#782 Add BuilderInfo to SPI

The implementors of the SPI should return all the required information

processor/src/main/java/org/mapstruct/ap/MappingProcessor.java

@@ -52,7 +52,7 @@ import org.mapstruct.ap.internal.processor.ModelElementProcessor.ProcessorContex
 import org.mapstruct.ap.internal.util.AnnotationProcessingException;
 import org.mapstruct.ap.internal.util.AnnotationProcessorContext;
 import org.mapstruct.ap.internal.util.RoundContext;
-import org.mapstruct.ap.internal.util.TypeHierarchyErroneousException;
+import org.mapstruct.ap.spi.TypeHierarchyErroneousException;
 
 /**
  * A JSR 269 annotation {@link Processor} which generates the implementations for mapper interfaces (interfaces

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

@@ -40,8 +40,8 @@ import javax.tools.Diagnostic;
 import org.mapstruct.ap.internal.model.PropertyMapping.ConstantMappingBuilder;
 import org.mapstruct.ap.internal.model.PropertyMapping.JavaExpressionMappingBuilder;
 import org.mapstruct.ap.internal.model.PropertyMapping.PropertyMappingBuilder;
+import org.mapstruct.ap.internal.model.common.BuilderType;
 import org.mapstruct.ap.internal.model.common.Parameter;
-import org.mapstruct.ap.internal.model.common.ParameterBinding;
 import org.mapstruct.ap.internal.model.common.Type;
 import org.mapstruct.ap.internal.model.dependency.GraphAnalyzer;
 import org.mapstruct.ap.internal.model.dependency.GraphAnalyzer.GraphAnalyzerBuilder;
@@ -244,33 +244,8 @@ public class BeanMappingMethod extends NormalTypeMappingMethod {
                 ( (ForgedMethod) method ).addThrownTypes( factoryMethod.getThrownTypes() );
             }
 
-            MethodReference finalizeMethod = null;
+            MethodReference finalizeMethod = getFinalizeMethod(
-            if (
+                resultType == null ? method.getReturnType() : resultType );
-                !method.getReturnType().isVoid() &&
-                    ( resultType != null
-                        && !ctx.getTypeUtils().isAssignable(
-                        resultType.getMappingType().getTypeMirror(),
-                        resultType.getTypeMirror()
-                    ) ||
-                        !ctx.getTypeUtils().isSameType(
-                            method.getReturnType().getMappingType().getTypeMirror(),
-                            method.getReturnType().getTypeMirror()
-                        )
-                    )
-                ) {
-                finalizeMethod = MethodReference.forForgedMethod(
-                    new ForgedMethod(
-                        "build",
-                        method.getReturnType(),
-                        method.getReturnType(),
-                        null,
-                        null,
-                        Collections.<Parameter>emptyList(),
-                        null
-                    ),
-                    Collections.<ParameterBinding>emptyList()
-                );
-            }
 
             return new BeanMappingMethod(
                 method,
@@ -285,6 +260,20 @@ public class BeanMappingMethod extends NormalTypeMappingMethod {
             );
         }
 
+        private MethodReference getFinalizeMethod(Type resultType) {
+            if ( method.getReturnType().isVoid() ||
+                resultType.getMappingType().isAssignableTo( resultType ) ) {
+                return null;
+            }
+            BuilderType builderType = resultType.getBuilderType();
+            if ( builderType == null ) {
+                // If the mapping type is assignable to the result type this should never happen
+                return null;
+            }
+
+            return MethodReference.forMethodCall( builderType.getBuildMethod() );
+        }
+
         /**
          * If there were nested defined targets that have not been handled. Then we need to process them at the end.
          */

processor/src/main/java/org/mapstruct/ap/internal/model/MethodReference.java

@@ -118,7 +118,7 @@ public class MethodReference extends ModelElement implements Assignment {
         this.name = method.getName();
     }
 
