org.apache.kafka.connect.storage.Converter 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,
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* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.kafka.connect.storage;
import org.apache.kafka.common.config.ConfigDef;
import org.apache.kafka.common.header.Headers;
import org.apache.kafka.connect.data.Schema;
import org.apache.kafka.connect.data.SchemaAndValue;
import java.util.Map;
/**
* The Converter interface provides support for translating between Kafka Connect's runtime data format
* and byte[]. Internally, this likely includes an intermediate step to the format used by the serialization
* layer (e.g. JsonNode, GenericRecord, Message).
*/
public interface Converter {
/**
* Configure this class.
* @param configs configs in key/value pairs
* @param isKey whether is for key or value
*/
void configure(Map configs, boolean isKey);
/**
* Convert a Kafka Connect data object to a native object for serialization.
* @param topic the topic associated with the data
* @param schema the schema for the value
* @param value the value to convert
* @return the serialized value
*/
byte[] fromConnectData(String topic, Schema schema, Object value);
/**
* Convert a Kafka Connect data object to a native object for serialization,
* potentially using the supplied topic and headers in the record as necessary.
*
* Connect uses this method directly, and for backward compatibility reasons this method
* by default will call the {@link #fromConnectData(String, Schema, Object)} method.
* Override this method to make use of the supplied headers.
* @param topic the topic associated with the data
* @param headers the headers associated with the data; any changes done to the headers
* are applied to the message sent to the broker
* @param schema the schema for the value
* @param value the value to convert
* @return the serialized value
*/
default byte[] fromConnectData(String topic, Headers headers, Schema schema, Object value) {
return fromConnectData(topic, schema, value);
}
/**
* Convert a native object to a Kafka Connect data object.
* @param topic the topic associated with the data
* @param value the value to convert
* @return an object containing the {@link Schema} and the converted value
*/
SchemaAndValue toConnectData(String topic, byte[] value);
/**
* Convert a native object to a Kafka Connect data object,
* potentially using the supplied topic and headers in the record as necessary.
*
* Connect uses this method directly, and for backward compatibility reasons this method
* by default will call the {@link #toConnectData(String, byte[])} method.
* Override this method to make use of the supplied headers.
* @param topic the topic associated with the data
* @param headers the headers associated with the data
* @param value the value to convert
* @return an object containing the {@link Schema} and the converted value
*/
default SchemaAndValue toConnectData(String topic, Headers headers, byte[] value) {
return toConnectData(topic, value);
}
/**
* Configuration specification for this converter.
* @return the configuration specification; may not be null
*/
default ConfigDef config() {
return new ConfigDef();
}
}