com.thoughtworks.xstream.converters.reflection.AbstractReflectionConverter Maven / Gradle / Ivy
/*
* Copyright (C) 2004, 2005, 2006 Joe Walnes.
* Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016 XStream Committers.
* All rights reserved.
*
* The software in this package is published under the terms of the BSD
* style license a copy of which has been included with this distribution in
* the LICENSE.txt file.
*
* Created on 02. March 2006 by Joerg Schaible
*/
package com.thoughtworks.xstream.converters.reflection;
import com.thoughtworks.xstream.converters.ConversionException;
import com.thoughtworks.xstream.converters.Converter;
import com.thoughtworks.xstream.converters.MarshallingContext;
import com.thoughtworks.xstream.converters.SingleValueConverter;
import com.thoughtworks.xstream.converters.UnmarshallingContext;
import com.thoughtworks.xstream.core.Caching;
import com.thoughtworks.xstream.core.ReferencingMarshallingContext;
import com.thoughtworks.xstream.core.util.ArrayIterator;
import com.thoughtworks.xstream.core.util.FastField;
import com.thoughtworks.xstream.core.util.Fields;
import com.thoughtworks.xstream.core.util.HierarchicalStreams;
import com.thoughtworks.xstream.core.util.Primitives;
import com.thoughtworks.xstream.core.util.SerializationMembers;
import com.thoughtworks.xstream.io.ExtendedHierarchicalStreamWriterHelper;
import com.thoughtworks.xstream.io.HierarchicalStreamReader;
import com.thoughtworks.xstream.io.HierarchicalStreamWriter;
import com.thoughtworks.xstream.mapper.CannotResolveClassException;
import com.thoughtworks.xstream.mapper.Mapper;
import java.lang.reflect.Array;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.util.AbstractList;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
public abstract class AbstractReflectionConverter implements Converter, Caching {
protected final ReflectionProvider reflectionProvider;
protected final Mapper mapper;
/**
* @deprecated As of 1.4.8, use {@link #serializationMembers}.
*/
protected transient SerializationMethodInvoker serializationMethodInvoker;
protected transient SerializationMembers serializationMembers;
private transient ReflectionProvider pureJavaReflectionProvider;
public AbstractReflectionConverter(Mapper mapper, ReflectionProvider reflectionProvider) {
this.mapper = mapper;
this.reflectionProvider = reflectionProvider;
serializationMethodInvoker = new SerializationMethodInvoker();
serializationMembers = serializationMethodInvoker.serializationMembers;
}
protected boolean canAccess(Class type) {
try {
reflectionProvider.getFieldOrNull(type, "%");
return true;
} catch (NoClassDefFoundError e) {
// restricted type in GAE
}
return false;
}
public void marshal(Object original, final HierarchicalStreamWriter writer,
final MarshallingContext context) {
final Object source = serializationMembers.callWriteReplace(original);
if (source != original && context instanceof ReferencingMarshallingContext) {
((ReferencingMarshallingContext)context).replace(original, source);
}
if (source.getClass() != original.getClass()) {
String attributeName = mapper.aliasForSystemAttribute("resolves-to");
if (attributeName != null) {
writer.addAttribute(attributeName, mapper.serializedClass(source.getClass()));
}
context.convertAnother(source);
} else {
doMarshal(source, writer, context);
}
}
protected void doMarshal(final Object source, final HierarchicalStreamWriter writer,
final MarshallingContext context) {
final List fields = new ArrayList();
final Map defaultFieldDefinition = new HashMap();
final Class sourceType = source.getClass();
// Attributes might be preferred to child elements ...
