#6 Using default implementations for mapping collection types

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

@@ -15,9 +15,14 @@
  */
 package org.mapstruct.ap.model;
 
+import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.HashSet;
+import java.util.List;
 import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
 
 /**
  * Represents the type of a bean property, parameter etc.
@@ -30,10 +35,19 @@ public class Type {
         Arrays.asList( "boolean", "char", "byte", "short", "int", "long", "float", "double" )
     );
 
+    private final static ConcurrentMap<String, Type> defaultCollectionImplementationTypes = new ConcurrentHashMap<String, Type>();
+
+    static {
+        defaultCollectionImplementationTypes.put( List.class.getName(), forClass( ArrayList.class ) );
+        defaultCollectionImplementationTypes.put( Set.class.getName(), forClass( HashSet.class ) );
+        defaultCollectionImplementationTypes.put( Collection.class.getName(), forClass( ArrayList.class ) );
+    }
+
     private final String packageName;
     private final String name;
     private final Type elementType;
     private final boolean isEnumType;
+    private final Type implementingType;
 
     public static Type forClass(Class<?> clazz) {
         Package pakkage = clazz.getPackage();
@@ -50,15 +64,12 @@ public class Type {
         this( null, name, null, false );
     }
 
-    public Type(String packageName, String name) {
-        this( packageName, name, null, false );
-    }
-
     public Type(String packageName, String name, Type elementType, boolean isEnumType) {
         this.packageName = packageName;
         this.name = name;
         this.elementType = elementType;
         this.isEnumType = isEnumType;
+        implementingType = defaultCollectionImplementationTypes.get( packageName + "." + name );
     }
 
     public String getPackageName() {
@@ -81,6 +92,10 @@ public class Type {
         return isEnumType;
     }
 
+    public Type getImplementingType() {
+        return implementingType;
+    }
+
     @Override
     public String toString() {
         if ( packageName == null ) {

processor/src/main/resources/mapper-implementation.ftl

@@ -18,7 +18,10 @@
 package ${packageName};
 
 import java.util.ArrayList;
+import java.util.Collection;
+import java.util.HashSet;
 import java.util.List;
+import java.util.Set;
 import javax.annotation.Generated;
 import java.util.Date;
 
@@ -41,7 +44,7 @@ public class ${implementationName} implements ${interfaceName} {
             return null;
         }
 
-        ${beanMapping.targetType.name}<${beanMapping.targetType.elementType.name}> ${beanMapping.targetType.name?uncap_first} = new ${beanMapping.targetType.name}<${beanMapping.targetType.elementType.name}>();
+        ${beanMapping.targetType.name}<${beanMapping.targetType.elementType.name}> ${beanMapping.targetType.name?uncap_first} = new <#if beanMapping.targetType.implementingType??>${beanMapping.targetType.implementingType.name}<#else>${beanMapping.targetType.name}</#if><${beanMapping.targetType.elementType.name}>();
         
         for ( ${beanMapping.sourceType.elementType.name} ${beanMapping.sourceType.elementType.name?uncap_first} : ${beanMapping.mappingMethod.parameterName} ) {
             ${beanMapping.targetType.name?uncap_first}.add( ${beanMapping.mappingMethod.elementMappingMethod.name}( ${beanMapping.sourceType.elementType.name?uncap_first} ) );
@@ -90,7 +93,7 @@ public class ${implementationName} implements ${interfaceName} {
             return null;
         }
 
-        ${beanMapping.sourceType.name}<${beanMapping.sourceType.elementType.name}> ${beanMapping.sourceType.name?uncap_first} = new ${beanMapping.sourceType.name}<${beanMapping.sourceType.elementType.name}>();
+        ${beanMapping.sourceType.name}<${beanMapping.sourceType.elementType.name}> ${beanMapping.sourceType.name?uncap_first} = new <#if beanMapping.sourceType.implementingType??>${beanMapping.sourceType.implementingType.name}<#else>${beanMapping.sourceType.name}</#if><${beanMapping.sourceType.elementType.name}>();
         
         for ( ${beanMapping.targetType.elementType.name} ${beanMapping.targetType.elementType.name?uncap_first} : ${beanMapping.reverseMappingMethod.parameterName} ) {
             ${beanMapping.sourceType.name?uncap_first}.add( ${beanMapping.reverseMappingMethod.elementMappingMethod.name}( ${beanMapping.targetType.elementType.name?uncap_first} ) );

processor/src/test/java/org/mapstruct/ap/test/collection/defaultimplementation/DefaultCollectionImplementationTest.java

