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feilong is a suite of core and expanded libraries that include utility classes, http, excel,cvs, io classes, and much much more.
/*
* Copyright (C) 2006, 2007, 2008, 2011, 2015, 2018 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 15. March 2007 by Joerg Schaible
*/
package com.feilong.lib.xstream.core;
import java.util.HashMap;
import java.util.Map;
import com.feilong.lib.xstream.converters.ConversionException;
import com.feilong.lib.xstream.converters.Converter;
import com.feilong.lib.xstream.converters.ConverterLookup;
import com.feilong.lib.xstream.core.util.FastStack;
import com.feilong.lib.xstream.io.HierarchicalStreamReader;
import com.feilong.lib.xstream.mapper.Mapper;
/**
* Abstract base class for a TreeUnmarshaller, that resolves references.
*
* @author Joe Walnes
* @author Jörg Schaible
* @author Mauro Talevi
* @since 1.2
*/
public abstract class AbstractReferenceUnmarshaller extends TreeUnmarshaller{
private static final Object NULL = new Object();
private Map values = new HashMap();
private FastStack parentStack = new FastStack(16);
public AbstractReferenceUnmarshaller(Object root, HierarchicalStreamReader reader, ConverterLookup converterLookup, Mapper mapper){
super(root, reader, converterLookup, mapper);
}
@Override
protected Object convert(Object parent,Class type,Converter converter){
if (parentStack.size() > 0){ // handles circular references
Object parentReferenceKey = parentStack.peek();
if (parentReferenceKey != null){
if (!values.containsKey(parentReferenceKey)){ // see AbstractCircularReferenceTest.testWeirdCircularReference()
values.put(parentReferenceKey, parent);
}
}
}
final Object result;
final String attributeName = getMapper().aliasForSystemAttribute("reference");
final String reference = attributeName == null ? null : reader.getAttribute(attributeName);
final boolean isReferenceable = getMapper().isReferenceable(type);
if (reference != null){
final Object cache = isReferenceable ? values.get(getReferenceKey(reference)) : null;
if (cache == null){
final ConversionException ex = new ConversionException("Invalid reference");
ex.add("reference", reference);
ex.add("referenced-type", type.getName());
ex.add("referenceable", Boolean.toString(isReferenceable));
throw ex;
}
result = cache == NULL ? null : cache;
}else if (!isReferenceable){
result = super.convert(parent, type, converter);
}else{
Object currentReferenceKey = getCurrentReferenceKey();
parentStack.push(currentReferenceKey);
Object localResult = null;
try{
localResult = super.convert(parent, type, converter);
}finally{
result = localResult;
if (currentReferenceKey != null){
values.put(currentReferenceKey, result == null ? NULL : result);
}
parentStack.popSilently();
}
}
return result;
}
protected abstract Object getReferenceKey(String reference);
protected abstract Object getCurrentReferenceKey();
}