reflectionProvider.visitSerializableFields(source, new ReflectionProvider.Visitor() {
final Set writtenAttributes = new HashSet();
public void visit(String fieldName, Class type, Class definedIn, Object value) {
if (!mapper.shouldSerializeMember(definedIn, fieldName)) {
return;
}
if (!defaultFieldDefinition.containsKey(fieldName)) {
Class lookupType = source.getClass();
// See XSTR-457 and OmitFieldsTest
if (definedIn != sourceType
&& !mapper.shouldSerializeMember(lookupType, fieldName)) {
lookupType = definedIn;
}
defaultFieldDefinition.put(
fieldName, reflectionProvider.getField(lookupType, fieldName));
}
SingleValueConverter converter = mapper.getConverterFromItemType(
fieldName, type, definedIn);
if (converter != null) {
final String attribute = mapper.aliasForAttribute(mapper.serializedMember(
definedIn, fieldName));
if (value != null) {
if (writtenAttributes.contains(fieldName)) {
ConversionException exception =
new ConversionException("Cannot write field as attribute for object, attribute name already in use");
exception.add("field-name", fieldName);
exception.add("object-type", sourceType.getName());
throw exception;
}
final String str = converter.toString(value);
if (str != null) {
writer.addAttribute(attribute, str);
}
}
writtenAttributes.add(fieldName);
} else {
fields.add(new FieldInfo(fieldName, type, definedIn, value));
}
}
});
new Object() {
{
final Map hiddenMappers = new HashMap();
for (Iterator fieldIter = fields.iterator(); fieldIter.hasNext();) {
FieldInfo info = (FieldInfo)fieldIter.next();
if (info.value != null) {
final Field defaultField = (Field)defaultFieldDefinition.get(info.fieldName);
Mapper.ImplicitCollectionMapping mapping = mapper
.getImplicitCollectionDefForFieldName(
defaultField.getDeclaringClass() == info.definedIn ? sourceType : info.definedIn,
info.fieldName);
if (mapping != null) {
Set mappings = (Set)hiddenMappers.get(info.fieldName);
if (mappings == null) {
mappings = new HashSet();
mappings.add(mapping);
hiddenMappers.put(info.fieldName, mappings);
} else {
if (!mappings.add(mapping)) {
mapping = null;
}
}
}
if (mapping != null) {
if (context instanceof ReferencingMarshallingContext) {
if (info.value != Collections.EMPTY_LIST
&& info.value != Collections.EMPTY_SET
&& info.value != Collections.EMPTY_MAP) {
ReferencingMarshallingContext refContext = (ReferencingMarshallingContext)context;
refContext.registerImplicit(info.value);
}
}
final boolean isCollection = info.value instanceof Collection;
final boolean isMap = info.value instanceof Map;
final boolean isEntry = isMap && mapping.getKeyFieldName() == null;
final boolean isArray = info.value.getClass().isArray();
for (Iterator iter = isArray
? new ArrayIterator(info.value)
: isCollection ? ((Collection)info.value).iterator() : isEntry
? ((Map)info.value).entrySet().iterator()
: ((Map)info.value).values().iterator(); iter.hasNext();) {
Object obj = iter.next();
final String itemName;
final Class itemType;
if (obj == null) {
itemType = Object.class;
itemName = mapper.serializedClass(null);
} else if (isEntry) {
final String entryName = mapping.getItemFieldName() != null
? mapping.getItemFieldName()
: mapper.serializedClass(Map.Entry.class);
Map.Entry entry = (Map.Entry)obj;
ExtendedHierarchicalStreamWriterHelper.startNode(
writer, entryName, entry.getClass());
writeItem(entry.getKey(), context, writer);
writeItem(entry.getValue(), context, writer);
writer.endNode();
continue;
} else if (mapping.getItemFieldName() != null) {
itemType = mapping.getItemType();
itemName = mapping.getItemFieldName();
} else {
itemType = obj.getClass();
itemName = mapper.serializedClass(itemType);
}
writeField(
info.fieldName, itemName, itemType, info.definedIn, obj);
}
} else {
writeField(
info.fieldName, null, info.type, info.definedIn, info.value);
}
}
}
}
void writeField(String fieldName, String aliasName, Class fieldType,
Class definedIn, Object newObj) {
Class actualType = newObj != null ? newObj.getClass() : fieldType;
ExtendedHierarchicalStreamWriterHelper.startNode(writer, aliasName != null
? aliasName
: mapper.serializedMember(sourceType, fieldName), actualType);
if (newObj != null) {
Class defaultType = mapper.defaultImplementationOf(fieldType);
