DATACASS-84 - Use NamingStrategy for table and column name derivation

pom.xml

@@ -11,7 +11,7 @@
 
 <groupId>org.springframework.data</groupId>
 <artifactId>spring-data-cassandra-parent</artifactId>
-<version>3.0.0.BUILD-SNAPSHOT</version>
+<version>3.0.0.DATACASS-84-SNAPSHOT</version>
 <packaging>pom</packaging>
 
 <name>Spring Data for Apache Cassandra</name>

spring-data-cassandra-distribution/pom.xml

@@ -8,7 +8,7 @@
 <parent>
 <groupId>org.springframework.data</groupId>
 <artifactId>spring-data-cassandra-parent</artifactId>
-<version>3.0.0.BUILD-SNAPSHOT</version>
+<version>3.0.0.DATACASS-84-SNAPSHOT</version>
 <relativePath>../pom.xml</relativePath>
 </parent>
 

spring-data-cassandra/pom.xml

@@ -8,7 +8,7 @@
 <parent>
 <groupId>org.springframework.data</groupId>
 <artifactId>spring-data-cassandra-parent</artifactId>
-<version>3.0.0.BUILD-SNAPSHOT</version>
+<version>3.0.0.DATACASS-84-SNAPSHOT</version>
 <relativePath>../pom.xml</relativePath>
 </parent>
 

spring-data-cassandra/src/main/java/org/springframework/data/cassandra/core/mapping/BasicCassandraPersistentEntity.java

@@ -55,6 +55,8 @@ public class BasicCassandraPersistentEntity<T> extends BasicPersistentEntity<T,
 
 private CqlIdentifier tableName;
 
+private NamingStrategy namingStrategy = NamingStrategy.INSTANCE;
+
 private @Nullable StandardEvaluationContext spelContext;
 
 /**
@@ -106,13 +108,13 @@ protected CqlIdentifier determineTableName() {
 return determineName(annotation.value(), annotation.forceQuote());
 }
 
-return IdentifierFactory.create(getType().getSimpleName(), false);
+return IdentifierFactory.create(namingStrategy.getTableName(this), false);
 }
 
 CqlIdentifier determineName(String value, boolean forceQuote) {
 
 if (!StringUtils.hasText(value)) {
-return IdentifierFactory.create(getType().getSimpleName(), forceQuote);
+return IdentifierFactory.create(namingStrategy.getTableName(this), forceQuote);
 }
 
 String name = Optional.ofNullable(this.spelContext).map(it -> SpelUtils.evaluate(value, it)).orElse(value);
@@ -199,6 +201,23 @@ public void setTableName(CqlIdentifier tableName) {
 this.tableName = tableName;
 }
 
+/**
+ * Set the {@link NamingStrategy} to use.
+ *
+ * @param namingStrategy must not be {@literal null}.
+ * @since 3.0
+ */
+public void setNamingStrategy(NamingStrategy namingStrategy) {
+
+Assert.notNull(namingStrategy, "NamingStrategy must not be null");
+
+this.namingStrategy = namingStrategy;
+}
+
+NamingStrategy getNamingStrategy() {
+return namingStrategy;
+}
+
 /* (non-Javadoc)
  * @see org.springframework.data.cassandra.core.mapping.CassandraPersistentEntity#getTableName()
  */

spring-data-cassandra/src/main/java/org/springframework/data/cassandra/core/mapping/BasicCassandraPersistentProperty.java

@@ -22,6 +22,8 @@
 import java.lang.reflect.Method;
 import java.util.Map;
 import java.util.Optional;
+import java.util.Set;
+import java.util.function.Supplier;
 
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.ApplicationContextAware;
@@ -62,6 +64,8 @@ public class BasicCassandraPersistentProperty extends AnnotationBasedPersistentP
 
 private @Nullable CqlIdentifier columnName;
 
+private NamingStrategy namingStrategy = NamingStrategy.INSTANCE;
+
 private @Nullable StandardEvaluationContext spelContext;
 
 /**
@@ -180,7 +184,7 @@ private CqlIdentifier determineColumnName() {
 return null;
 }
 
-String defaultName = getName(); // TODO: replace with naming strategy class
+Supplier<String> defaultName = () -> namingStrategy.getColumnName(this);
 String overriddenName = null;
 
 boolean forceQuote = false;
@@ -217,12 +221,15 @@ private CqlIdentifier determineColumnName() {
 }
 
 @Nullable
-private CqlIdentifier createColumnName(String defaultName, @Nullable String overriddenName, boolean forceQuote) {
+private CqlIdentifier createColumnName(Supplier<String> defaultName, @Nullable String overriddenName,
+boolean forceQuote) {
 
-String name = defaultName;
+String name;
 
 if (StringUtils.hasText(overriddenName)) {
 name = this.spelContext != null ? SpelUtils.evaluate(overriddenName, this.spelContext) : overriddenName;
+} else {
+name = defaultName.get();
 }
 
 return name != null ? IdentifierFactory.create(name, forceQuote) : null;
@@ -239,6 +246,19 @@ public void setColumnName(CqlIdentifier columnName) {
 this.columnName = columnName;
 }
 
+/**
+ * Set the {@link NamingStrategy} to use.
+ *
+ * @param namingStrategy must not be {@literal null}.
+ * @since 3.0
+ */
+public void setNamingStrategy(NamingStrategy namingStrategy) {
+
+Assert.notNull(namingStrategy, "NamingStrategy must not be null");
+
+this.namingStrategy = namingStrategy;
+}
+
 /* (non-Javadoc)
  * @see org.springframework.data.cassandra.core.mapping.CassandraPersistentProperty#setForceQuote(boolean)
  */

spring-data-cassandra/src/main/java/org/springframework/data/cassandra/core/mapping/CassandraMappingContext.java

