#295 NullValueMapping for BeanMapping on mapping method level

core-common/src/main/java/org/mapstruct/MapNullToDefault.java

@@ -0,0 +1,45 @@
+/**
+ *  Copyright 2012-2014 Gunnar Morling (http://www.gunnarmorling.de/)
+ *  and/or other contributors as indicated by the @authors tag. See the
+ *  copyright.txt file in the distribution for a full listing of all
+ *  contributors.
+ *
+ *  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.mapstruct;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Advises the code generator to apply all the {@link Mapping}s from an inverse mapping method to the annotated method
+ * as well. An inverse mapping method is a method which has the annotated method's source type as target type (return
+ * type or indicated through a parameter annotated with {@link MappingTarget}) and the annotated method's target type as
+ * source type.
+ * <p>
+ * Any mappings given on the annotated method itself are added to those mappings inherited from the inverse method. In
+ * case of a conflict local mappings take precedence over inherited mappings.
+ * <p>
+ * If more than one matching inverse method exists, the name of the method to inherit the configuration from must be
+ * specified via {@link #name()}
+ *
+ * @author Sjaak Derksen
+ */
+@Target( { ElementType.METHOD, ElementType.TYPE } )
+@Retention( RetentionPolicy.SOURCE )
+public @interface MapNullToDefault {
+
+    boolean value() default true;
+}

processor/src/main/java/org/mapstruct/ap/model/BeanMappingMethod.java

@@ -40,6 +40,7 @@ import org.mapstruct.ap.model.source.Mapping;
 import org.mapstruct.ap.model.source.SourceMethod;
 import org.mapstruct.ap.model.source.SourceReference;
 import org.mapstruct.ap.option.ReportingPolicy;
+import org.mapstruct.ap.prism.MapNullToDefaultPrism;
 import org.mapstruct.ap.prism.CollectionMappingStrategyPrism;
 import org.mapstruct.ap.util.Executables;
 import org.mapstruct.ap.util.MapperConfig;
@@ -58,6 +59,7 @@ public class BeanMappingMethod extends MappingMethod {
     private final Map<String, List<PropertyMapping>> mappingsByParameter;
     private final List<PropertyMapping> constantMappings;
     private final MethodReference factoryMethod;
+    private final boolean mapNullToDefault;
 
     public static class Builder {
 
@@ -97,8 +99,12 @@ public class BeanMappingMethod extends MappingMethod {
             // report errors on unmapped properties
             reportErrorForUnmappedTargetPropertiesIfRequired();
 
+            // mapNullToDefault
+            MapNullToDefaultPrism prism = MapNullToDefaultPrism.getInstanceOn( method.getExecutable() );
+            boolean mapNullToDefault = ( prism != null ) && prism.value();
+
             MethodReference factoryMethod = AssignmentFactory.createFactoryMethod( method.getReturnType(), ctx );
-            return new BeanMappingMethod( method, propertyMappings, factoryMethod );
+            return new BeanMappingMethod( method, propertyMappings, factoryMethod, mapNullToDefault );
         }
 
         /**
@@ -472,7 +478,8 @@ public class BeanMappingMethod extends MappingMethod {
 
     private BeanMappingMethod(SourceMethod method,
                               List<PropertyMapping> propertyMappings,
-                              MethodReference factoryMethod) {
+                              MethodReference factoryMethod,
+                              boolean mapNullToDefault ) {
         super( method );
         this.propertyMappings = propertyMappings;
 
@@ -491,6 +498,7 @@ public class BeanMappingMethod extends MappingMethod {
             }
         }
         this.factoryMethod = factoryMethod;
+        this.mapNullToDefault = mapNullToDefault;
     }
 
     public List<PropertyMapping> getPropertyMappings() {
@@ -505,6 +513,10 @@ public class BeanMappingMethod extends MappingMethod {
         return mappingsByParameter;
     }
 
+    public boolean isMapNullToDefault() {
+        return mapNullToDefault;
+    }
+
     @Override
     public Set<Type> getImportTypes() {
         Set<Type> types = super.getImportTypes();

processor/src/main/java/org/mapstruct/ap/prism/PrismGenerator.java

@@ -27,6 +27,7 @@ import org.mapstruct.DecoratedWith;
 import org.mapstruct.InheritInverseConfiguration;
 import org.mapstruct.IterableMapping;
 import org.mapstruct.MapMapping;
+import org.mapstruct.MapNullToDefault;
 import org.mapstruct.Mapper;
 import org.mapstruct.MapperConfig;
 import org.mapstruct.Mapping;
@@ -52,6 +53,7 @@ import org.mapstruct.TargetType;
     @GeneratePrism(value = MapperConfig.class, publicAccess = true),
     @GeneratePrism(value = InheritInverseConfiguration.class, publicAccess = true),
     @GeneratePrism( value = Qualifier.class, publicAccess = true ),
+    @GeneratePrism( value = MapNullToDefault.class, publicAccess = true ),
 
