Many resources are needed to download a project. Please understand that we have to compensate our server costs. Thank you in advance. Project price only 1 $
You can buy this project and download/modify it how often you want.
/*
* ReadGraph.java April 2007
*
* Copyright (C) 2007, Niall Gallagher
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General
* Public License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place, Suite 330,
* Boston, MA 02111-1307 USA
*/
package org.simpleframework.xml.strategy;
import org.simpleframework.xml.stream.NodeMap;
import org.simpleframework.xml.stream.Node;
import java.util.HashMap;
/**
* The ReadGraph object is used to build a graph of the
* objects that have been deserialized from the XML document. This is
* required so that cycles in the object graph can be recreated such
* that the deserialized object is an exact duplicate of the object
* that was serialized. Objects are stored in the graph using unique
* keys, which for this implementation are unique strings.
*
* @author Niall Gallagher
*
* @see org.simpleframework.xml.strategy.WriteGraph
*/
class ReadGraph extends HashMap {
/**
* This is the class loader that is used to load the types used.
*/
private ClassLoader loader;
/**
* This is used to represent the length of array object values.
*/
private String length;
/**
* This is the label used to mark the type of an object.
*/
private String label;
/**
* This is the attribute used to mark the identity of an object.
*/
private String mark;
/**
* This is the attribute used to refer to an existing instance.
*/
private String refer;
/**
* Constructor for the ReadGraph object. This is used
* to create graphs that are used for reading objects from the XML
* document. The specified strategy is used to acquire the names
* of the special attributes used during the serialization.
*
* @param contract this is the name scheme used by the strategy
* @param loader this is the class loader to used for the graph
*/
public ReadGraph(Contract contract, ClassLoader loader) {
this.refer = contract.getReference();
this.mark = contract.getIdentity();
this.length = contract.getLength();
this.label = contract.getLabel();
this.loader = loader;
}
/**
* This is used to recover the object references from the document
* using the special attributes specified. This allows the element
* specified by the NodeMap to be used to discover
* exactly which node in the object graph the element represents.
*
* @param field the type of the field or method in the instance
* @param node this is the XML element to be deserialized
*
* @return this is used to return the type to acquire the value
*/
public Value getElement(Class field, NodeMap node) throws Exception {
Node entry = node.remove(label);
Class type = field;
if(field.isArray()) {
type = field.getComponentType();
}
if(entry != null) {
String name = entry.getValue();
type = loader.loadClass(name);
}
return getInstance(field, type, node);
}
/**
* This is used to recover the object references from the document
* using the special attributes specified. This allows the element
* specified by the NodeMap to be used to discover
* exactly which node in the object graph the element represents.
*
* @param field the type of the field or method in the instance
* @param real this is the overridden type from the XML element
* @param node this is the XML element to be deserialized
*
* @return this is used to return the type to acquire the value
*/
private Value getInstance(Class field, Class real, NodeMap node) throws Exception {
Node entry = node.remove(mark);
if(entry == null) {
return getReference(field, real, node);
}
String key = entry.getValue();
if(containsKey(key)) {
throw new CycleException("Element '%s' already exists", key);
}
return getValue(field, real, node, key);
}
/**
* This is used to recover the object references from the document
* using the special attributes specified. This allows the element
* specified by the NodeMap to be used to discover
* exactly which node in the object graph the element represents.
*
* @param field the type of the field or method in the instance
* @param real this is the overridden type from the XML element
* @param node this is the XML element to be deserialized
*
* @return this is used to return the type to acquire the value
*/
private Value getReference(Class field, Class real, NodeMap node) throws Exception {
Node entry = node.remove(refer);
if(entry == null) {
return getValue(field, real, node);
}
String key = entry.getValue();
Object value = get(key);
if(!containsKey(key)) {
throw new CycleException("Invalid reference '%s' found", key);
}
return new Reference(value, real);
}
/**
* This is used to acquire the Value which can be used
* to represent the deserialized value. The type create cab be
* added to the graph of created instances if the XML element has
* an identification attribute, this allows cycles to be completed.
*
* @param field the type of the field or method in the instance
* @param real this is the overridden type from the XML element
* @param node this is the XML element to be deserialized
*
* @return this is used to return the type to acquire the value
*/
private Value getValue(Class field, Class real, NodeMap node) throws Exception {
if(field.isArray()) {
return getArray(field, real, node);
}
return new ObjectValue(real);
}
/**
* This is used to acquire the Value which can be used
* to represent the deserialized value. The type create cab be
* added to the graph of created instances if the XML element has
* an identification attribute, this allows cycles to be completed.
*
* @param field the type of the field or method in the instance
* @param real this is the overridden type from the XML element
* @param node this is the XML element to be deserialized
* @param key the key the instance is known as in the graph
*
* @return this is used to return the type to acquire the value
*/
private Value getValue(Class field, Class real, NodeMap node, String key) throws Exception {
Value type = getValue(field, real, node);
if(key != null) {
return new Allocate(type, this, key);
}
return type;
}
/**
* This is used to acquire the Value which can be used
* to represent the deserialized value. The type create cab be
* added to the graph of created instances if the XML element has
* an identification attribute, this allows cycles to be completed.
*
* @param field the type of the field or method in the instance
* @param real this is the overridden type from the XML element
* @param node this is the XML element to be deserialized
*
* @return this is used to return the type to acquire the value
*/
private Value getArray(Class field, Class real, NodeMap node) throws Exception {
Node entry = node.remove(length);
int size = 0;
if(entry != null) {
String value = entry.getValue();
size = Integer.parseInt(value);
}
return new ArrayValue(real, size);
}
}