@@ -72,6 +72,8 @@ public class CassandraMappingContext
 
 private Mapping mapping = new Mapping();
 
+private NamingStrategy namingStrategy = NamingStrategy.INSTANCE;
+
 private @Deprecated @Nullable UserTypeResolver userTypeResolver;
 
 private @Deprecated CodecRegistry codecRegistry = CodecRegistry.DEFAULT;
@@ -262,6 +264,19 @@ public CodecRegistry getCodecRegistry() {
 return this.codecRegistry;
 }
 
+/**
+ * Set the {@link NamingStrategy} to use.
+ *
+ * @param namingStrategy must not be {@literal null}.
+ * @since 3.0
+ */
+public void setNamingStrategy(NamingStrategy namingStrategy) {
+
+Assert.notNull(namingStrategy, "NamingStrategy must not be null");
+
+this.namingStrategy = namingStrategy;
+}
+
 /**
  * Sets the {@link TupleTypeFactory}.
  *
@@ -366,6 +381,7 @@ protected <T> BasicCassandraPersistentEntity<T> createPersistentEntity(TypeInfor
 : isTuple(typeInformation) ? new BasicCassandraPersistentTupleEntity<>(typeInformation)
 : new BasicCassandraPersistentEntity<>(typeInformation, getVerifier());
 
+entity.setNamingStrategy(this.namingStrategy);
 Optional.ofNullable(this.applicationContext).ifPresent(entity::setApplicationContext);
 
 return entity;
@@ -390,6 +406,7 @@ protected CassandraPersistentProperty createPersistentProperty(Property property
 ? new BasicCassandraPersistentTupleProperty(property, owner, simpleTypeHolder)
 : new BasicCassandraPersistentProperty(property, owner, simpleTypeHolder);
 
+persistentProperty.setNamingStrategy(this.namingStrategy);
 Optional.ofNullable(this.applicationContext).ifPresent(persistentProperty::setApplicationContext);
 
 return persistentProperty;

spring-data-cassandra/src/main/java/org/springframework/data/cassandra/core/mapping/CassandraUserTypePersistentEntity.java

@@ -53,7 +53,7 @@ protected CqlIdentifier determineTableName() {
 return determineName(annotation.value(), annotation.forceQuote());
 }
 
-return super.determineTableName();
+return IdentifierFactory.create(getNamingStrategy().getUserDefinedTypeName(this), false);
 }
 
 /* (non-Javadoc)

spring-data-cassandra/src/main/java/org/springframework/data/cassandra/core/mapping/NamingStrategy.java

@@ -0,0 +1,94 @@
+/*
+ * Copyright 2017-2020 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.
+ * <p>
+ * 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.
+ * <p>
+ * 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<?> type) {
+
+Assert.notNull(type, "CassandraPersistentEntity must not be null!");
+
+return type.getType().getSimpleName();
+}
+
+/**
+ * Create a user-defined type name from the given {@link CassandraPersistentEntity}.
+ */
+default String getUserDefinedTypeName(CassandraPersistentEntity<?> type) {
+
+Assert.notNull(type, "CassandraPersistentEntity must not be null!");
+
+return type.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:
+ * <p class="code">
+ * NamingStrategy lower = NamingStrategy.INSTANCE.transform(String::toLowerCase);
+ * </p>
+ *
+ * @param mappingFunction must not be {@literal null}.
+ * @return the {@link NamingStrategy} that applies the given {@link UnaryOperator transformation function}.
+ */
+default NamingStrategy transform(UnaryOperator<String> mappingFunction) {
+
+Assert.notNull(mappingFunction, "Mapping function must not be null!");
+
+NamingStrategy previous = this;
+
+return new TransformingNamingStrategy(previous, mappingFunction);
+}
+}

spring-data-cassandra/src/main/java/org/springframework/data/cassandra/core/mapping/SnakeCaseNamingStrategy.java

@@ -0,0 +1,60 @@
+/*
+ * Copyright 2020 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 org.springframework.data.util.ParsingUtils;
+import org.springframework.util.Assert;
+
+/**
+ * Naming strategy that renders CamelCase name parts to {@code snake_case}.
+ *
+ * @author Mark Paluch
+ * @since 3.0
+ */
+public class SnakeCaseNamingStrategy implements NamingStrategy {
+
+public SnakeCaseNamingStrategy() {}
+
+/**
+ * Uses {@link Class#getSimpleName()} and separates camel case parts with '_'.
+ */
+public String getTableName(CassandraPersistentEntity<?> type) {
+
+Assert.notNull(type, "CassandraPersistentEntity must not be null!");
+
+return ParsingUtils.reconcatenateCamelCase(type.getType().getSimpleName(), "_");
+}
+
+/**
+ * Uses {@link Class#getSimpleName()} and separates camel case parts with '_'.
+ */
+public String getUserDefinedTypeName(CassandraPersistentEntity<?> type) {
+
+Assert.notNull(type, "CassandraPersistentEntity must not be null!");
+
+return ParsingUtils.reconcatenateCamelCase(type.getType().getSimpleName(), "_");
+}
+
+/**
+ * Uses {@link CassandraPersistentProperty#getName()} and separates camel case parts with '_'.
+ */
+public String getColumnName(CassandraPersistentProperty property) {
+
+Assert.notNull(property, "CassandraPersistentProperty must not be null.");
+
+return ParsingUtils.reconcatenateCamelCase(property.getName(), "_");
+}
+}