DATACMNS-523 - Pulled up FieldNamingStrategy SPI from Spring Data MongoDB.

Pulled up the SPI for field naming from Spring Data MongoDB for reuse in other Spring Data modules.

src/main/java/org/springframework/data/mapping/model/CamelCaseAbbreviatingFieldNamingStrategy.java

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2013-2014 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
+ *
+ *      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.springframework.data.mapping.model;
+
+/**
+ * {@link FieldNamingStrategy} that abbreviates field names by using the very first letter of the camel case parts of
+ * the {@link MongoPersistentProperty}'s name.
+ * 
+ * @since 1.9
+ * @author Oliver Gierke
+ */
+public class CamelCaseAbbreviatingFieldNamingStrategy extends CamelCaseSplittingFieldNamingStrategy {
+
+	/**
+	 * Creates a new {@link CamelCaseAbbreviatingFieldNamingStrategy}.
+	 */
+	public CamelCaseAbbreviatingFieldNamingStrategy() {
+		super("");
+	}
+
+	/* 
+	 * (non-Javadoc)
+	 * @see org.springframework.data.mongodb.core.mapping.CamelCaseSplittingFieldNamingStrategy#preparePart(java.lang.String)
+	 */
+	@Override
+	protected String preparePart(String part) {
+		return part.substring(0, 1);
+	}
+}

src/main/java/org/springframework/data/mapping/model/CamelCaseSplittingFieldNamingStrategy.java

@@ -0,0 +1,80 @@
+/*
+ * Copyright 2014 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
+ *
+ *      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.springframework.data.mapping.model;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.springframework.data.mapping.PersistentProperty;
+import org.springframework.data.util.ParsingUtils;
+import org.springframework.util.Assert;
+import org.springframework.util.StringUtils;
+
+/**
+ * Configurable {@link FieldNamingStrategy} that splits up camel-case property names and reconcatenates them using a
+ * configured delimiter. Individual parts of the name can be manipulated using {@link #preparePart(String)}.
+ * 
+ * @author Oliver Gierke
+ * @since 1.9
+ */
+public class CamelCaseSplittingFieldNamingStrategy implements FieldNamingStrategy {
+
+	private final String delimiter;
+
+	/**
+	 * Creates a new {@link CamelCaseSplittingFieldNamingStrategy}.
+	 * 
+	 * @param delimiter must not be {@literal null}.
+	 */
+	public CamelCaseSplittingFieldNamingStrategy(String delimiter) {
+
+		Assert.notNull(delimiter, "Delimiter must not be null!");
+		this.delimiter = delimiter;
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.mapping.model.FieldNamingStrategy#getFieldName(org.springframework.data.mapping.PersistentProperty)
+	 */
+	@Override
+	public String getFieldName(PersistentProperty<?> property) {
+
+		List<String> parts = ParsingUtils.splitCamelCaseToLower(property.getName());
+		List<String> result = new ArrayList<String>();
+
+		for (String part : parts) {
+
+			String candidate = preparePart(part);
+
+			if (StringUtils.hasText(candidate)) {
+				result.add(candidate);
+			}
+		}
+
+		return StringUtils.collectionToDelimitedString(result, delimiter);
+	}
+
+	/**
+	 * Callback to prepare the uncapitalized part obtained from the split up of the camel case source. Default
+	 * implementation returns the part as is.
+	 * 
+	 * @param part
+	 * @return
+	 */
+	protected String preparePart(String part) {
+		return part;
+	}
+}

src/main/java/org/springframework/data/mapping/model/FieldNamingStrategy.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright 2013-2014 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
+ *
+ *      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.springframework.data.mapping.model;
+
+import org.springframework.data.mapping.PersistentProperty;
+
+/**
+ * SPI to determine how to name document fields in cases the field name is not manually defined.
+ * 
+ * @see PropertyNameFieldNamingStrategy
+ * @see CamelCaseAbbreviatingFieldNamingStrategy
+ * @see SnakeCaseFieldNamingStrategy
+ * @since 1.9
+ * @author Oliver Gierke
+ */
+public interface FieldNamingStrategy {
+
+	/**
+	 * Returns the field name to be used for the given {@link MongoPersistentProperty}.
+	 * 
+	 * @param property must not be {@literal null} or empty;
+	 * @return
+	 */
+	String getFieldName(PersistentProperty<?> property);
+}

src/main/java/org/springframework/data/mapping/model/PropertyNameFieldNamingStrategy.java

