#827 - ENH: Add support for AttributeConverter from JPA 2.1

src/main/java/com/avaje/ebeaninternal/server/core/bootup/BootupClasses.java

@@ -22,6 +22,7 @@ import org.avaje.classpath.scanner.ClassFilter;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import javax.persistence.AttributeConverter;
 import javax.persistence.Embeddable;
 import javax.persistence.Entity;
 import javax.persistence.Table;
@@ -47,12 +48,14 @@ public class BootupClasses implements ClassFilter {
 
   private final List<Class<? extends ScalarTypeConverter<?, ?>>> scalarConverterList = new ArrayList<>();
 
+  private final List<Class<? extends AttributeConverter<?, ?>>> attributeConverterList = new ArrayList<>();
+
   private final List<Class<? extends CompoundType<?>>> compoundTypeList = new ArrayList<>();
 
 
-  // The following objects are instantiiated on first request
+  // The following objects are instantiated on first request
   // there is always a candidate list, that holds the class and an
-  // instance list, that holds the instance. Once a class is instantiiated
+  // instance list, that holds the instance. Once a class is instantiated
   // (or added) it will get removed from the candidate list
   private final List<Class<? extends IdGenerator>> idGeneratorCandidates = new ArrayList<>();
 
@@ -337,6 +340,13 @@ public class BootupClasses implements ClassFilter {
     return scalarConverterList;
   }
 
+  /**
+   * Return the list of AttributeConverters found.
+   */
+  public List<Class<? extends AttributeConverter<?, ?>>> getAttributeConverters() {
+    return attributeConverterList;
+  }
+
   /**
    * Return the list of ScalarConverters found.
    */
@@ -387,6 +397,11 @@ public class BootupClasses implements ClassFilter {
       interesting = true;
     }
 
+    if (AttributeConverter.class.isAssignableFrom(cls)) {
+      attributeConverterList.add((Class<? extends AttributeConverter<?, ?>>) cls);
+      interesting = true;
+    }
+
     if (CompoundType.class.isAssignableFrom(cls)) {
       compoundTypeList.add((Class<? extends CompoundType<?>>) cls);
       interesting = true;

src/main/java/com/avaje/ebeaninternal/server/type/AttributeConverterAdapter.java

@@ -0,0 +1,32 @@
+package com.avaje.ebeaninternal.server.type;
+
+import com.avaje.ebean.config.ScalarTypeConverter;
+
+import javax.persistence.AttributeConverter;
+
+/**
+ * Adapter from ScalarTypeConverter to AttributeConverter.
+ */
+class AttributeConverterAdapter<B,S> implements ScalarTypeConverter<B, S> {
+
+  private final AttributeConverter<B,S> converter;
+
+  AttributeConverterAdapter(AttributeConverter<B, S> converter) {
+    this.converter = converter;
+  }
+
+  @Override
+  public B getNullValue() {
+    return null;
+  }
+
+  @Override
+  public B wrapValue(S dbValue) {
+    return converter.convertToEntityAttribute(dbValue);
+  }
+
+  @Override
+  public S unwrapValue(B beanType) {
+    return converter.convertToDatabaseColumn(beanType);
+  }
+}

src/main/java/com/avaje/ebeaninternal/server/type/DefaultTypeManager.java

@@ -34,6 +34,7 @@ import org.joda.time.LocalTime;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import javax.persistence.AttributeConverter;
 import java.io.File;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.Field;
@@ -223,6 +224,7 @@ public final class DefaultTypeManager implements TypeManager, KnownImmutable {
     if (bootupClasses != null) {
       initialiseCustomScalarTypes(jsonDateTime, bootupClasses);
       initialiseScalarConverters(bootupClasses);
+      initialiseAttributeConverters(bootupClasses);
       initialiseCompoundTypes(bootupClasses);
     }
   }
@@ -813,17 +815,46 @@ public final class DefaultTypeManager implements TypeManager, KnownImmutable {
 
         ScalarTypeConverter converter = (ScalarTypeConverter) cls.newInstance();
         ScalarTypeWrapper stw = new ScalarTypeWrapper(logicalType, wrappedType, converter);
-
         logger.debug("Register ScalarTypeWrapper from " + logicalType + " -> " + persistType + " using:" + cls);
-
         add(stw);
 
       } catch (Exception e) {
-        String msg = "Error loading ScalarType [" + cls.getName() + "]";
-        logger.error(msg, e);
+        logger.error("Error registering ScalarTypeConverter [" + cls.getName() + "]", e);
       }
     }
+  }
 