     // external types
     @GeneratePrism(value = XmlElementDecl.class, publicAccess = true)

processor/src/main/resources/org.mapstruct.ap.model.BeanMappingMethod.ftl

@@ -20,9 +20,11 @@
 -->
 @Override
 <#lt>${accessibility.keyword} <@includeModel object=returnType/> ${name}(<#list parameters as param><@includeModel object=param/><#if param_has_next>, </#if></#list>) <@throws/> {
+    <#if !mapNullToDefault>
     if ( <#list sourceParametersExcludingPrimitives as sourceParam>${sourceParam.name} == null<#if sourceParam_has_next> && </#if></#list> ) {
         return<#if returnType.name != "void"> null</#if>;
     }
+    </#if>
 
     <#if !existingInstanceMapping><@includeModel object=resultType/> ${resultName} = <#if factoryMethod??><@includeModel object=factoryMethod targetType=resultType raw=true/><#else>new <@includeModel object=resultType/>()</#if>;</#if>
     <#if (sourceParameters?size > 1)>
@@ -43,9 +45,11 @@
             </#if>
         </#list>
     <#else>
+        <#if mapNullToDefault>if ( ${sourceParameters[0].name} != null ) {</#if>
         <#list propertyMappingsByParameter[sourceParameters[0].name] as propertyMapping>
             <@includeModel object=propertyMapping targetBeanName=resultName existingInstanceMapping=existingInstanceMapping/>
         </#list>
+        <#if mapNullToDefault>}</#if>
     </#if>
     <#list constantMappings as constantMapping>
          <@includeModel object=constantMapping targetBeanName=resultName existingInstanceMapping=existingInstanceMapping/>

processor/src/test/java/org/mapstruct/ap/test/mapnulltodefault/CarMapper.java

@@ -0,0 +1,53 @@
+/**
+ *  Copyright 2012-2014 Gunnar Morling (http://www.gunnarmorling.de/)
+ *  and/or other contributors as indicated by the @authors tag. See the
+ *  copyright.txt file in the distribution for a full listing of all
+ *  contributors.
+ *
+ *  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.mapstruct.ap.test.mapnulltodefault;
+
+import java.util.UUID;
+
+import org.mapstruct.Mapper;
+import org.mapstruct.MapNullToDefault;
+import org.mapstruct.Mapping;
+import org.mapstruct.Mappings;
+import org.mapstruct.ap.test.mapnulltodefault.source.Car;
+import org.mapstruct.ap.test.mapnulltodefault.target.CarDto;
+import org.mapstruct.factory.Mappers;
+
+@Mapper(imports = UUID.class)
+public interface CarMapper {
+
+    CarMapper INSTANCE = Mappers.getMapper( CarMapper.class );
+
+    @MapNullToDefault
+    @Mappings({
+        @Mapping(target = "seatCount", source = "numberOfSeats"),
+        @Mapping(target = "model", constant = "ModelT"),
+        @Mapping(target = "catalogId", expression = "java( UUID.randomUUID().toString() )")
+    })
+    CarDto carToCarDto(Car car);
+
+    @MapNullToDefault
+    @Mappings({
+        @Mapping(target = "seatCount", source = "car.numberOfSeats"),
+        @Mapping(target = "model", source = "model"), // TODO,  should not be needed, must be made based on name only
+        @Mapping(target = "catalogId", expression = "java( UUID.randomUUID().toString() )")
+    })
+    CarDto carToCarDto(Car car, String model);
+
+
+}

processor/src/test/java/org/mapstruct/ap/test/mapnulltodefault/CarMapperTest.java