-    private MethodReference(String name, Type definingType) {
+    private MethodReference(String name, Type definingType, boolean isStatic) {
         this.name = name;
         this.definingType = definingType;
         this.sourceParameters = Collections.emptyList();
@@ -130,7 +130,7 @@ public class MethodReference extends ModelElement implements Assignment {
         this.contextParam = null;
         this.parameterBindings = Collections.emptyList();
         this.providingParameter = null;
-        this.isStatic = true;
+        this.isStatic = isStatic;
     }
 
     public MapperReference getDeclaringMapper() {
@@ -335,6 +335,10 @@ public class MethodReference extends ModelElement implements Assignment {
     }
 
     public static MethodReference forStaticBuilder(String builderCreationMethod, Type definingType) {
-        return new MethodReference( builderCreationMethod, definingType );
+        return new MethodReference( builderCreationMethod, definingType, true );
+    }
+
+    public static MethodReference forMethodCall(String methodName) {
+        return new MethodReference( methodName, null, false );
     }
 }

processor/src/main/java/org/mapstruct/ap/internal/model/common/BuilderType.java

@@ -0,0 +1,113 @@
+/**
+ *  Copyright 2012-2017 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.internal.model.common;
+
+import javax.lang.model.element.ExecutableElement;
+import javax.lang.model.type.TypeMirror;
+import javax.lang.model.util.Types;
+
+import org.mapstruct.ap.spi.BuilderInfo;
+
+/**
+ * @author Filip Hrisafov
+ */
+public class BuilderType {
+
+    private final Type builder;
+    private final Type owner;
+    private final Type buildingType;
+    private final ExecutableElement builderCreationMethod;
+    private final ExecutableElement buildMethod;
+
+    private BuilderType(
+        Type builder,
+        Type owner,
+        Type buildingType,
+        ExecutableElement builderCreationMethod,
+        ExecutableElement buildMethod
+    ) {
+        this.builder = builder;
+        this.owner = owner;
+        this.buildingType = buildingType;
+        this.builderCreationMethod = builderCreationMethod;
+        this.buildMethod = buildMethod;
+    }
+
+    public Type getBuilder() {
+        return builder;
+    }
+
+    public Type getOwner() {
+        return owner;
+    }
+
+    public Type getBuildingType() {
+        return buildingType;
+    }
+
+    public ExecutableElement getBuilderCreationMethod() {
+        return builderCreationMethod;
+    }
+
+    public String getBuildMethod() {
+        return buildMethod.getSimpleName().toString();
+    }
+
+    public BuilderInfo asBuilderInfo() {
+        return new BuilderInfo.Builder()
+            .builderCreationMethod( this.builderCreationMethod )
+            .buildMethod( this.buildMethod )
+            .build();
+    }
+
+    public static BuilderType create(BuilderInfo builderInfo, Type typeToBuild, TypeFactory typeFactory,
+        Types typeUtils) {
+        if ( builderInfo == null ) {
+            return null;
+        }
+        ExecutableElement buildMethod = builderInfo.getBuildMethod();
+        if ( !typeUtils.isAssignable( buildMethod.getReturnType(), typeToBuild.getTypeMirror() ) ) {
+            //TODO throw error
+            throw new IllegalArgumentException( "Build return type is not assignable" );
+        }
+
+        Type builder = typeFactory.getType( builderInfo.getBuilderCreationMethod().getReturnType() );
+        ExecutableElement builderCreationMethod = builderInfo.getBuilderCreationMethod();
+        Type owner;
+        TypeMirror builderCreationOwner = builderCreationMethod.getEnclosingElement().asType();
+        if ( typeUtils.isSameType( builderCreationOwner, typeToBuild.getTypeMirror() ) ) {
+            owner = typeToBuild;
+        }
+        else if ( typeUtils.isSameType( builder.getTypeMirror(), builderCreationOwner ) ) {
+            owner = builder;
+        }
+        else {
+            owner = typeFactory.getType( builderCreationOwner );
+        }
+
+
+        return new BuilderType(
+            builder,
+            owner,
+            typeToBuild,
+            builderCreationMethod,
+            buildMethod
+        );
+    }
+}

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

@@ -49,6 +49,7 @@ import org.mapstruct.ap.internal.util.Filters;
 import org.mapstruct.ap.internal.util.Nouns;
 import org.mapstruct.ap.internal.util.accessor.Accessor;
 import org.mapstruct.ap.internal.util.accessor.ExecutableElementAccessor;
+import org.mapstruct.ap.spi.BuilderInfo;
 