@@ -0,0 +1,73 @@
+/**
+ *  Copyright 2012-2013 Gunnar Morling (http://www.gunnarmorling.de/)
+ *
+ *  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.collection.defaultimplementation;
+
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.List;
+
+import org.mapstruct.ap.testutil.IssueKey;
+import org.mapstruct.ap.testutil.MapperTestBase;
+import org.testng.annotations.Test;
+
+import static org.fest.assertions.Assertions.assertThat;
+
+public class DefaultCollectionImplementationTest extends MapperTestBase {
+
+    @Override
+    protected List<Class<?>> getTestClasses() {
+        return Arrays.<Class<?>>asList(
+            Source.class,
+            SourceFoo.class,
+            Target.class,
+            TargetFoo.class,
+            SourceTargetMapper.class
+        );
+    }
+
+    @Test
+    @IssueKey("6")
+    public void shouldUseDefaultImplementationForList() {
+        Source source = new Source();
+        source.setFooList( Arrays.asList( new SourceFoo( "Bob" ), new SourceFoo( "Alice" ) ) );
+        Target target = SourceTargetMapper.INSTANCE.sourceToTarget( source );
+
+        assertThat( target ).isNotNull();
+        assertThat( target.getFooList() ).containsExactly( new TargetFoo( "Bob" ), new TargetFoo( "Alice" ) );
+    }
+
+    @Test
+    @IssueKey("6")
+    public void shouldUseDefaultImplementationForSet() {
+        Source source = new Source();
+        source.setFooSet( new HashSet<SourceFoo>( Arrays.asList( new SourceFoo( "Bob" ), new SourceFoo( "Alice" ) ) ) );
+        Target target = SourceTargetMapper.INSTANCE.sourceToTarget( source );
+
+        assertThat( target ).isNotNull();
+        assertThat( target.getFooSet() ).containsOnly( new TargetFoo( "Bob" ), new TargetFoo( "Alice" ) );
+    }
+
+    @Test
+    @IssueKey("6")
+    public void shouldUseDefaultImplementationForCollection() {
+        Source source = new Source();
+        source.setFooCollection( Arrays.asList( new SourceFoo( "Bob" ), new SourceFoo( "Alice" ) ) );
+        Target target = SourceTargetMapper.INSTANCE.sourceToTarget( source );
+
+        assertThat( target ).isNotNull();
+        assertThat( target.getFooCollection() ).containsOnly( new TargetFoo( "Bob" ), new TargetFoo( "Alice" ) );
+    }
+}

processor/src/test/java/org/mapstruct/ap/test/collection/defaultimplementation/Source.java

@@ -0,0 +1,53 @@
+/**
+ *  Copyright 2012-2013 Gunnar Morling (http://www.gunnarmorling.de/)
+ *
+ *  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.collection.defaultimplementation;
+
+import java.util.Collection;
+import java.util.List;
+import java.util.Set;
+
+public class Source {
+
+    private List<SourceFoo> fooList;
+
+    private Set<SourceFoo> fooSet;
+
+    private Collection<SourceFoo> fooCollection;
+
+    public List<SourceFoo> getFooList() {
+        return fooList;
+    }
+
+    public void setFooList(List<SourceFoo> fooList) {
+        this.fooList = fooList;
+    }
+
+    public Set<SourceFoo> getFooSet() {
+        return fooSet;
+    }
+
+    public void setFooSet(Set<SourceFoo> fooSet) {
+        this.fooSet = fooSet;
+    }
+
+    public Collection<SourceFoo> getFooCollection() {
+        return fooCollection;
+    }
+
+    public void setFooCollection(Collection<SourceFoo> fooCollection) {
+        this.fooCollection = fooCollection;
+    }
+}

processor/src/test/java/org/mapstruct/ap/test/collection/defaultimplementation/SourceFoo.java