+  @SuppressWarnings({"unchecked", "rawtypes"})
+  private void initialiseAttributeConverters(BootupClasses bootupClasses) {
+
+    List<Class<? extends AttributeConverter<?, ?>>> foundTypes = bootupClasses.getAttributeConverters();
+
+    for (Class<? extends AttributeConverter<?, ?>> foundType : foundTypes) {
+      Class<?> cls = foundType;
+      try {
+
+        Class<?>[] paramTypes = TypeReflectHelper.getParams(cls, AttributeConverter.class);
+        if (paramTypes.length != 2) {
+          throw new IllegalStateException("Expected 2 generics paramtypes but got: " + Arrays.toString(paramTypes));
+        }
+
+        Class<?> logicalType = paramTypes[0];
+        Class<?> persistType = paramTypes[1];
+
+        ScalarType<?> wrappedType = getScalarType(persistType);
+        if (wrappedType == null) {
+          throw new IllegalStateException("Could not find ScalarType for: " + paramTypes[1]);
+        }
+
+        AttributeConverter converter = (AttributeConverter) cls.newInstance();
+        ScalarTypeWrapper stw = new ScalarTypeWrapper(logicalType, wrappedType, new AttributeConverterAdapter(converter));
+        logger.debug("Register ScalarTypeWrapper from " + logicalType + " -> " + persistType + " using:" + cls);
+        add(stw);
+
+      } catch (Exception e) {
+        logger.error("Error registering AttributeConverter [" + cls.getName() + "]", e);
+      }
+    }
   }
 
   private void initialiseCompoundTypes(BootupClasses bootupClasses) {

src/test/java/com/avaje/tests/model/ivo/ESomeConvertType.java

@@ -0,0 +1,44 @@
+package com.avaje.tests.model.ivo;
+
+import javax.persistence.Entity;
+import javax.persistence.Id;
+
+@Entity
+public class ESomeConvertType {
+
+  @Id
+  Long id;
+
+  String name;
+
+  Rate rate;
+
+  public ESomeConvertType(String name, Rate rate) {
+    this.name = name;
+    this.rate = rate;
+  }
+
+  public Long getId() {
+    return id;
+  }
+
+  public void setId(Long id) {
+    this.id = id;
+  }
+
+  public String getName() {
+    return name;
+  }
+
+  public void setName(String name) {
+    this.name = name;
+  }
+
+  public Rate getRate() {
+    return rate;
+  }
+
+  public void setRate(Rate rate) {
+    this.rate = rate;
+  }
+}

src/test/java/com/avaje/tests/model/ivo/converter/RateTypeConverter.java

@@ -2,19 +2,23 @@ package com.avaje.tests.model.ivo.converter;
 
 import com.avaje.tests.model.ivo.Rate;
 
+import javax.persistence.AttributeConverter;
+import javax.persistence.Converter;
 import java.math.BigDecimal;
 
 /**
  * Converts between Rate and BigDecimal.
  */
-public class RateTypeConverter {//implements ScalarTypeConverter<Rate,BigDecimal>{
+@Converter
+public class RateTypeConverter implements AttributeConverter<Rate,BigDecimal> {
 
-  public BigDecimal unwrapValue(Rate beanType) {
-    return beanType.getValue();
+  @Override
+  public BigDecimal convertToDatabaseColumn(Rate attribute) {
+    return attribute.getValue();
   }
 
-  public Rate wrapValue(BigDecimal scalarType) {
-    return new Rate(scalarType);
+  @Override
+  public Rate convertToEntityAttribute(BigDecimal dbData) {
+    return new Rate(dbData);
   }
-
 }

src/test/java/com/avaje/tests/model/ivo/test/TestAttributeConverter.java

@@ -0,0 +1,24 @@
+package com.avaje.tests.model.ivo.test;
+
+import com.avaje.ebean.BaseTestCase;
+import com.avaje.ebean.Ebean;
+import com.avaje.tests.model.ivo.ESomeConvertType;
+import com.avaje.tests.model.ivo.Rate;
+import org.junit.Test;
+
+public class TestAttributeConverter extends BaseTestCase {
+
+  @Test
+  public void insertUpdateDelete() {
+
+    ESomeConvertType bean = new ESomeConvertType("one", new Rate(20.1));
+
+    Ebean.save(bean);
+
+    ESomeConvertType found = Ebean.find(ESomeConvertType.class, bean.getId());
+    found.setRate(new Rate("40"));
+    Ebean.save(found);
+
+    Ebean.delete(found);
+  }
+}