 /**
  * Represents (a reference to) the type of a bean property, parameter etc. Types are managed per generated source file.
@@ -72,7 +73,7 @@ public class Type extends ModelElement implements Comparable<Type> {
 
     private final ImplementationType implementationType;
     private final Type componentType;
-    private final Type builderType;
+    private final BuilderType builderType;
 
     private final String packageName;
     private final String name;
@@ -105,7 +106,7 @@ public class Type extends ModelElement implements Comparable<Type> {
     public Type(Types typeUtils, Elements elementUtils, TypeFactory typeFactory,
                 TypeMirror typeMirror, TypeElement typeElement,
                 List<Type> typeParameters, ImplementationType implementationType, Type componentType,
-                Type builderType,
+                BuilderInfo builderInfo,
                 String packageName, String name, String qualifiedName,
                 boolean isInterface, boolean isEnumType, boolean isIterableType,
                 boolean isCollectionType, boolean isMapType, boolean isStreamType, boolean isImported) {
@@ -119,7 +120,6 @@ public class Type extends ModelElement implements Comparable<Type> {
         this.typeParameters = typeParameters;
         this.componentType = componentType;
         this.implementationType = implementationType;
-        this.builderType = builderType;
 
         this.packageName = packageName;
         this.name = name;
@@ -149,6 +149,8 @@ public class Type extends ModelElement implements Comparable<Type> {
         else {
             enumConstants = Collections.emptyList();
         }
+
+        this.builderType = BuilderType.create( builderInfo, this, this.typeFactory, this.typeUtils );
     }
     //CHECKSTYLE:ON
 
@@ -176,12 +178,12 @@ public class Type extends ModelElement implements Comparable<Type> {
         return componentType;
     }
 
-    public Type getBuilderType() {
+    public BuilderType getBuilderType() {
         return builderType;
     }
 
     public Type getMappingType() {
-        return builderType != null ? builderType : this;
+        return builderType != null ? builderType.getBuilder() : this;
     }
 
     public boolean isPrimitive() {
@@ -366,7 +368,7 @@ public class Type extends ModelElement implements Comparable<Type> {
             typeParameters,
             implementationType,
             componentType,
-            builderType,
+            builderType == null ? null : builderType.asBuilderInfo(),
             packageName,
             name,
             qualifiedName,

processor/src/main/java/org/mapstruct/ap/internal/model/common/TypeFactory.java

@@ -58,11 +58,12 @@ import org.mapstruct.ap.internal.util.Collections;
 import org.mapstruct.ap.internal.util.JavaStreamConstants;
 import org.mapstruct.ap.internal.util.RoundContext;
 import org.mapstruct.ap.internal.util.Services;
-import org.mapstruct.ap.internal.util.TypeHierarchyErroneousException;
 import org.mapstruct.ap.internal.util.accessor.Accessor;
 import org.mapstruct.ap.spi.AstModifyingAnnotationProcessor;
+import org.mapstruct.ap.spi.BuilderInfo;
 import org.mapstruct.ap.spi.BuilderProvider;
 import org.mapstruct.ap.spi.DefaultBuilderProvider;
+import org.mapstruct.ap.spi.TypeHierarchyErroneousException;
 
 import static org.mapstruct.ap.internal.model.common.ImplementationType.withDefaultConstructor;
 import static org.mapstruct.ap.internal.model.common.ImplementationType.withInitialCapacity;
@@ -170,7 +171,7 @@ public class TypeFactory {
         }
 
         ImplementationType implementationType = getImplementationType( mirror );
-        Type builderType = findBuilder( mirror );
+        BuilderInfo builderInfo = findBuilder( mirror );
 
         boolean isIterableType = typeUtils.isSubtype( mirror, iterableType );
         boolean isCollectionType = typeUtils.isSubtype( mirror, collectionType );
@@ -256,7 +257,7 @@ public class TypeFactory {
             getTypeParameters( mirror, false ),
             implementationType,
             componentType,
-            builderType,
+            builderInfo,
             packageName,
             name,
             qualifiedName,
@@ -486,9 +487,8 @@ public class TypeFactory {
         return null;
     }
 
-    private Type findBuilder(TypeMirror type) {
+    private BuilderInfo findBuilder(TypeMirror type) {
-        TypeMirror builder = BUILDER_PROVIDER.findBuilder( type, elementUtils, typeUtils );
+        return BUILDER_PROVIDER.findBuilderInfo( type, elementUtils, typeUtils );
-        return builder == null ? null : getType( builder );
     }
 
     private TypeMirror getComponentType(TypeMirror mirror) {

processor/src/main/java/org/mapstruct/ap/internal/processor/creation/MappingResolverImpl.java