@@ -0,0 +1,37 @@
+/*
+ * Copyright 2013-2014 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
+ *
+ *      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.springframework.data.mapping.model;
+
+import org.springframework.data.mapping.PersistentProperty;
+
+/**
+ * {@link FieldNamingStrategy} simply using the {@link MongoPersistentProperty}'s name.
+ * 
+ * @since 1.9
+ * @author Oliver Gierke
+ */
+public enum PropertyNameFieldNamingStrategy implements FieldNamingStrategy {
+
+	INSTANCE;
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.mapping.model.FieldNamingStrategy#getFieldName(org.springframework.data.mapping.PersistentProperty)
+	 */
+	public String getFieldName(PersistentProperty<?> property) {
+		return property.getName();
+	}
+}

src/main/java/org/springframework/data/mapping/model/SnakeCaseFieldNamingStrategy.java

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2013-2014 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
+ *
+ *      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.springframework.data.mapping.model;
+
+/**
+ * {@link FieldNamingStrategy} that translates typical camel case Java property names to lower case JSON element names,
+ * separated by underscores.
+ * 
+ * @since 1.5
+ * @author Ryan Tenney
+ * @author Oliver Gierke
+ */
+public class SnakeCaseFieldNamingStrategy extends CamelCaseSplittingFieldNamingStrategy {
+
+	/**
+	 * Creates a new {@link SnakeCaseFieldNamingStrategy}.
+	 */
+	public SnakeCaseFieldNamingStrategy() {
+		super("_");
+	}
+}

src/test/java/org/springframework/data/mapping/model/CamelCaseAbbreviatingFieldNamingStrategyUnitTests.java

@@ -0,0 +1,56 @@
+/*
+ * Copyright 2013-2014 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
+ *
+ *      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.springframework.data.mapping.model;
+
+import static org.hamcrest.CoreMatchers.*;
+import static org.junit.Assert.*;
+import static org.mockito.Mockito.*;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.runners.MockitoJUnitRunner;
+import org.springframework.data.mapping.PersistentProperty;
+
+/**
+ * Unit tests for {@link CamelCaseAbbreviatingFieldNamingStrategy}.
+ * 
+ * @author Oliver Gierke
+ * @since 1.9
+ */
+@RunWith(MockitoJUnitRunner.class)
+public class CamelCaseAbbreviatingFieldNamingStrategyUnitTests {
+
+	FieldNamingStrategy strategy = new CamelCaseAbbreviatingFieldNamingStrategy();
+
+	@Mock PersistentProperty<?> property;
+
+	/**
+	 * @see DATACMNS-523
+	 */
+	@Test
+	public void abbreviatesToCamelCase() {
+
+		assertFieldNameForPropertyName("fooBar", "fb");
+		assertFieldNameForPropertyName("fooBARFooBar", "fbfb");
+	}
+
+	private void assertFieldNameForPropertyName(String propertyName, String fieldName) {
+
+		when(property.getName()).thenReturn(propertyName);
+		assertThat(strategy.getFieldName(property), is(fieldName));
+	}
+}

src/test/java/org/springframework/data/mapping/model/SnakeCaseFieldNamingStrategyUnitTests.java

@@ -0,0 +1,59 @@
+/*
+ * Copyright 2013-2014 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
+ *
+ *      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.springframework.data.mapping.model;
+
+import static org.hamcrest.CoreMatchers.*;
+import static org.junit.Assert.*;
+import static org.mockito.Mockito.*;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.runners.MockitoJUnitRunner;
+import org.springframework.data.mapping.PersistentProperty;
+
+/**
+ * Unit tests for {@link SnakeCaseFieldNamingStrategy}.
+ * 
+ * @author Ryan Tenney
+ * @author Oliver Gierke
+ * @since 1.9
+ */
+@RunWith(MockitoJUnitRunner.class)
+public class SnakeCaseFieldNamingStrategyUnitTests {
+
+	FieldNamingStrategy strategy = new SnakeCaseFieldNamingStrategy();
+
+	@Mock PersistentProperty<?> property;
+
+	/**
+	 * @see DATACMNS-523
+	 */
+	@Test
+	public void rendersSnakeCaseFieldNames() {
+
+		assertFieldNameForPropertyName("fooBar", "foo_bar");
+		assertFieldNameForPropertyName("FooBar", "foo_bar");
+		assertFieldNameForPropertyName("foo_bar", "foo_bar");
+		assertFieldNameForPropertyName("FOO_BAR", "foo_bar");
+	}
+
+	private void assertFieldNameForPropertyName(String propertyName, String fieldName) {
+
+		when(property.getName()).thenReturn(propertyName);
+		assertThat(strategy.getFieldName(property), is(fieldName));
+	}
+}