializer.
*/
static MessageSerializer valueOnly(SerializationSchema valueSerializer) {
return new MessageSerializer() {
@Override
public void open(SerializationSchema.InitializationContext context) throws Exception {
valueSerializer.open(context);
}
@Override
public void serialize(V element, TypedMessageBuilder messageBuilder) {
messageBuilder.value(valueSerializer.serialize(element));
}
};
}
}