@@ -22,13 +22,12 @@ import static java.util.Collections.singletonList;
 import static org.mapstruct.ap.internal.util.Collections.first;
 
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
 
+import javax.lang.model.element.ElementKind;
 import javax.lang.model.element.ExecutableElement;
-import javax.lang.model.element.Modifier;
 import javax.lang.model.element.TypeElement;
 import javax.lang.model.type.DeclaredType;
 import javax.lang.model.type.ExecutableType;
@@ -46,6 +45,7 @@ import org.mapstruct.ap.internal.model.MappingBuilderContext.MappingResolver;
 import org.mapstruct.ap.internal.model.MethodReference;
 import org.mapstruct.ap.internal.model.VirtualMappingMethod;
 import org.mapstruct.ap.internal.model.common.Assignment;
+import org.mapstruct.ap.internal.model.common.BuilderType;
 import org.mapstruct.ap.internal.model.common.ConversionContext;
 import org.mapstruct.ap.internal.model.common.DefaultConversionContext;
 import org.mapstruct.ap.internal.model.common.FormattingParameters;
@@ -60,7 +60,6 @@ import org.mapstruct.ap.internal.model.source.selector.MethodSelectors;
 import org.mapstruct.ap.internal.model.source.selector.SelectedMethod;
 import org.mapstruct.ap.internal.model.source.selector.SelectionCriteria;
 import org.mapstruct.ap.internal.util.Collections;
-import org.mapstruct.ap.internal.util.Executables;
 import org.mapstruct.ap.internal.util.FormattingMessager;
 import org.mapstruct.ap.internal.util.Message;
 import org.mapstruct.ap.internal.util.Strings;
@@ -143,7 +142,7 @@ public class MappingResolverImpl implements MappingResolver {
                 SelectionCriteria.forFactoryMethods( selectionParameters ) );
 
         if (matchingFactoryMethods.isEmpty()) {
-            return findBuilderFactoryMethod( mappingMethod, targetType );
+            return findBuilderFactoryMethod( targetType );
         }
 
         if ( matchingFactoryMethods.size() > 1 ) {
@@ -166,37 +165,24 @@ public class MappingResolverImpl implements MappingResolver {
             matchingFactoryMethod.getParameterBindings() );
     }
 
-    private MethodReference findBuilderFactoryMethod(Method mappingMethod, Type targetType) {
+    private MethodReference findBuilderFactoryMethod(Type targetType) {
-        if ( targetType.getBuilderType() == null ) {
+        BuilderType builder = targetType.getBuilderType();
-            return null;
+        if ( builder == null ) {
-        }
-        Type builderType = targetType.getBuilderType();
-
-        Type returnType = mappingMethod.getReturnType();
-        List<ExecutableElement> builderCreators = new ArrayList<ExecutableElement>();
-        for ( ExecutableElement executableElement : Executables.getAllEnclosedExecutableElements(
-            elementsUtils,
-            returnType.getTypeElement()
-        ) ) {
-            if ( !executableElement.getModifiers().containsAll( Arrays.asList( Modifier.PUBLIC, Modifier.STATIC ) )
-                || !executableElement.getParameters().isEmpty()
-                || !typeUtils.isSameType( executableElement.getReturnType(), builderType.getTypeMirror() )) {
-                continue;
-            }
-            builderCreators.add( executableElement );
-        }
-
-        if ( builderCreators.size() == 1 ) {
-            return MethodReference.forStaticBuilder( first( builderCreators ).getSimpleName().toString(), targetType );
-        }
-        else if ( builderCreators.size() > 1 ) {
-            //error
             return null;
         }
 
-        // Find the default constructor, if it exists, and construct the FactoryMethod
+        ExecutableElement builderCreationMethod = builder.getBuilderCreationMethod();
-        // We could also live with assuming it exists
+        if ( builderCreationMethod.getKind() == ElementKind.CONSTRUCTOR ) {
-        return null;
+            // If the builder creation method is a constructor it would be handled properly down the line
+            return null;
+        }
+
+        if ( !builder.getBuildingType().isAssignableTo( targetType ) ) {
+            //TODO print error message
+            return null;
+        }
+
+        return MethodReference.forStaticBuilder( builderCreationMethod.getSimpleName().toString(), builder.getOwner() );
     }
 
     private MapperReference findMapperReference(Method method) {

processor/src/main/java/org/mapstruct/ap/internal/util/Executables.java

@@ -47,6 +47,7 @@ import org.mapstruct.ap.internal.util.accessor.VariableElementAccessor;
 import org.mapstruct.ap.spi.AccessorNamingStrategy;
 import org.mapstruct.ap.spi.DefaultAccessorNamingStrategy;
 import org.mapstruct.ap.spi.MethodType;
+import org.mapstruct.ap.spi.TypeHierarchyErroneousException;
 