if (!actualType.equals(defaultType)) {
String serializedClassName = mapper.serializedClass(actualType);
if (!serializedClassName.equals(mapper.serializedClass(defaultType))) {
String attributeName = mapper.aliasForSystemAttribute("class");
if (attributeName != null) {
writer.addAttribute(attributeName, serializedClassName);
}
}
}
final Field defaultField = (Field)defaultFieldDefinition.get(fieldName);
if (defaultField.getDeclaringClass() != definedIn) {
String attributeName = mapper.aliasForSystemAttribute("defined-in");
if (attributeName != null) {
writer.addAttribute(
attributeName, mapper.serializedClass(definedIn));
}
}
Field field = reflectionProvider.getField(definedIn, fieldName);
marshallField(context, newObj, field);
}
writer.endNode();
}
void writeItem(Object item, MarshallingContext context,
HierarchicalStreamWriter writer) {
if (item == null) {
String name = mapper.serializedClass(null);
ExtendedHierarchicalStreamWriterHelper.startNode(
writer, name, Mapper.Null.class);
writer.endNode();
} else {
String name = mapper.serializedClass(item.getClass());
ExtendedHierarchicalStreamWriterHelper.startNode(
writer, name, item.getClass());
context.convertAnother(item);
writer.endNode();
}
}
};
}
protected void marshallField(final MarshallingContext context, Object newObj, Field field) {
context.convertAnother(
newObj, mapper.getLocalConverter(field.getDeclaringClass(), field.getName()));
}
public Object unmarshal(final HierarchicalStreamReader reader,
final UnmarshallingContext context) {
Object result = instantiateNewInstance(reader, context);
result = doUnmarshal(result, reader, context);
return serializationMembers.callReadResolve(result);
}
public Object doUnmarshal(final Object result, final HierarchicalStreamReader reader,
final UnmarshallingContext context) {
final Class resultType = result.getClass();
final Set seenFields = new HashSet() {
public boolean add(Object e) {
if (!super.add(e)) {
throw new DuplicateFieldException(((FastField)e).getName());
}
return true;
}
};
// process attributes before recursing into child elements.
Iterator it = reader.getAttributeNames();
while (it.hasNext()) {
String attrAlias = (String)it.next();
// TODO: realMember should return FastField
String attrName = mapper
.realMember(resultType, mapper.attributeForAlias(attrAlias));
Field field = reflectionProvider.getFieldOrNull(resultType, attrName);
if (field != null && shouldUnmarshalField(field)) {
Class classDefiningField = field.getDeclaringClass();
if (!mapper.shouldSerializeMember(classDefiningField, attrName)) {
continue;
}
// we need a converter that produces a string representation only
SingleValueConverter converter = mapper.getConverterFromAttribute(
classDefiningField, attrName, field.getType());
Class type = field.getType();
if (converter != null) {
Object value = converter.fromString(reader.getAttribute(attrAlias));
if (type.isPrimitive()) {
type = Primitives.box(type);
}
if (value != null && !type.isAssignableFrom(value.getClass())) {
ConversionException exception = new ConversionException("Cannot convert type");
exception.add("source-type", value.getClass().getName());
exception.add("target-type", type.getName());
throw exception;
}
seenFields.add(new FastField(classDefiningField, attrName));
reflectionProvider.writeField(result, attrName, value, classDefiningField);
}
}
}
Map implicitCollectionsForCurrentObject = null;
while (reader.hasMoreChildren()) {
reader.moveDown();
String originalNodeName = reader.getNodeName();
Class explicitDeclaringClass = readDeclaringClass(reader);
Class fieldDeclaringClass = explicitDeclaringClass == null
? resultType
: explicitDeclaringClass;
String fieldName = mapper.realMember(fieldDeclaringClass, originalNodeName);
Mapper.ImplicitCollectionMapping implicitCollectionMapping = mapper
.getImplicitCollectionDefForFieldName(fieldDeclaringClass, fieldName);
final Object value;
String implicitFieldName = null;
Field field = null;
Class type = null;
if (implicitCollectionMapping == null) {
// no item of an implicit collection for this name ... do we have a field?
field = reflectionProvider.getFieldOrNull(fieldDeclaringClass, fieldName);
if (field == null) {
// it is not a field ... do we have a field alias?
