/*
* 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.convert;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.StringTokenizer;
import java.util.TreeMap;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.directwebremoting.ConversionException;
import org.directwebremoting.extend.ConstructorProperty;
import org.directwebremoting.extend.ConvertUtil;
import org.directwebremoting.extend.ConverterManager;
import org.directwebremoting.extend.InboundContext;
import org.directwebremoting.extend.InboundVariable;
import org.directwebremoting.extend.NamedConverter;
import org.directwebremoting.extend.ObjectOutboundVariable;
import org.directwebremoting.extend.OutboundContext;
import org.directwebremoting.extend.OutboundVariable;
import org.directwebremoting.extend.Property;
import org.directwebremoting.extend.ProtocolConstants;
import org.directwebremoting.util.LocalUtil;
import org.directwebremoting.util.Pair;
/**
* BasicObjectConverter is a parent to {@link BeanConverter} and
* {@link ObjectConverter} an provides support for include and exclude lists,
* and instanceTypes.
* @author Joe Walker [joe at getahead dot ltd dot uk]
*/
public abstract class BasicObjectConverter implements NamedConverter
{
/* (non-Javadoc)
* @see org.directwebremoting.Converter#convertInbound(java.lang.Class, org.directwebremoting.InboundVariable, org.directwebremoting.InboundContext)
*/
public Object convertInbound(Class<?> paramType, InboundVariable data) throws ConversionException
{
if (data.isNull())
{
return null;
}
String value = data.getValue();
if (value == null)
{
throw new NullPointerException(data.toString());
}
// If the text is null then the whole bean is null
if (value.trim().equals(ProtocolConstants.INBOUND_NULL))
{
return null;
}
if (!value.startsWith(ProtocolConstants.INBOUND_MAP_START) || !value.endsWith(ProtocolConstants.INBOUND_MAP_END))
{
log.warn("Expected object while converting data for " + paramType.getName() + " in " + data.getContext().getCurrentProperty() + ". Passed: " + value);
throw new ConversionException(paramType, "Data conversion error. See logs for more details.");
}
value = value.substring(1, value.length() - 1);
try
{
// Loop through the properties passed in
Map<String, String> tokens = extractInboundTokens(paramType, value);
if (paramsString == null)
{
return createUsingSetterInjection(paramType, data, tokens);
}
else
{
return createUsingConstructorInjection(paramType, data, tokens);
}
}
catch (InvocationTargetException ex)
{
throw new ConversionException(paramType, ex.getTargetException());
}
catch (ConversionException ex)
{
throw ex;
}
catch (Exception ex)
{
throw new ConversionException(paramType, ex);
}
}
/**
* We're using constructor injection, create and populate a bean using
* a constructor
*/
private Object createUsingConstructorInjection(Class<?> paramType, InboundVariable data, Map<String, String> tokens) throws NoSuchMethodException, InstantiationException, IllegalAccessException, InvocationTargetException
{
Class<?> type;
if (instanceType != null)
{
type = instanceType;
}
else
{
type = paramType;
}
// Find a constructor to match
List<Class<?>> parameterTypes = new ArrayList<Class<?>>();
for (Pair<Class<?>, String> parameter : parameters)
{
parameterTypes.add(parameter.left);
}
Class<?>[] paramTypeArray = parameterTypes.toArray(new Class<?>[parameterTypes.size()]);
Constructor<?> constructor;
try
{
constructor = type.getConstructor(paramTypeArray);
}
catch (NoSuchMethodException ex)
{
log.error("Can't find a constructor for " + type.getName() + " with params " + parameterTypes);
throw ex;
}
List<Object> arguments = new ArrayList<Object>();
int paramNum = 0;
for (Pair<Class<?>, String> parameter : parameters)
{
String argument = tokens.get(parameter.right);
ConstructorProperty property = new ConstructorProperty(constructor, parameter.right, paramNum);
Object output = convert(argument, parameter.left, data.getContext(), property);
arguments.add(output);
paramNum++;
}
// log.debug("Using constructor injection for: " + constructor);
Object[] argArray = arguments.toArray(new Object[arguments.size()]);
try
{
return constructor.newInstance(argArray);
}
catch (InstantiationException ex)
{
log.error("Error building using constructor " + constructor.getName() + " with arguments " + argArray);
throw ex;
}
catch (IllegalAccessException ex)
{
log.error("Error building using constructor " + constructor.getName() + " with arguments " + argArray);
throw ex;
}
catch (InvocationTargetException ex)
{
log.error("Error building using constructor " + constructor.getName() + " with arguments " + argArray);
throw ex;
}
}
/**
* We're using setter injection, create and populate a bean using property
* setters
*/
private Object createUsingSetterInjection(Class<?> paramType, InboundVariable data, Map<String, String> tokens) throws InstantiationException, IllegalAccessException
{
Object bean;
if (instanceType != null)
{
bean = instanceType.newInstance();
}
else
{
bean = createParameterInstance(paramType);
}
// We should put the new object into the working map in case it
// is referenced later nested down in the conversion process.