@@ -0,0 +1,36 @@
+/**
+ *  Copyright 2012-2013 Gunnar Morling (http://www.gunnarmorling.de/)
+ *
+ *  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.collection.defaultimplementation;
+
+public class SourceFoo {
+
+    private String name;
+
+    public SourceFoo() {
+    }
+
+    public SourceFoo(String name) {
+        this.name = name;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+}

processor/src/test/java/org/mapstruct/ap/test/collection/defaultimplementation/SourceTargetMapper.java

@@ -0,0 +1,40 @@
+/**
+ *  Copyright 2012-2013 Gunnar Morling (http://www.gunnarmorling.de/)
+ *
+ *  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.collection.defaultimplementation;
+
+
+import java.util.Collection;
+import java.util.List;
+import java.util.Set;
+
+import org.mapstruct.Mapper;
+import org.mapstruct.Mappers;
+
+@Mapper
+public interface SourceTargetMapper {
+
+    public static SourceTargetMapper INSTANCE = Mappers.getMapper( SourceTargetMapper.class );
+
+    Target sourceToTarget(Source source);
+
+    TargetFoo sourceFooToTargetFoo(SourceFoo sourceFoo);
+
+    List<TargetFoo> sourceFoosToTargetFoos(List<SourceFoo> foos);
+
+    Set<TargetFoo> sourceFoosToTargetFoos(Set<SourceFoo> foos);
+
+    Collection<TargetFoo> sourceFoosToTargetFoos(Collection<SourceFoo> foos);
+}

processor/src/test/java/org/mapstruct/ap/test/collection/defaultimplementation/Target.java

@@ -0,0 +1,53 @@
+/**
+ *  Copyright 2012-2013 Gunnar Morling (http://www.gunnarmorling.de/)
+ *
+ *  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.collection.defaultimplementation;
+
+import java.util.Collection;
+import java.util.List;
+import java.util.Set;
+
+public class Target {
+
+    private List<TargetFoo> fooList;
+
+    private Set<TargetFoo> fooSet;
+
+    private Collection<TargetFoo> fooCollection;
+
+    public List<TargetFoo> getFooList() {
+        return fooList;
+    }
+
+    public void setFooList(List<TargetFoo> fooList) {
+        this.fooList = fooList;
+    }
+
+    public Set<TargetFoo> getFooSet() {
+        return fooSet;
+    }
+
+    public void setFooSet(Set<TargetFoo> fooSet) {
+        this.fooSet = fooSet;
+    }
+
+    public Collection<TargetFoo> getFooCollection() {
+        return fooCollection;
+    }
+
+    public void setFooCollection(Collection<TargetFoo> fooCollection) {
+        this.fooCollection = fooCollection;
+    }
+}

processor/src/test/java/org/mapstruct/ap/test/collection/defaultimplementation/TargetFoo.java

@@ -0,0 +1,67 @@
+/**
+ *  Copyright 2012-2013 Gunnar Morling (http://www.gunnarmorling.de/)
+ *
+ *  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.collection.defaultimplementation;
+
+public class TargetFoo {
+
+    private String name;
+
+    public TargetFoo() {
+    }
+
+    public TargetFoo(String name) {
+        this.name = name;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    @Override
+    public int hashCode() {
+        final int prime = 31;
+        int result = 1;
+        result = prime * result + ( ( name == null ) ? 0 : name.hashCode() );
+        return result;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if ( this == obj ) {
+            return true;
+        }
+        if ( obj == null ) {
+            return false;
+        }
+        if ( getClass() != obj.getClass() ) {
+            return false;
+        }
+        TargetFoo other = (TargetFoo) obj;
+        if ( name == null ) {
+            if ( other.name != null ) {
+                return false;
+            }
+        }
+        else if ( !name.equals( other.name ) ) {
+            return false;
+        }
+        return true;
+    }
+}

processor/src/test/java/org/mapstruct/ap/test/model/Car.java

@@ -15,8 +15,8 @@
  */
 package org.mapstruct.ap.test.model;
 