Class itemType = mapper.getItemTypeForItemFieldName(fieldDeclaringClass, fieldName);
if (itemType != null) {
String classAttribute = HierarchicalStreams.readClassAttribute(
reader, mapper);
if (classAttribute != null) {
type = mapper.realClass(classAttribute);
} else {
type = itemType;
}
} else {
// it is not an alias ... do we have an element of an implicit
// collection based on type only?
try {
type = mapper.realClass(originalNodeName);
implicitFieldName = mapper.getFieldNameForItemTypeAndName(
fieldDeclaringClass, type, originalNodeName);
} catch (CannotResolveClassException e) {
// type stays null ...
}
if (type == null || (type != null && implicitFieldName == null)) {
// either not a type or element is a type alias, but does not
// belong to an implicit field
handleUnknownField(
explicitDeclaringClass, fieldName, fieldDeclaringClass, originalNodeName);
// element is unknown in declaring class, ignore it now
type = null;
}
}
if (type == null) {
// no type, no value
value = null;
} else {
if (Map.Entry.class.equals(type)) {
// it is an element of an implicit map with two elements now for
// key and value
reader.moveDown();
final Object key = context.convertAnother(
result, HierarchicalStreams.readClassType(reader, mapper));
reader.moveUp();
reader.moveDown();
final Object v = context.convertAnother(
result, HierarchicalStreams.readClassType(reader, mapper));
reader.moveUp();
value = Collections.singletonMap(key, v)
.entrySet().iterator().next();
} else {
// recurse info hierarchy
value = context.convertAnother(result, type);
}
}
} else {
boolean fieldAlreadyChecked = false;
// we have a field, but do we have to address a hidden one?
if (explicitDeclaringClass == null) {
while (field != null
&& !(fieldAlreadyChecked = shouldUnmarshalField(field)
&& mapper.shouldSerializeMember(
field.getDeclaringClass(), fieldName))) {
field = reflectionProvider.getFieldOrNull(field
.getDeclaringClass()
.getSuperclass(), fieldName);
}
}
if (field != null
&& (fieldAlreadyChecked || (shouldUnmarshalField(field) && mapper
.shouldSerializeMember(field.getDeclaringClass(), fieldName)))) {
String classAttribute = HierarchicalStreams.readClassAttribute(
reader, mapper);
if (classAttribute != null) {
type = mapper.realClass(classAttribute);
} else {
type = mapper.defaultImplementationOf(field.getType());
}
// TODO the reflection provider should already return the proper field
value = unmarshallField(context, result, type, field);
Class definedType = field.getType();
if (!definedType.isPrimitive()) {
type = definedType;
}
} else {
value = null;
}
}
} else {
// we have an implicit collection with defined names
implicitFieldName = implicitCollectionMapping.getFieldName();
type = implicitCollectionMapping.getItemType();
if (type == null) {
String classAttribute = HierarchicalStreams.readClassAttribute(
reader, mapper);
type = mapper.realClass(classAttribute != null
? classAttribute
: originalNodeName);
}
value = context.convertAnother(result, type);
}
if (value != null && !type.isAssignableFrom(value.getClass())) {
throw new ConversionException("Cannot convert type "
+ value.getClass().getName()
+ " to type "
+ type.getName());
}
if (field != null) {
reflectionProvider.writeField(result, fieldName, value, field.getDeclaringClass());
seenFields.add(new FastField(field.getDeclaringClass(), fieldName));
} else if (type != null) {
if (implicitFieldName == null) {
// look for implicit field
implicitFieldName = mapper.getFieldNameForItemTypeAndName(
fieldDeclaringClass,
value != null ? value.getClass() : Mapper.Null.class,
originalNodeName);
}
if (implicitCollectionsForCurrentObject == null) {
implicitCollectionsForCurrentObject = new HashMap();
}
writeValueToImplicitCollection(
value, implicitCollectionsForCurrentObject, result, new FieldLocation(
implicitFieldName, fieldDeclaringClass));