if (instanceType != null)
{
data.getContext().addConverted(data, instanceType, bean);
}
else
{
data.getContext().addConverted(data, paramType, bean);
}
Map<String, Property> properties = getPropertyMapFromObject(bean, false, true);
for (Entry<String, String> entry : tokens.entrySet())
{
String key = entry.getKey();
// TODO: We don't URL decode method names we probably should. This is $dwr
// TODO: We should probably have stripped these out already
if (key.startsWith("%24dwr"))
{
continue;
}
Property property = properties.get(key);
if (property == null)
{
log.warn("Missing setter: " + paramType.getName() + ".set" + Character.toTitleCase(key.charAt(0)) + key.substring(1) + "() to match javascript property: " + key + ". Check include/exclude rules and overloaded methods.");
continue;
}
Object output = convert(entry.getValue(), property.getPropertyType(), data.getContext(), property);
property.setValue(bean, output);
}
return bean;
}
/**
* Extension point for subclasses to instantiate parameter classes.
*
* @param paramType The type of parameter that needs to be instantiated
* @return An instance of <code>paramType</code>
* @throws InstantiationException
* @throws IllegalAccessException
*/
protected Object createParameterInstance(Class<?> paramType) throws InstantiationException, IllegalAccessException
{
return paramType.newInstance();
}
/**
* We have inbound data and a type that we need to convert it into, this
* method performs the conversion.
*/
protected Object convert(String val, Class<?> propType, InboundContext inboundContext, Property property)
{
String[] split = ConvertUtil.splitInbound(val);
String splitValue = split[ConvertUtil.INBOUND_INDEX_VALUE];
String splitType = split[ConvertUtil.INBOUND_INDEX_TYPE];
InboundVariable nested = new InboundVariable(inboundContext, null, splitType, splitValue);
nested.dereference();
Property incc = createTypeHintContext(inboundContext, property);
return converterManager.convertInbound(propType, nested, incc);
}
/**
* {@link #convertInbound} needs to create a {@link Property} for the
* {@link Property} it is converting so that the type guessing system can do
* its work.
* <p>The method of generating a {@link Property} is different for
* the {@link BeanConverter} and the {@link ObjectConverter}.