 /**
  * Provides functionality around {@link ExecutableElement}s.

processor/src/main/java/org/mapstruct/ap/spi/BuilderInfo.java

@@ -0,0 +1,68 @@
+/**
+ *  Copyright 2012-2017 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.spi;
+
+import javax.lang.model.element.ExecutableElement;
+
+/**
+ * @author Filip Hrisafov
+ */
+public class BuilderInfo {
+
+    private final ExecutableElement builderCreationMethod;
+    private final ExecutableElement buildMethod;
+
+    private BuilderInfo(ExecutableElement builderCreationMethod, ExecutableElement buildMethod) {
+        this.builderCreationMethod = builderCreationMethod;
+        this.buildMethod = buildMethod;
+    }
+
+    public ExecutableElement getBuilderCreationMethod() {
+        return builderCreationMethod;
+    }
+
+    public ExecutableElement getBuildMethod() {
+        return buildMethod;
+    }
+
+    public static class Builder {
+        private ExecutableElement builderCreationMethod;
+        private ExecutableElement buildMethod;
+
+        public Builder builderCreationMethod(ExecutableElement method) {
+            this.builderCreationMethod = method;
+            return this;
+        }
+
+        public Builder buildMethod(ExecutableElement method) {
+            this.buildMethod = method;
+            return this;
+        }
+
+        public BuilderInfo build() {
+            if ( builderCreationMethod == null ) {
+                throw new IllegalArgumentException( "Builder creation method is mandatory" );
+            }
+            else if ( buildMethod == null ) {
+                throw new IllegalArgumentException( "Build method is mandatory" );
+            }
+            return new BuilderInfo( builderCreationMethod, buildMethod );
+        }
+    }
+}

processor/src/main/java/org/mapstruct/ap/spi/BuilderProvider.java

@@ -29,5 +29,5 @@ import javax.lang.model.util.Types;
  */
 public interface BuilderProvider {
 
-    TypeMirror findBuilder(TypeMirror type, Elements elements, Types types);
+    BuilderInfo findBuilderInfo(TypeMirror type, Elements elements, Types types);
 }

processor/src/main/java/org/mapstruct/ap/spi/DefaultBuilderProvider.java

@@ -22,9 +22,9 @@ import java.util.List;
 import java.util.regex.Pattern;
 import javax.lang.model.element.ExecutableElement;
 import javax.lang.model.element.Modifier;
-import javax.lang.model.element.Name;
 import javax.lang.model.element.TypeElement;
 import javax.lang.model.type.DeclaredType;
+import javax.lang.model.type.TypeKind;
 import javax.lang.model.type.TypeMirror;
 import javax.lang.model.util.ElementFilter;
 import javax.lang.model.util.Elements;
@@ -42,7 +42,19 @@ public class DefaultBuilderProvider implements BuilderProvider {
     private static final Pattern JAVA_JAVAX_PACKAGE = Pattern.compile( "^javax?\\..*" );
 
     @Override
-    public TypeMirror findBuilder(TypeMirror type, Elements elements, Types types) {
+    public BuilderInfo findBuilderInfo(TypeMirror type, Elements elements, Types types) {
+        TypeElement typeElement = getTypeElement( type );
+        if ( typeElement == null ) {
+            return null;
+        }
+
+        return findBuilderInfo( typeElement, elements, types );
+    }
+
+    protected TypeElement getTypeElement(TypeMirror type) {
+        if ( type.getKind() == TypeKind.ERROR ) {
+            throw new TypeHierarchyErroneousException( type );
+        }
         DeclaredType declaredType = type.accept(
             new SimpleTypeVisitor6<DeclaredType, Void>() {
                 @Override
@@ -57,7 +69,7 @@ public class DefaultBuilderProvider implements BuilderProvider {
             return null;
         }
 
