/*
* Copyright 2005 Joe Walker
*
* 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.directwebremoting.dwrp;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.directwebremoting.extend.Converter;
import org.directwebremoting.extend.ConverterManager;
import org.directwebremoting.extend.InboundContext;
import org.directwebremoting.extend.InboundVariable;
import org.directwebremoting.extend.MarshallException;
import org.directwebremoting.extend.NamedConverter;
import org.directwebremoting.extend.NonNestedOutboundVariable;
import org.directwebremoting.extend.OutboundContext;
import org.directwebremoting.extend.OutboundVariable;
import org.directwebremoting.extend.TypeHintContext;
import org.directwebremoting.util.LocalUtil;
import org.directwebremoting.util.Messages;
/**
* A class to manage the converter types and the instantiated class name matches.
* @author Joe Walker [joe at getahead dot ltd dot uk]
*/
public class DefaultConverterManager implements ConverterManager
{
/* (non-Javadoc)
* @see org.directwebremoting.ConverterManager#addConverterType(java.lang.String, java.lang.String)
*/
public void addConverterType(String id, String className)
{
if (!LocalUtil.isJavaIdentifier(id))
{
log.error("Illegal identifier: '" + id + "'");
return;
}
Class<? extends Converter> clazz = LocalUtil.classForName(id, className, Converter.class);
if (clazz != null)
{
log.debug("- adding converter type: " + id + " = " + clazz.getName());
converterTypes.put(id, clazz);
}
}
/* (non-Javadoc)
* @see org.directwebremoting.ConverterManager#addConverter(java.lang.String, java.lang.String, java.util.Map)
*/
public void addConverter(String match, String type, Map<String, String> params) throws IllegalArgumentException, InstantiationException, IllegalAccessException
{
Class<?> clazz = converterTypes.get(type);
if (clazz == null)
{
log.info("Probably not an issue: " + match + " is not available so the " + type + " converter will not load. This is only an problem if you wanted to use it.");
return;
}
Converter converter = (Converter) clazz.newInstance();
LocalUtil.setParams(converter, params, ignore);
// add the converter for the specified match
addConverter(match, converter);
}
/* (non-Javadoc)
* @see org.directwebremoting.ConverterManager#addConverter(java.lang.String, org.directwebremoting.Converter)
*/
public void addConverter(String match, Converter converter) throws IllegalArgumentException
{
// Check that we don't have this one already
Converter other = converters.get(match);
if (other != null)
{
log.warn("Clash of converters for " + match + ". Using " + converter.getClass().getName() + " in place of " + other.getClass().getName());
}
log.debug("- adding converter: " + converter.getClass().getSimpleName() + " for " + match);
converter.setConverterManager(this);
converters.put(match, converter);
}
/* (non-Javadoc)
* @see org.directwebremoting.ConverterManager#getConverterMatchStrings()
*/
public Collection<String> getConverterMatchStrings()
{
return Collections.unmodifiableSet(converters.keySet());
}
/* (non-Javadoc)
* @see org.directwebremoting.ConverterManager#getConverterByMatchString(java.lang.String)
*/
public Converter getConverterByMatchString(String match)
{
return converters.get(match);
}
/* (non-Javadoc)
* @see org.directwebremoting.ConverterManager#isConvertable(java.lang.Class)
*/
public boolean isConvertable(Class<?> paramType)
{
return getConverter(paramType) != null;
}
/* (non-Javadoc)
* @see org.directwebremoting.ConverterManager#convertInbound(java.lang.Class, org.directwebremoting.InboundVariable, org.directwebremoting.InboundContext, org.directwebremoting.TypeHintContext)
*/
public Object convertInbound(Class<?> paramType, InboundVariable data, InboundContext inctx, TypeHintContext incc) throws MarshallException
{
Object converted = inctx.getConverted(data, paramType);
if (converted == null)
{
Converter converter = null;
// Was the inbound variable marshalled as an Object in the client
// (could mean that this is an instance of one of our generated
// JavaScript classes)
String type = data.getNamedObjectType();
if (type != null)
{
converter = getNamedConverter(paramType, type);
}
// Fall back to the standard way of locating a converter if we
// didn't find anything above
if (converter == null)
{
converter = getConverter(paramType);
}
if (converter == null)
{
throw new MarshallException(paramType, Messages.getString("DefaultConverterManager.MissingConverter", paramType));
}
// We only think about doing a null conversion ourselves once we are
// sure that there is a converter available. This prevents hackers
// from passing null to things they are not allowed to convert
if (data.isNull())
{
return null;
}
inctx.pushContext(incc);
converted = converter.convertInbound(paramType, data, inctx);
inctx.popContext();
}
return converted;
}
/* (non-Javadoc)
* @see org.directwebremoting.ConverterManager#convertOutbound(java.lang.Object, org.directwebremoting.OutboundContext)
*/
public OutboundVariable convertOutbound(Object data, OutboundContext converted) throws MarshallException
{
if (data == null)
{
return new NonNestedOutboundVariable("null");
}
// Check to see if we have done this one already
OutboundVariable ov = converted.get(data);
if (ov != null)
{
// So the object as been converted already, we just need to refer to it.