@@ -0,0 +1,95 @@
+/**
+ *  Copyright 2012-2014 Gunnar Morling (http://www.gunnarmorling.de/)
+ *  and/or other contributors as indicated by the @authors tag. See the
+ *  copyright.txt file in the distribution for a full listing of all
+ *  contributors.
+ *
+ *  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.mapstruct.ap.test.mapnulltodefault;
+
+import static org.fest.assertions.Assertions.assertThat;
+
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mapstruct.ap.test.mapnulltodefault.source.Car;
+import org.mapstruct.ap.test.mapnulltodefault.target.CarDto;
+import org.mapstruct.ap.testutil.WithClasses;
+import org.mapstruct.ap.testutil.runner.AnnotationProcessorTestRunner;
+
+@WithClasses({
+    Car.class,
+    CarDto.class,
+    CarMapper.class
+})
+@RunWith(AnnotationProcessorTestRunner.class)
+public class CarMapperTest {
+
+    @Test
+    public void shouldProvideMapperInstance() throws Exception {
+        assertThat( CarMapper.INSTANCE ).isNotNull();
+    }
+
+    @Test
+    public void shouldMapExpressionAndConstantRegardlessNullArg() {
+        //given
+        Car car = new Car( "Morris", 2 );
+
+        //when
+        CarDto carDto1 = CarMapper.INSTANCE.carToCarDto( car );
+
+        //then
+        assertThat( carDto1 ).isNotNull();
+        assertThat( carDto1.getMake() ).isEqualTo( car.getMake() );
+        assertThat( carDto1.getSeatCount() ).isEqualTo( car.getNumberOfSeats() );
+        assertThat( carDto1.getModel() ).isEqualTo( "ModelT" );
+        assertThat( carDto1.getCatalogId() ).isNotEmpty();
+
+        //when
+        CarDto carDto2 = CarMapper.INSTANCE.carToCarDto( null );
+
+        //then
+        assertThat( carDto2 ).isNotNull();
+        assertThat( carDto2.getMake() ).isNull();
+        assertThat( carDto2.getSeatCount() ).isEqualTo( 0 );
+        assertThat( carDto2.getModel() ).isEqualTo( "ModelT" );
+        assertThat( carDto2.getCatalogId() ).isNotEmpty();
+    }
+
+   @Test
+    public void shouldMapExpressionAndConstantRegardlessNullArgSeveralSources() {
+        //given
+        Car car = new Car( "Morris", 2 );
+
+        //when
+        CarDto carDto1 = CarMapper.INSTANCE.carToCarDto( car, "ModelT" );
+
+        //then
+        assertThat( carDto1 ).isNotNull();
+        assertThat( carDto1.getMake() ).isEqualTo( car.getMake() );
+        assertThat( carDto1.getSeatCount() ).isEqualTo( car.getNumberOfSeats() );
+        assertThat( carDto1.getCatalogId() ).isNotEmpty();
+
+        //when
+        CarDto carDto2 = CarMapper.INSTANCE.carToCarDto( null, "ModelT" );
+
+        //then
+        assertThat( carDto2 ).isNotNull();
+        assertThat( carDto2.getMake() ).isNull();
+        assertThat( carDto2.getSeatCount() ).isEqualTo( 0 );
+        assertThat( carDto2.getModel() ).isEqualTo( "ModelT" );
+        assertThat( carDto2.getCatalogId() ).isNotEmpty();
+    }
+
+}

processor/src/test/java/org/mapstruct/ap/test/mapnulltodefault/source/Car.java

@@ -0,0 +1,53 @@
+/**
+ *  Copyright 2012-2014 Gunnar Morling (http://www.gunnarmorling.de/)
+ *  and/or other contributors as indicated by the @authors tag. See the
+ *  copyright.txt file in the distribution for a full listing of all
+ *  contributors.
+ *
+ *  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.mapstruct.ap.test.mapnulltodefault.source;
+
+
+public class Car {
+
+    private String make;
+    private int numberOfSeats;
+
+
+    public Car() {
+    }
+
+    public Car(String make, int numberOfSeats) {
+        this.make = make;
+        this.numberOfSeats = numberOfSeats;
+
+    }
+
+    public String getMake() {
+        return make;
+    }
+
+    public void setMake(String make) {
+        this.make = make;
+    }
+
+    public int getNumberOfSeats() {
+        return numberOfSeats;
+    }
+
+    public void setNumberOfSeats(int numberOfSeats) {
+        this.numberOfSeats = numberOfSeats;
+    }
+
+}

processor/src/test/java/org/mapstruct/ap/test/mapnulltodefault/target/CarDto.java

@@ -0,0 +1,69 @@
+/**
+ *  Copyright 2012-2014 Gunnar Morling (http://www.gunnarmorling.de/)
+ *  and/or other contributors as indicated by the @authors tag. See the
+ *  copyright.txt file in the distribution for a full listing of all
+ *  contributors.
+ *
+ *  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.mapstruct.ap.test.mapnulltodefault.target;
+
+public class CarDto {
+
+    private String make;
+    private int seatCount;
+    private String model;
+    private String catalogId;
+
+
+    public CarDto() {
+    }
+
+    public CarDto(String make, int seatCount) {
+        this.make = make;
+        this.seatCount = seatCount;
+    }
+
+    public String getMake() {
+        return make;
+    }
+
+    public void setMake(String make) {
+        this.make = make;
+    }
+
+    public int getSeatCount() {
+        return seatCount;
+    }
+
+    public void setSeatCount(int seatCount) {
+        this.seatCount = seatCount;
+    }
+
+    public String getModel() {
+        return model;
+    }
+
+    public void setModel( String model ) {
+        this.model = model;
+    }
+
+    public String getCatalogId() {
+        return catalogId;
+    }
+
+    public void setCatalogId( String catalogId ) {
+        this.catalogId = catalogId;
+    }
+
+}