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/*
* Copyright 2017-2021 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.data.cassandra.core.mapping;
import java.util.function.UnaryOperator;
import org.springframework.util.Assert;
/**
* Interface and default implementation of a naming strategy. Defaults to table name based on {@link Class} and column
* name based on property names.
*
* NOTE: Can also be used as an adapter. Create a lambda or an anonymous subclass and override any settings to implement
* a different strategy on the fly.
*
* @author Mark Paluch
* @since 3.0
*/
public interface NamingStrategy {
/**
* Empty implementation of the interface utilizing only the default implementation.
*
* Using this avoids creating essentially the same class over and over again.
*/
NamingStrategy INSTANCE = new NamingStrategy() {};
/**
* Naming strategy that renders CamelCase name parts to {@code snake_case}.
*/
NamingStrategy SNAKE_CASE = new SnakeCaseNamingStrategy();
/**
* Create a table name from the given {@link CassandraPersistentEntity}.
*/
default String getTableName(CassandraPersistentEntity entity) {
Assert.notNull(entity, "CassandraPersistentEntity must not be null");
return entity.getType().getSimpleName();
}
/**
* Create a user-defined type name from the given {@link CassandraPersistentEntity}.
*/
default String getUserDefinedTypeName(CassandraPersistentEntity entity) {
Assert.notNull(entity, "CassandraPersistentEntity must not be null");
return entity.getType().getSimpleName();
}
/**
* Create a column name from the given {@link CassandraPersistentProperty property}.
*/
default String getColumnName(CassandraPersistentProperty property) {
Assert.notNull(property, "CassandraPersistentProperty must not be null");
return property.getName();
}
/**
* Apply a {@link UnaryOperator transformation function} to create a new {@link NamingStrategy}
* that applies the given transformation to each name component.
*
* Example:
*
* NamingStrategy lower = NamingStrategy.INSTANCE.transform(String::toLowerCase);
*
*
* @param mappingFunction must not be {@literal null}.
* @return the {@link NamingStrategy} that applies the given {@link UnaryOperator transformation function}.
*/
default NamingStrategy transform(UnaryOperator mappingFunction) {
Assert.notNull(mappingFunction, "Mapping function must not be null");
NamingStrategy previous = this;
return new TransformingNamingStrategy(previous, mappingFunction);
}
}