/**
* 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.source.selector;
import java.util.ArrayList;
import java.util.List;
import javax.lang.model.element.Element;
import javax.lang.model.element.ElementKind;
import javax.lang.model.element.TypeElement;
import javax.lang.model.type.TypeMirror;
import javax.lang.model.util.Elements;
import javax.lang.model.util.Types;
import javax.xml.bind.annotation.XmlElementDecl;
import javax.xml.bind.annotation.XmlElementRef;
import org.mapstruct.ap.internal.model.common.Type;
import org.mapstruct.ap.internal.model.source.Method;
import org.mapstruct.ap.internal.model.source.SourceMethod;
import org.mapstruct.ap.internal.prism.XmlElementDeclPrism;
import org.mapstruct.ap.internal.prism.XmlElementRefPrism;
/**
* Finds the {@link XmlElementRef} annotation on a field (of the mapping result type or its super types) matching the
* target property name. Then selects those methods with matching {@code name} and {@code scope} attributes of the
* {@link XmlElementDecl} annotation, if that is present. Matching happens in the following order:
* <ol>
* <li>Name and Scope matches</li>
* <li>Scope matches</li>
* <li>Name matches</li>
* </ol>
* If there are name and scope matches, only those will be returned, otherwise the next in line (scope matches), etc. If
* the given method is not annotated with {@code XmlElementDecl} it will be considered as matching.
*
* @author Sjaak Derksen
*/
public class XmlElementDeclSelector implements MethodSelector {
private final Types typeUtils;
private final Elements elementUtils;
public XmlElementDeclSelector( Types typeUtils, Elements elementUtils) {
this.typeUtils = typeUtils;
this.elementUtils = elementUtils;
}
@Override
public <T extends Method> List<SelectedMethod<T>> getMatchingMethods(Method mappingMethod,
List<SelectedMethod<T>> methods,
List<Type> sourceTypes, Type targetType,
SelectionCriteria criteria) {
List<SelectedMethod<T>> nameMatches = new ArrayList<SelectedMethod<T>>();
List<SelectedMethod<T>> scopeMatches = new ArrayList<SelectedMethod<T>>();
List<SelectedMethod<T>> nameAndScopeMatches = new ArrayList<SelectedMethod<T>>();
XmlElementRefInfo xmlElementRefInfo =
findXmlElementRef( mappingMethod.getResultType(), criteria.getTargetPropertyName() );
for ( SelectedMethod<T> candidate : methods ) {
if ( !( candidate.getMethod() instanceof SourceMethod ) ) {
continue;
}
SourceMethod candidateMethod = (SourceMethod) candidate.getMethod();
XmlElementDeclPrism xmlElememtDecl = XmlElementDeclPrism.getInstanceOn( candidateMethod.getExecutable() );
if ( xmlElememtDecl == null ) {
continue;
}
String name = xmlElememtDecl.name();
TypeMirror scope = xmlElememtDecl.scope();
boolean nameIsSetAndMatches = name != null && name.equals( xmlElementRefInfo.nameValue() );
boolean scopeIsSetAndMatches =
scope != null && typeUtils.isSameType( scope, xmlElementRefInfo.sourceType() );
if ( nameIsSetAndMatches ) {
if ( scopeIsSetAndMatches ) {
nameAndScopeMatches.add( candidate );
}
else {
nameMatches.add( candidate );
}
}
else if ( scopeIsSetAndMatches ) {
scopeMatches.add( candidate );
}
}
if ( nameAndScopeMatches.size() > 0 ) {
return nameAndScopeMatches;
}
else if ( scopeMatches.size() > 0 ) {
return scopeMatches;
}
else if ( nameMatches.size() > 0 ) {
return nameMatches;
}
else {
return methods;
}
}
/**
* Iterate through resultType and its super types to find a field named targetPropertyName and return information
* about:
* <ul>
* <li>what the value of the name property of the XmlElementRef annotation on that field was</li>
* <li>on which type the field was found</li>
* </ul>
*
* @param resultType starting point of the iteration
* @param targetPropertyName name of the field we are looking for
* @return an XmlElementRefInfo containing the information
*/
private XmlElementRefInfo findXmlElementRef(Type resultType, String targetPropertyName) {
TypeMirror startingMirror = resultType.getTypeMirror();
XmlElementRefInfo defaultInfo = new XmlElementRefInfo( targetPropertyName, startingMirror );
if ( targetPropertyName == null ) {
/*
* sometimes MethodSelectors seem to be called with criteria.getTargetPropertyName() == null so we need to
* avoid NPEs for that case.
*/
return defaultInfo;
}
TypeMirror currentMirror = startingMirror;
TypeElement currentElement = resultType.getTypeElement();
/*
* Outer loop for resultType and its super types. "currentElement" will be null once we reach Object and try to
* get a TypeElement for its super type.
*/
while ( currentElement != null ) {
/*
* Inner loop tries to find a field with the targetPropertyName and assumes that where the XmlElementRef is
* set
*/
for ( Element enclosed : currentElement.getEnclosedElements() ) {
if ( enclosed.getKind().equals( ElementKind.FIELD )
&& enclosed.getSimpleName().contentEquals( targetPropertyName ) ) {
XmlElementRefPrism xmlElementRef = XmlElementRefPrism.getInstanceOn( enclosed );
if ( xmlElementRef != null ) {
return new XmlElementRefInfo( xmlElementRef.name(), currentMirror );
}
}
}
currentMirror = currentElement.getSuperclass();
currentElement = elementUtils.getTypeElement( currentMirror.toString() );
}
return defaultInfo;
}
private static class XmlElementRefInfo {
private final String nameValue;
private final TypeMirror sourceType;
XmlElementRefInfo(String nameValue, TypeMirror sourceType) {
this.nameValue = nameValue;
this.sourceType = sourceType;
}
public String nameValue() {
return nameValue;
}
public TypeMirror sourceType() {
return sourceType;
}
}
}