return ov.getReferenceVariable();
}
// So we will have to do the conversion
Converter converter = getConverter(data);
if (converter == null)
{
String message = Messages.getString("DefaultConverterManager.MissingConverter", data.getClass().getName());
log.error(message);
return new ErrorOutboundVariable(message);
}
return converter.convertOutbound(data, converted);
}
/* (non-Javadoc)
* @see org.directwebremoting.ConverterManager#setExtraTypeInfo(org.directwebremoting.TypeHintContext, java.lang.Class)
*/
public void setExtraTypeInfo(TypeHintContext thc, Class<?> type)
{
extraTypeInfoMap.put(thc, type);
}
/* (non-Javadoc)
* @see org.directwebremoting.ConverterManager#getExtraTypeInfo(org.directwebremoting.TypeHintContext)
*/
public Class<?> getExtraTypeInfo(TypeHintContext thc)
{
return extraTypeInfoMap.get(thc);
}
/* (non-Javadoc)
* @see org.directwebremoting.ConverterManager#setConverters(java.util.Map)
*/
public void setConverters(Map<String, Converter> converters)
{
this.converters = converters;
}
/**
* Like <code>getConverter(object.getClass());</code> except that since the
* object can be null we check for that fist and then do a lookup against
* the <code>Void.TYPE</code> converter
* @param object The object to find a converter for
* @return The converter for the given type
*/
private Converter getConverter(Object object)
{
if (object == null)
{
return getConverter(Void.TYPE);
}
return getConverter(object.getClass());
}
/**
* When we are using typed Javascript names we sometimes want to get a
* specially named converter
* @param paramType The class that we are converting to
* @param javascriptClassName The type name as passed in from the client
* @return The Converter that matches this request (if any)
* @throws MarshallException IF marshalling fails
*/
protected Converter getNamedConverter(Class<?> paramType, String javascriptClassName) throws MarshallException
{
// Locate a converter for this JavaScript classname
for (Map.Entry<String, Converter> entry : converters.entrySet())
{
String match = entry.getKey();
Converter conv = entry.getValue();
// JavaScript mapping is only applicable for compound converters
if (conv instanceof NamedConverter)
{
NamedConverter boConv = (NamedConverter) conv;
if (boConv.getJavascript() != null && boConv.getJavascript().equals(javascriptClassName))
{
// We found a potential converter! But is the converter's
// Java class compatible with the parameter type?
try
{
Class<?> inboundClass = LocalUtil.classForName(match);
if (paramType.isAssignableFrom(inboundClass))
{
// Hack: We also want to make sure that the
// converter creates its object based on the inbound
// class instead of the parameter type, and we have
// to use the other reference for this:
boConv.setInstanceType(inboundClass);
return boConv;
}
}
catch (ClassNotFoundException ex)
{
throw new MarshallException(paramType, ex);
}
}
}
}
return null;
}
/**
* @param paramType The type to find a converter for
* @return The converter for the given type, or null if one can't be found
*/
private Converter getConverter(Class<?> paramType)
{
// Can we find a converter assignable to paramType in the HashMap?
Converter converter = getConverterAssignableFrom(paramType);
if (converter != null)
{
return converter;
}
String lookup = paramType.getName();
// Before we start trying for a match on package parts we check for
// dynamic proxies
if (lookup.startsWith("$Proxy"))
{
converter = converters.get("$Proxy*");
if (converter != null)
{
return converter;
}
}
while (true)
{
// Can we find a converter using wildcards?
converter = converters.get(lookup + ".*");
if (converter != null)
{
return converter;
}
// Arrays can have wildcards like [L* so we don't require a '.'
converter = converters.get(lookup + '*');
if (converter != null)
{
return converter;
}
// Give up if the name is now empty
if (lookup.length() == 0)
{
break;
}
// Strip of the component after the last .
int lastdot = lookup.lastIndexOf('.');
if (lastdot != -1)
{
lookup = lookup.substring(0, lastdot);
}
else
{
int arrayMarkers = 0;
while (lookup.charAt(arrayMarkers) == '[')
{
arrayMarkers++;
}
if (arrayMarkers == 0)
{
// so we are out of dots and out of array markers
// bail out.
break;
}
// We want to keep the type marker too
lookup = lookup.substring(arrayMarkers - 1, arrayMarkers + 1);
// Now can we find it?
converter = converters.get(lookup);
if (converter != null)
{
return converter;
}
}
}
return null;
}
/**
* @param paramType The type to find a converter for
* @return The converter assignable for the given type, or null if one can't be found
*/
private Converter getConverterAssignableFrom(Class<?> paramType)
{
if (paramType == null)
{
return null;
}
String lookup = paramType.getName();
// Can we find the converter for paramType in the converters HashMap?
Converter converter = converters.get(lookup);
if (converter != null)
{
return converter;
}
// Lookup all of the interfaces of this class for a match
for (Class<?> anInterface : paramType.getInterfaces())
{
converter = getConverterAssignableFrom(anInterface);
if (converter != null)
{
converters.put(lookup, converter);
return converter;
}
}
// Let's search it in paramType superClass
converter = getConverterAssignableFrom(paramType.getSuperclass());
if (converter != null)
{
converters.put(lookup, converter);
}
return converter;
}
/**
* Where we store real type information behind generic types
*/
protected Map<TypeHintContext, Class<?>> extraTypeInfoMap = new HashMap<TypeHintContext, Class<?>>();
/**
* The list of the available converters
*/
protected Map<String, Class<?>> converterTypes = new HashMap<String, Class<?>>();
/**
* The list of the configured converters
*/
protected Map<String, Converter> converters = new HashMap<String, Converter>();
/**
* The properties that we don't warn about if they don't exist.
* @see DefaultConverterManager#addConverter(String, String, Map)
*/
private static List<String> ignore = Arrays.asList("converter", "match");
/**
* The log stream
*/
private static final Log log = LogFactory.getLog(DefaultConverterManager.class);
}
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