DATAGRAPH-488 - Add Enum <-> Number converter

spring-data-neo4j/src/main/java/org/springframework/data/neo4j/fieldaccess/Neo4jConversionServiceFactoryBean.java

@@ -27,6 +27,7 @@ import org.springframework.data.geo.Point;
 import org.springframework.data.geo.Shape;
 import org.springframework.data.neo4j.repository.GeoConverter;
 
+import java.util.Arrays;
 import java.util.Date;
 
 public class Neo4jConversionServiceFactoryBean implements FactoryBean<ConversionService> {
@@ -47,11 +48,13 @@ public class Neo4jConversionServiceFactoryBean implements FactoryBean<Conversion
             registry.addConverter(new StringToDateConverter());
             registry.addConverter(new NumberToDateConverter());
             registry.addConverter(new EnumToStringConverter());
+            registry.addConverter(new EnumToIntegerConverter());
             registry.addConverter(new ShapeToStringConverter());
             registry.addConverter(new StringToShapeConverter());
             registry.addConverter(new PointToStringConverter());
             registry.addConverter(new StringToPointConverter());
             registry.addConverterFactory(new StringToEnumConverterFactory());
+            registry.addConverterFactory(new NumberToEnumConverterFactory());
         } else {
             throw new IllegalArgumentException("conversionservice is no ConverterRegistry:" + service);
         }
@@ -105,6 +108,13 @@ public class Neo4jConversionServiceFactoryBean implements FactoryBean<Conversion
             return source.name();
         }
     }
+    public static class EnumToIntegerConverter implements Converter<Enum, Integer> {
+
+        @Override
+        public Integer convert(Enum source) {
+            return source.ordinal();
+        }
+    }
 
     public static class ShapeToStringConverter implements Converter<Shape, String> {
 
@@ -163,4 +173,30 @@ public class Neo4jConversionServiceFactoryBean implements FactoryBean<Conversion
         }
 
     }
+    public static class NumberToEnumConverterFactory implements ConverterFactory<Number, Enum> {
+
+        @SuppressWarnings("unchecked")
+        public <T extends Enum> Converter<Number, T> getConverter(Class<T> targetType) {
+            return new NumberToEnum(targetType);
+        }
+
+        private static class NumberToEnum<T extends Enum> implements Converter<Number, T> {
+
+            private final Class<T> enumType;
+
+            public NumberToEnum(Class<T> enumType) {
+                this.enumType = enumType;
+            }
+
+            @SuppressWarnings("RedundantCast")
+            public T convert(Number source) {
+                if (source == null) return null;
+                T[] values = this.enumType.getEnumConstants();
+                int ordinal = source.intValue();
+                if (ordinal < 0 || ordinal >= values.length) throw new IllegalArgumentException("Ordinal value for Enum out of range "+ordinal+" "+ Arrays.toString(values));
+                return (T)values[ordinal];
+            }
+
+        }
+    }
 }

spring-data-neo4j/src/test/java/org/springframework/data/neo4j/conversion/EnumConverterTests.java

@@ -0,0 +1,92 @@
+package org.springframework.data.neo4j.conversion;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.neo4j.graphdb.GraphDatabaseService;
+import org.neo4j.graphdb.PropertyContainer;
+import org.neo4j.test.TestGraphDatabaseFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.data.neo4j.annotation.GraphId;
+import org.springframework.data.neo4j.annotation.GraphProperty;
+import org.springframework.data.neo4j.annotation.Indexed;
+import org.springframework.data.neo4j.annotation.NodeEntity;
+import org.springframework.data.neo4j.config.EnableNeo4jRepositories;
+import org.springframework.data.neo4j.config.Neo4jConfiguration;
+import org.springframework.data.neo4j.support.Neo4jTemplate;
+import org.springframework.data.neo4j.support.index.IndexType;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+import org.springframework.transaction.annotation.Transactional;
+
+import static org.junit.Assert.assertEquals;
+
+/**
+ * @author mh
+ * @since 30.06.14
+ */
+
+@RunWith(SpringJUnit4ClassRunner.class)
+@ContextConfiguration
+public class EnumConverterTests {
+
+    @Configuration
+    @EnableNeo4jRepositories
+    static class TestConfig extends Neo4jConfiguration {
+        TestConfig() {
+            setBasePackage("org.springframework.data.neo4j.conversion");
+        }
+
+        @Bean
+        GraphDatabaseService graphDatabaseService() {
+            return new TestGraphDatabaseFactory().newImpermanentDatabase();
+        }
+    }
+
+    @Autowired
+    Neo4jTemplate template;
+
+    static enum Letter {
+        A, B, C
+    }
+    static enum Vowel {
+        A, E, I, O, U
+    }
+    static enum Consonant {
+        B,C,D,F,G,H
+    }
+
+    @NodeEntity
+    static class Word {
+        @GraphId
+        Long id;
+        @Indexed(unique = true, indexType = IndexType.LABEL)
+        Letter letter;
+        @GraphProperty(propertyType = String.class)
+        Vowel vowel;
+        @GraphProperty(propertyType = Integer.class)
+        Consonant consonant;
+
+        Word() { }
+
+        Word(Letter letter, Vowel vowel, Consonant consonant) {
+            this.letter = letter;
+            this.vowel = vowel;
+            this.consonant = consonant;
+        }
+    }
+
+    @Test
+    @Transactional
+    public void testConvertEnumsAccordingToAnnotation() throws Exception {
+        Word word = template.save(new Word(Letter.C, Vowel.A, Consonant.B));
+        assertEquals(Letter.C, word.letter);
+        assertEquals(Vowel.A, word.vowel);
+        assertEquals(Consonant.B, word.consonant);
+        PropertyContainer node = template.getPersistentState(word);
+        assertEquals(Letter.C.name(),node.getProperty("letter"));
+        assertEquals(Vowel.A.name(),node.getProperty("vowel"));
+        assertEquals(Consonant.B.ordinal(),node.getProperty("consonant"));
+    }
+}