org.springframework.kafka.support.converter.Jackson2JavaTypeMapper Maven / Gradle / Ivy
/*
* Copyright 2017-2019 the original author or authors.
*
* 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
*
* https://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.springframework.kafka.support.converter;
import org.apache.kafka.common.header.Headers;
import com.fasterxml.jackson.databind.JavaType;
/**
* Strategy for setting metadata on messages such that one can create the class that needs
* to be instantiated when receiving a message.
*
* @author Mark Pollack
* @author James Carr
* @author Sam Nelson
* @author Andreas Asplund
* @author Gary Russell
*
* @since 2.1
*/
public interface Jackson2JavaTypeMapper extends ClassMapper {
/**
* The precedence for type conversion - inferred from the method parameter or message
* headers. Only applies if both exist.
*/
enum TypePrecedence {
INFERRED, TYPE_ID
}
void fromJavaType(JavaType javaType, Headers headers);
JavaType toJavaType(Headers headers);
TypePrecedence getTypePrecedence();
/**
* Set the precedence for evaluating type information in message properties.
* When using {@code @KafkaListener} at the method level, the framework attempts
* to determine the target type for payload conversion from the method signature.
* If so, this type is provided by the {@code MessagingMessageListenerAdapter}.
* By default, if the type is concrete (not abstract, not an interface), this will
* be used ahead of type information provided in the {@code __TypeId__} and
* associated headers provided by the sender.
*
If you wish to force the use of the {@code __TypeId__} and associated headers
* (such as when the actual type is a subclass of the method argument type),
* set the precedence to {@link Jackson2JavaTypeMapper.TypePrecedence#TYPE_ID}.
* @param typePrecedence the precedence.
* @since 2.2
*/
default void setTypePrecedence(TypePrecedence typePrecedence) {
throw new UnsupportedOperationException("This mapper does not support this method");
}
void addTrustedPackages(String... packages);
/**
* Remove the type information headers.
* @param headers the headers.
* @since 2.2
*/
default void removeHeaders(Headers headers) {
// NOSONAR
}
}