}
reader.moveUp();
}
if (implicitCollectionsForCurrentObject != null) {
for (Iterator iter = implicitCollectionsForCurrentObject.entrySet().iterator(); iter
.hasNext();) {
Map.Entry entry = (Map.Entry)iter.next();
Object value = entry.getValue();
if (value instanceof ArraysList) {
Object array = ((ArraysList)value).toPhysicalArray();
final FieldLocation fieldLocation = (FieldLocation)entry.getKey();
final Field field = reflectionProvider.getFieldOrNull(fieldLocation.definedIn,
fieldLocation.fieldName);
reflectionProvider.writeField(result, fieldLocation.fieldName, array, field != null
? field.getDeclaringClass()
: null);
}
}
}
return result;
}
protected Object unmarshallField(final UnmarshallingContext context, final Object result,
Class type, Field field) {
return context.convertAnother(
result, type, mapper.getLocalConverter(field.getDeclaringClass(), field.getName()));
}
protected boolean shouldUnmarshalTransientFields() {
return false;
}
protected boolean shouldUnmarshalField(Field field) {
return !(Modifier.isTransient(field.getModifiers()) && !shouldUnmarshalTransientFields());
}
private void handleUnknownField(Class classDefiningField, String fieldName,
Class resultType, String originalNodeName) {
if (classDefiningField == null) {
for (Class cls = resultType; cls != null; cls = cls.getSuperclass()) {
if (!mapper.shouldSerializeMember(cls, originalNodeName)) {
return;
}
}
}
throw new UnknownFieldException(resultType.getName(), fieldName);
}
private void writeValueToImplicitCollection(Object value, Map implicitCollections, Object result, final FieldLocation fieldLocation) {
Collection collection = (Collection)implicitCollections.get(fieldLocation);
if (collection == null) {
final Field field = reflectionProvider.getFieldOrNull(fieldLocation.definedIn, fieldLocation.fieldName);
Class physicalFieldType = field != null
? field.getType()
: reflectionProvider.getFieldType(result, fieldLocation.fieldName, null);
if (physicalFieldType.isArray()) {
collection = new ArraysList(physicalFieldType);
} else {
Class fieldType = mapper.defaultImplementationOf(physicalFieldType);
if (!(Collection.class.isAssignableFrom(fieldType) || Map.class
.isAssignableFrom(fieldType))) {
ObjectAccessException oaex = new ObjectAccessException(
"Field is configured for an implicit Collection or Map, but is of an incompatible type");
oaex.add("field", result.getClass().getName() + "."+fieldLocation.fieldName);
oaex.add("field-type", fieldType.getName());
throw oaex;
}
if (pureJavaReflectionProvider == null) {
pureJavaReflectionProvider = new PureJavaReflectionProvider();
}
Object instance = pureJavaReflectionProvider.newInstance(fieldType);
if (instance instanceof Collection) {
collection = (Collection)instance;
} else {
Mapper.ImplicitCollectionMapping implicitCollectionMapping = mapper
.getImplicitCollectionDefForFieldName(fieldLocation.definedIn, fieldLocation.fieldName);
collection = new MappingList(
(Map)instance, implicitCollectionMapping.getKeyFieldName());
}
reflectionProvider.writeField(result, fieldLocation.fieldName, instance, field != null
? field.getDeclaringClass()
: null);
}
implicitCollections.put(fieldLocation, collection);
}
collection.add(value);
}
private Class readDeclaringClass(HierarchicalStreamReader reader) {
String attributeName = mapper.aliasForSystemAttribute("defined-in");
String definedIn = attributeName == null ? null : reader.getAttribute(attributeName);
return definedIn == null ? null : mapper.realClass(definedIn);
}
protected Object instantiateNewInstance(HierarchicalStreamReader reader,
UnmarshallingContext context) {
String attributeName = mapper.aliasForSystemAttribute("resolves-to");
String readResolveValue = attributeName == null ? null : reader
.getAttribute(attributeName);
Object currentObject = context.currentObject();
