/*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/*
* XMLSerializationMethodHandler.java
* Copyright (C) 2004-2012 University of Waikato, Hamilton, New Zealand
*
*/
package weka.core.xml;
import java.lang.reflect.Method;
import org.w3c.dom.Element;
import weka.core.RevisionHandler;
import weka.core.RevisionUtils;
/**
* This class handles relationships between display names of properties
* (or classes) and Methods that are associated with them. It differentiates
* between read and write methods. It automatically stores public methods that
* have the same signature as the <code>readFromXML()</code> and
* <code>writeToXML()</code> methods in the <code>XMLSerialization</code>
* class.
*
* @see MethodHandler
* @see XMLSerialization
*
* @author FracPete (fracpete at waikato dot ac dot nz)
* @version $Revision: 8034 $
*/
public class XMLSerializationMethodHandler
implements RevisionHandler {
/** for storing read methods */
protected MethodHandler m_ReadMethods = null;
/** for storing write methods */
protected MethodHandler m_WriteMethods = null;
/** the object to retrieve the methods from */
protected Object owner = null;
/**
* initializes the method handling, executes also <code>clear()</code>, which
* adds initial methods automatically.
*
* @param owner the owner to retrieve the methods from
* @throws Exception if initialization fails
* @see #clear()
*/
public XMLSerializationMethodHandler(Object owner) throws Exception {
super();
this.owner = owner;
m_ReadMethods = new MethodHandler();
m_WriteMethods = new MethodHandler();
clear();
}
/**
* adds all methods that are like <code>template</code> to the method list
*
* @param handler the list to add fitting methods to
* @param template the signature to check the given methods against
* @param methods the methods to check
*/
protected void addMethods(MethodHandler handler, Method template, Method[] methods) {
int i;
int n;
Method method;
boolean equal;
String name;
for (i = 0; i < methods.length; i++) {
method = methods[i];
// is it template?
if (template.equals(method))
continue;
// tests
// 1. return type
if (!template.getReturnType().equals(method.getReturnType()))
continue;
// 2. signature
if (template.getParameterTypes().length != method.getParameterTypes().length)
continue;
equal = true;
for (n = 0; n < template.getParameterTypes().length; n++) {
if (!template.getParameterTypes()[n].equals(method.getParameterTypes()[n])) {
equal = false;
break;
}
}
// add to list
if (equal) {
name = method.getName();
name = name.replaceAll("read|write", "");
name = name.substring(0, 1).toLowerCase() + name.substring(1);
handler.add(name, method);
}
}
}
/**
* automatically adds all fitting methods to the custom read/write lists,
* it excludes only the generic ones. it is automatically called in
* <code>clear()</code>
* It only work with methods that apply to the naming rule "read" + property
* name (same for "write")
*
* @throws Exception if retrieving of methods fails
* @see #clear()
*/
protected void addMethods() throws Exception {
Method method;
Class[] params;
// read
params = new Class[1];
params[0] = Element.class;
method = owner.getClass().getMethod("readFromXML", params);
addMethods(m_ReadMethods, method, owner.getClass().getMethods());
// write
params = new Class[3];
params[0] = Element.class;
params[1] = Object.class;
params[2] = String.class;
method = owner.getClass().getMethod("writeToXML", params);
addMethods(m_WriteMethods, method, owner.getClass().getMethods());
}
/**
* returns the method with the given name that has the same signature as
* <code>readFromXML()</code> of the <code>XMLSerialiation</code> class.
* simplifies the adding of custom methods.
*
* @param o the object to inspect
* @param name the name of the method to return
* @return either <code>null</code> if no method was found or a reference
* @see XMLSerialization#readFromXML(Element)
*/
public static Method findReadMethod(Object o, String name) {
Class[] params;
Method result;
result = null;
params = new Class[1];
params[0] = Element.class;
try {
result = o.getClass().getMethod(name, params);
}
catch (Exception e) {
result = null;
}
return result;
}
/**
* returns the method with the given name that has the same signature as
* <code>writeToXML()</code> of the <code>XMLSerialiation</code> class.
* simplifies the adding of custom methods.
*
* @param o the object to inspect
* @param name the name of the method to return
* @return either <code>null</code> if no method was found or a reference
* @see XMLSerialization#writeToXML(Element, Object, String)
*/
public static Method findWriteMethod(Object o, String name) {
Class[] params;
Method result;
result = null;
params = new Class[3];
params[0] = Element.class;
params[1] = Object.class;
params[2] = String.class;
try {
result = o.getClass().getMethod(name, params);
}
catch (Exception e) {
result = null;
}
return result;
}
/**
* removes all current methods and adds the methods according to the
*
*/
public void clear() {
m_ReadMethods.clear();
m_WriteMethods.clear();
try {
addMethods();
}
catch (Exception e) {
e.printStackTrace();
}
}
/**
* returns the handler for read methods
*
* @return the methodhandler for read methods
*/
public MethodHandler read() {
return m_ReadMethods;
}
/**
* returns the handler for write methods
*
* @return the methodhandler for read methods
*/
public MethodHandler write() {
return m_WriteMethods;
}
/**
* adds read and write methods for the given class, i.e., read&;lt;name>
* and write<name> ("name" is prefixed by read and write)
*
* @param handler the handler class that contains the read and write method
* @param cls the class to register the read and write method for
* @param name the suffix of the read and write method
*/
public void register(Object handler, Class cls, String name) {
read().add(cls, XMLSerializationMethodHandler.findReadMethod(handler, "read" + name));
write().add(cls, XMLSerializationMethodHandler.findWriteMethod(handler, "write" + name));
}
/**
* returns the read and write method handlers as string
*
* @return the read/write method handlers as string
*/
public String toString() {
return "Read Methods:\n" + read() + "\n\n" + "Write Methods:\n" + write();
}
/**
* Returns the revision string.
*
* @return the revision
*/
public String getRevision() {
return RevisionUtils.extract("$Revision: 8034 $");
}
}