* @param inctx The parent context
* @param property The property being converted
* @return The new TypeHintContext
*/
protected abstract Property createTypeHintContext(InboundContext inctx, Property property);
/* (non-Javadoc)
* @see org.directwebremoting.Converter#convertOutbound(java.lang.Object, org.directwebremoting.OutboundContext)
*/
public OutboundVariable convertOutbound(Object data, OutboundContext outctx) throws ConversionException
{
// Where we collect out converted children
Map<String, OutboundVariable> ovs = new TreeMap<String, OutboundVariable>();
// We need to do this before collecting the children to save recursion
ObjectOutboundVariable ov = new ObjectOutboundVariable(outctx, data.getClass(), getJavascript());
outctx.put(data, ov);
try
{
Map<String, Property> properties = getPropertyMapFromObject(data, true, false);
for (Entry<String, Property> entry : properties.entrySet())
{
String name = entry.getKey();
Property property = entry.getValue();
Object value = property.getValue(data);
OutboundVariable nested = getConverterManager().convertOutbound(value, outctx);
ovs.put(name, nested);
}
}
catch (ConversionException ex)
{
throw ex;
}
catch (Exception ex)
{
throw new ConversionException(data.getClass(), ex);
}
ov.setChildren(ovs);
return ov;
}
/**
* Set a list of properties excluded from conversion
* @param excludes The space or comma separated list of properties to exclude
*/
public void setExclude(String excludes)
{
if (inclusions != null)
{
throw new IllegalArgumentException("Can't have both inclusions and exclusions for a Converter");
}
exclusions = new ArrayList<String>();
String toSplit = excludes.replace(",", " ");
StringTokenizer st = new StringTokenizer(toSplit);
while (st.hasMoreTokens())
{
String rule = st.nextToken();
if (rule.startsWith("get"))
{
log.warn("Exclusions are based on property names and not method names. '" + rule + "' starts with 'get' so it looks like a method name and not a property name.");
}
exclusions.add(rule);
}
}
/**
* Set a list of properties included from conversion
* @param includes The space or comma separated list of properties to exclude
*/
public void setInclude(String includes)
{
if (exclusions != null)
{
throw new IllegalArgumentException("Can't have both inclusions and exclusions for a Converter");
}
inclusions = new ArrayList<String>();
String toSplit = includes.replace(",", " ");
StringTokenizer st = new StringTokenizer(toSplit);
while (st.hasMoreTokens())
{
String rule = st.nextToken();
if (rule.startsWith("get"))
{
log.warn("Inclusions are based on property names and not method names. '" + rule + "' starts with 'get' so it looks like a method name and not a property name.");
}
inclusions.add(rule);
}
}
/**
* @param name The class name to use as an implementation of the converted bean
* @throws ClassNotFoundException If the given class can not be found
*/
public void setImplementation(String name) throws ClassNotFoundException
{
setInstanceType(LocalUtil.classForName(name));
}
/**
* Check with the access rules to see if we are allowed to convert a property
* @param property The property to test
* @return true if the property may be marshalled
*/
protected boolean isAllowedByIncludeExcludeRules(String property)
{
if (exclusions != null)
{
// Check each exclusions and return false if we get a match
for (String exclusion : exclusions)
{
if (property.equals(exclusion))
{
return false;
}
}
// So we passed all the exclusions. The setters enforce mutual
// exclusion between exclusions and inclusions so we don't need to
// 'return true' here, we can carry on. This has the advantage that
// we can relax the mutual exclusion at some stage.
}
if (inclusions != null)
{
// Check each inclusion and return true if we get a match
for (String inclusion : inclusions)
{
if (property.equals(inclusion))
{
return true;
}
}
// Since we are white-listing with inclusions and there was not
// match, this property is not allowed.
return false;
}
// default to allow if there are no inclusions or exclusions
return true;
}
/**
* Loop over all the inputs and extract a Map of key:value pairs
* @param paramType The type we are converting to
* @param value The input string
* @return A Map of the tokens in the string
* @throws ConversionException If the marshalling fails
*/
protected static Map<String, String> extractInboundTokens(Class<?> paramType, String value) throws ConversionException
{
Map<String, String> tokens = new HashMap<String, String>();
StringTokenizer st = new StringTokenizer(value, ProtocolConstants.INBOUND_MAP_SEPARATOR);
int size = st.countTokens();
for (int i = 0; i < size; i++)
{
String token = st.nextToken();
if (token.trim().length() == 0)
{
continue;
}
int colonpos = token.indexOf(ProtocolConstants.INBOUND_MAP_ENTRY);