if (currentObject != null) {
return currentObject;
} else if (readResolveValue != null) {
return reflectionProvider.newInstance(mapper.realClass(readResolveValue));
} else {
return reflectionProvider.newInstance(context.getRequiredType());
}
}
public void flushCache() {
serializationMethodInvoker.flushCache();
}
protected Object readResolve() {
serializationMethodInvoker = new SerializationMethodInvoker();
serializationMembers = serializationMethodInvoker.serializationMembers;
return this;
}
public static class DuplicateFieldException extends ConversionException {
public DuplicateFieldException(String msg) {
super("Duplicate field " + msg);
add("field", msg);
}
}
public static class UnknownFieldException extends ConversionException {
public UnknownFieldException(String type, String field) {
super("No such field " + type + "." + field);
add("field", field);
}
}
private static class FieldLocation {
final String fieldName;
final Class definedIn;
FieldLocation(final String fieldName, final Class definedIn) {
this.fieldName = fieldName;
this.definedIn = definedIn;
}
public int hashCode() {
final int prime = 7;
int result = 1;
result = prime * result + (definedIn == null ? 0 : definedIn.getName().hashCode());
result = prime * result + (fieldName == null ? 0 : fieldName.hashCode());
return result;
}
public boolean equals(final Object obj) {
if (this == obj) {
return true;
}
if (obj == null) {
return false;
}
if (getClass() != obj.getClass()) {
return false;
}
final FieldLocation other = (FieldLocation)obj;
if (definedIn != other.definedIn) {
return false;
}
if (fieldName == null) {
if (other.fieldName != null) {
return false;
}
} else if (!fieldName.equals(other.fieldName)) {
return false;
}
return true;
}
}
private static class FieldInfo extends FieldLocation {
final Class type;
final Object value;
FieldInfo(final String fieldName, final Class type, final Class definedIn, final Object value) {
super(fieldName, definedIn);
this.type = type;
this.value = value;
}
}
private static class ArraysList extends ArrayList {
final Class physicalFieldType;
ArraysList(Class physicalFieldType) {
this.physicalFieldType = physicalFieldType;
}
Object toPhysicalArray() {
Object[] objects = toArray();
Object array = Array.newInstance(
physicalFieldType.getComponentType(), objects.length);
if (physicalFieldType.getComponentType().isPrimitive()) {
for (int i = 0; i < objects.length; ++i) {
Array.set(array, i, Array.get(objects, i));
}
} else {
System.arraycopy(objects, 0, array, 0, objects.length);
}
return array;
}
}
private class MappingList extends AbstractList {
private final Map map;
private final String keyFieldName;
private final Map fieldCache = new HashMap();
public MappingList(Map map, String keyFieldName) {
this.map = map;
this.keyFieldName = keyFieldName;
}
public boolean add(Object object) {
if (object == null) {
boolean containsNull = !map.containsKey(null);
map.put(null, null);
return containsNull;
}
Class itemType = object.getClass();
if (keyFieldName != null) {
Field field = (Field)fieldCache.get(itemType);
if (field == null) {
field = reflectionProvider.getField(itemType, keyFieldName);
fieldCache.put(itemType, field);
}
if (field != null) {
Object key = Fields.read(field, object);
return map.put(key, object) == null;
}
} else if (object instanceof Map.Entry) {
final Map.Entry entry = (Map.Entry)object;
return map.put(entry.getKey(), entry.getValue()) == null;
}
ConversionException exception =
new ConversionException("Element is not defined as entry for implicit map");
exception.add("map-type", map.getClass().getName());
exception.add("element-type", object.getClass().getName());
throw exception;
}
public Object get(int index) {
throw new UnsupportedOperationException();
}
public int size() {
return map.size();
}
}
}
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