-import java.util.ArrayList;
 import java.util.Date;
+import java.util.List;
 
 public class Car {
 
@@ -24,14 +24,14 @@ public class Car {
     private int numberOfSeats;
     private Date manufacturingDate;
     private Person driver;
-    private ArrayList<Person> passengers;
+    private List<Person> passengers;
     private int price;
     private Category category;
 
     public Car() {
     }
 
-    public Car(String make, int numberOfSeats, Date manufacturingDate, Person driver, ArrayList<Person> passengers) {
+    public Car(String make, int numberOfSeats, Date manufacturingDate, Person driver, List<Person> passengers) {
         this.make = make;
         this.numberOfSeats = numberOfSeats;
         this.manufacturingDate = manufacturingDate;
@@ -71,11 +71,11 @@ public class Car {
         this.driver = driver;
     }
 
-    public ArrayList<Person> getPassengers() {
+    public List<Person> getPassengers() {
         return passengers;
     }
 
-    public void setPassengers(ArrayList<Person> passengers) {
+    public void setPassengers(List<Person> passengers) {
         this.passengers = passengers;
     }
 

processor/src/test/java/org/mapstruct/ap/test/model/CarDto.java

@@ -15,7 +15,7 @@
  */
 package org.mapstruct.ap.test.model;
 
-import java.util.ArrayList;
+import java.util.List;
 
 public class CarDto {
 
@@ -23,14 +23,14 @@ public class CarDto {
     private int seatCount;
     private String manufacturingYear;
     private PersonDto driver;
-    private ArrayList<PersonDto> passengers;
+    private List<PersonDto> passengers;
     private Long price;
     private String category;
 
     public CarDto() {
     }
 
-    public CarDto(String make, int seatCount, String manufacturingYear, PersonDto driver, ArrayList<PersonDto> passengers) {
+    public CarDto(String make, int seatCount, String manufacturingYear, PersonDto driver, List<PersonDto> passengers) {
         this.make = make;
         this.seatCount = seatCount;
         this.manufacturingYear = manufacturingYear;
@@ -70,11 +70,11 @@ public class CarDto {
         this.driver = driver;
     }
 
-    public ArrayList<PersonDto> getPassengers() {
+    public List<PersonDto> getPassengers() {
         return passengers;
     }
 
-    public void setPassengers(ArrayList<PersonDto> passengers) {
+    public void setPassengers(List<PersonDto> passengers) {
         this.passengers = passengers;
     }
 

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

@@ -15,7 +15,7 @@
  */
 package org.mapstruct.ap.test.model;
 
-import java.util.ArrayList;
+import java.util.List;
 
 import org.mapstruct.Mapper;
 import org.mapstruct.Mappers;
@@ -35,15 +35,15 @@ public interface CarMapper {
 
     Car carDtoToCar(CarDto carDto);
 
-    ArrayList<CarDto> carsToCarDtos(ArrayList<Car> cars);
+    List<CarDto> carsToCarDtos(List<Car> cars);
 
-    ArrayList<Car> carDtosToCars(ArrayList<CarDto> carDtos);
+    List<Car> carDtosToCars(List<CarDto> carDtos);
 
     PersonDto personToPersonDto(Person person);
 
     Person personDtoToPerson(PersonDto personDto);
 
-    ArrayList<PersonDto> personsToPersonDtos(ArrayList<Person> persons);
+    List<PersonDto> personsToPersonDtos(List<Person> persons);
 
-    ArrayList<Person> personDtosToPersons(ArrayList<PersonDto> personDtos);
+    List<Person> personDtosToPersons(List<PersonDto> personDtos);
 }