-        TypeElement typeElement = declaredType.asElement().accept(
+        return declaredType.asElement().accept(
             new SimpleElementVisitor6<TypeElement, Void>() {
                 @Override
                 public TypeElement visitType(TypeElement e, Void p) {
@@ -66,30 +78,63 @@ public class DefaultBuilderProvider implements BuilderProvider {
             },
             null
         );
-
-        return findBuilder( typeElement, elements, types );
     }
 
-    protected TypeMirror findBuilder(TypeElement typeElement, Elements elements, Types types) {
+    protected BuilderInfo findBuilderInfo(TypeElement typeElement, Elements elements, Types types) {
-        Name name = typeElement.getQualifiedName();
+        if ( shouldIgnore( typeElement ) ) {
-        if ( name.length() == 0 || JAVA_JAVAX_PACKAGE.matcher( name ).matches() ) {
             return null;
         }
-        List<ExecutableElement> methods = ElementFilter.methodsIn( typeElement.getEnclosedElements() );
 
+        List<ExecutableElement> methods = ElementFilter.methodsIn( typeElement.getEnclosedElements() );
         for ( ExecutableElement method : methods ) {
-            if ( isBuilderMethod( method ) ) {
+            if ( isPossibleBuilderCreationMethod( method, typeElement, types ) ) {
-                return method.getReturnType();
+                TypeElement builderElement = getTypeElement( method.getReturnType() );
+                ExecutableElement buildMethod = findBuildMethod( builderElement, typeElement, types );
+                if ( buildMethod != null ) {
+                    return new BuilderInfo.Builder()
+                        .builderCreationMethod( method )
+                        .buildMethod( buildMethod )
+                        .build();
+                }
+            }
+        }
+        return findBuilderInfo( typeElement.getSuperclass(), elements, types );
+    }
+
+    protected boolean isPossibleBuilderCreationMethod(ExecutableElement method, TypeElement typeElement, Types types) {
+        return method.getParameters().isEmpty()
+            && method.getModifiers().contains( Modifier.PUBLIC )
+            && method.getModifiers().contains( Modifier.STATIC )
+            && !types.isSameType( method.getReturnType(), typeElement.asType() );
+    }
+
+    protected ExecutableElement findBuildMethod(TypeElement builderElement, TypeElement typeElement, Types types) {
+        if ( shouldIgnore( builderElement ) ) {
+            return null;
+        }
+
+        List<ExecutableElement> builderMethods = ElementFilter.methodsIn( builderElement.getEnclosedElements() );
+        for ( ExecutableElement buildMethod : builderMethods ) {
+            if ( isBuildMethod( buildMethod, typeElement, types ) ) {
+                return buildMethod;
             }
         }
 
-        return findBuilder( typeElement.getSuperclass(), elements, types );
+        return findBuildMethod(
+            getTypeElement( builderElement.getSuperclass() ),
+            typeElement,
+            types
+        );
     }
 
-    protected boolean isBuilderMethod(ExecutableElement method) {
+    protected boolean isBuildMethod(ExecutableElement buildMethod, TypeElement typeElement,
-        return method.getParameters().isEmpty()
+        Types types) {
-            && method.getSimpleName().toString().equals( "builder" )
+        return buildMethod.getParameters().isEmpty() &&
-            && method.getModifiers().contains( Modifier.PUBLIC )
+            buildMethod.getModifiers().contains( Modifier.PUBLIC )
-            && method.getModifiers().contains( Modifier.STATIC );
+            && types.isAssignable( buildMethod.getReturnType(), typeElement.asType() );
+    }
+
+    protected boolean shouldIgnore(TypeElement typeElement) {
+        return typeElement == null || JAVA_JAVAX_PACKAGE.matcher( typeElement.getQualifiedName() ).matches();
     }
 }

processor/src/main/java/org/mapstruct/ap/spi/TypeHierarchyErroneousException.java

@@ -16,7 +16,7 @@
  *  See the License for the specific language governing permissions and
  *  limitations under the License.
  */
-package org.mapstruct.ap.internal.util;
+package org.mapstruct.ap.spi;
 
 import javax.lang.model.element.TypeElement;
 import javax.lang.model.type.TypeMirror;

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

@@ -78,9 +78,7 @@
     </#list>
     <#if returnType.name != "void">
 
-    <#if resultType.builderType??>
+    <#if finalizeMethod??>
-        return ${resultName}.build();
-    <#elseif finalizeMethod??>
         return ${resultName}.<@includeModel object=finalizeMethod />;
     <#else>
         return ${resultName};