if (colonpos == -1)
{
throw new ConversionException(paramType, "Missing " + ProtocolConstants.INBOUND_MAP_ENTRY + " in object description: " + token);
}
String key = token.substring(0, colonpos).trim();
String val = token.substring(colonpos + 1).trim();
tokens.put(key, val);
}
return tokens;
}
/* (non-Javadoc)
* @see org.directwebremoting.extend.Converter#setConverterManager(org.directwebremoting.extend.ConverterManager)
*/
public void setConverterManager(ConverterManager converterManager)
{
this.converterManager = converterManager;
}
/**
* Accessor for the current ConverterManager
* @return the current ConverterManager
*/
public ConverterManager getConverterManager()
{
return converterManager;
}
/**
* To forward marshalling requests
*/
protected ConverterManager converterManager = null;
/* (non-Javadoc)
* @see org.directwebremoting.convert.NamedConverter#getJavascript()
*/
public String getJavascript()
{
return javascript;
}
/* (non-Javadoc)
* @see org.directwebremoting.convert.NamedConverter#setJavascript(java.lang.String)
*/
public void setJavascript(String javascript)
{
this.javascript = javascript;
}
/**
* The javascript class name for the converted objects
*/
protected String javascript = null;
/* (non-Javadoc)
* @see org.directwebremoting.extend.NamedConverter#getJavascriptSuperClass()
*/
public String getJavascriptSuperClass()
{
return javascriptSuperClass;
}
/* (non-Javadoc)
* @see org.directwebremoting.extend.NamedConverter#setJavascriptSuperClass(java.lang.String)
*/
public void setJavascriptSuperClass(String javascriptSuperClass)
{
this.javascriptSuperClass = javascriptSuperClass;
}
/**
* The javascript class name that will appear as superclass
* for the converted objects
*/
protected String javascriptSuperClass = null;
/* (non-Javadoc)
* @see org.directwebremoting.convert.NamedConverter#getInstanceType()
*/
public Class<?> getInstanceType()
{
return instanceType;
}
/* (non-Javadoc)
* @see org.directwebremoting.convert.NamedConverter#setInstanceType(java.lang.Class)
*/
public void setInstanceType(Class<?> instanceType)
{
this.instanceType = instanceType;
}
/**
* A type that allows us to fulfill an interface or subtype requirement
*/
protected Class<?> instanceType = null;
/**
* Set the parameters to be used for constructor injection
* @param paramsString a comma separated list of type/name pairs.
*/
public void setConstructor(String paramsString)
{
this.paramsString = paramsString;
// Convert a paramString into a list of parameters
StringTokenizer st = new StringTokenizer(paramsString, ",");
while (st.hasMoreTokens())
{
String paramString = st.nextToken().trim();
String[] paramParts = paramString.split(" ");
if (paramParts.length != 2)
{
log.error("Parameter list includes parameter '" + paramString + "' that can't be parsed into a [type] and [name]");
throw new IllegalArgumentException("Badly formatted constructor parameter list. See log console for details.");
}
String typeName = paramParts[0];
try
{
Class<?> type = LocalUtil.classForName(typeName);
Pair<Class<?>, String> parameter = new Pair<Class<?>, String>(type, paramParts[1]);
parameters.add(parameter);
}
catch (ClassNotFoundException ex)
{
if (typeName.contains("."))
{
log.error("Parameter list includes unknown type '" + typeName + "'");
throw new IllegalArgumentException("Unknown type in constructor parameter list. See log console for details.");
}
else
{
try
{
Class<?> type = LocalUtil.classForName("java.lang." + typeName);
Pair<Class<?>, String> parameter = new Pair<Class<?>, String>(type, paramParts[1]);
parameters.add(parameter);
}
catch (ClassNotFoundException ex2)
{
log.error("Parameter list includes unknown type '" + typeName + "' (also tried java.lang." + typeName + ")");
throw new IllegalArgumentException("Unknown type in constructor parameter list. See log console for details.");
}
}
}
}
}
/**
* Returns an immutable List of the inclusions.
*
* @return
*/
public List<String> getInclusions() {
return Collections.unmodifiableList(this.inclusions);
}
/**
* Stored temporarily until the {@link #instanceType} is known so we can
* parse for constructor injection
*/
protected String paramsString;
/**
* The constructor to use if we are doing constructor injection
*/
protected Map<Class<?>, Constructor<?>> constructorCache = new HashMap<Class<?>, Constructor<?>>();
/**
* If we are doing constructor injection, this is the type list
*/
protected final List<Pair<Class<?>, String>> parameters = new ArrayList<Pair<Class<?>,String>>();
/**
* The list of excluded properties
*/
protected List<String> exclusions = null;
/**
* The list of included properties
*/
protected List<String> inclusions = null;
/**
* The log stream
*/
private static final Log log = LogFactory.getLog(BasicObjectConverter.class);
}