org.directwebremoting.extend.Call Maven / Gradle / Ivy
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/*
* 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.extend;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.directwebremoting.util.LocalUtil;
/**
* Call is a POJO to encapsulate the information required to make a single java
* call, including the result of the call (either returned data or exception).
* Either the Method and Parameters should be filled in to allow a call to be
* made or, the exception should be filled in indicating that things have gone
* wrong already.
* @author Joe Walker [joe at getahead dot ltd dot uk]
*/
public class Call
{
public Call(String callId, String scriptName, String methodName)
{
this.callId = callId;
this.scriptName = scriptName;
this.methodName = methodName;
}
public void setMarshallFailure(Throwable exception)
{
this.exception = exception;
this.methodDeclaration = null;
this.parameters = null;
}
/**
* @return the exception
*/
public Throwable getException()
{
return exception;
}
/**
* @return the method
*/
public MethodDeclaration getMethodDeclaration()
{
return methodDeclaration;
}
/**
* @param methodDeclaration the method to set
*/
public void setMethodDeclaration(MethodDeclaration methodDeclaration)
{
this.methodDeclaration = methodDeclaration;
}
/**
* @return the parameters
*/
public Object[] getParameters()
{
return parameters;
}
/**
* @param parameters the parameters to set
*/
public void setParameters(Object[] parameters)
{
this.parameters = parameters;
}
/**
* @return Returns the callId.
*/
public String getCallId()
{
return callId;
}
/**
* @return Returns the scriptName.
*/
public String getScriptName()
{
return scriptName;
}
/**
* @return Returns the methodName.
*/
public String getMethodName()
{
return methodName;
}
/**
* Find the method the best matches the method name and parameters.
*
* This method used to be significantly more detailed in its matching
* sequences, this simpler version is less defined in the order in which it
* matches methods, but able to find more matches. If we discover that this
* version creates problems, the old version was around up to revision 2317.
*/
public void findMethod(ModuleManager moduleManager, ConverterManager converterManager, InboundContext inctx, int callNum)
{
if (scriptName == null)
{
throw new IllegalArgumentException("Missing class parameter");
}
if (methodName == null)
{
throw new IllegalArgumentException("Missing method parameter");
}
int inputArgCount = inctx.getParameterCount(callNum);
// Get a mutable list of all methods on the type specified by the creator
Module module = moduleManager.getModule(scriptName, true);
List allMethods = new ArrayList();
allMethods.addAll(Arrays.asList(module.getMethods()));
// Remove all methods that don't have a matching name
for (Iterator it = allMethods.iterator(); it.hasNext();)
{
if (!it.next().getName().equals(methodName))
{
it.remove();
}
}
if (allMethods.isEmpty())
{
// Not even a name match
log.warn("No method called '" + methodName + "' found in " + module.toString());
throw new IllegalArgumentException("Method name not found. See logs for details");
}
// Remove all the methods where we can't convert the parameters
allMethodsLoop:
for (Iterator it = allMethods.iterator(); it.hasNext();)
{
MethodDeclaration m = it.next();
Class[] methodParamTypes = m.getParameterTypes();
// Remove non-varargs methods which declare less params than were passed
if (!m.isVarArgs() && methodParamTypes.length < inputArgCount)
{
it.remove();
continue allMethodsLoop;
}
// Remove methods where we can't convert the input
int argIndex = 0;
for (int paramIndex = 0; paramIndex < methodParamTypes.length; paramIndex++)
{
Class methodParamType = methodParamTypes[paramIndex];
if (LocalUtil.isServletClass(methodParamType))
{
continue;
}
InboundVariable param = inctx.getParameter(callNum, argIndex);
Class inputType = converterManager.getClientDeclaredType(param);
// If we can't convert this parameter type, ignore the method
if (inputType == null && !converterManager.isConvertable(methodParamType))
{
it.remove();
continue allMethodsLoop;
}
// Remove methods which declare more non-nullable parameters than were passed
if (inputArgCount <= argIndex && methodParamType.isPrimitive())
{
it.remove();
continue allMethodsLoop;
}
// Remove methods where the client passed a type and we can't use it.
if (inputType != null && !methodParamType.isAssignableFrom(inputType))
{
it.remove();
continue allMethodsLoop;
}
argIndex++;
}
}
// Added to increase our ability to call overloaded methods accurately!
// Is the inbound JavaScript type assignable to methodParamType?
// We are limited to what JavaScript gives us (number, date, boolean, etc.)
// We only want to performn this if there are multiple methods with the same name (hack for now).
if (allMethods.size() > 1) {
allMethodsLoop2:
for (Iterator it = allMethods.iterator(); it.hasNext();)
{
MethodDeclaration m = it.next();
Class[] methodParamTypes = m.getParameterTypes();
// Remove methods where we can't convert the input
for (int i = 0; i < methodParamTypes.length; i++)
{
Class methodParamType = methodParamTypes[i];
InboundVariable param = inctx.getParameter(callNum, i);
String javaScriptType = param.getType();
// If this method takes a vararg, the JavaScript type being passed is not
// an array, and this is the var argument we need to use the component type of the argument.
// Otherwise this method will be removed because javaScriptType (not array) and methodParamType
// (Array - this is the vararg) won't match.
if (m.isVarArgs() && !"array".equals(javaScriptType) && i == methodParamTypes.length - 1)
{
methodParamType=methodParamType.getComponentType();
}
if (!LocalUtil.isJavaScriptTypeAssignableTo(javaScriptType, methodParamType))
{
it.remove();
continue allMethodsLoop2;
}
}
}
}
if (allMethods.isEmpty())
{
// Not even a name match
log.warn("No methods called '" + methodName + "' in " + module.toString() + " are applicable for the passed parameters.");
throw new IllegalArgumentException("Method not found. See logs for details");
}
else if (allMethods.size() == 1)
{
methodDeclaration = allMethods.get(0);
return;
}
// If we have methods that exactly match the param count we use a
// different matching algorithm, to when we don't
List exactParamCountMatches = new ArrayList();
for (MethodDeclaration m : allMethods)
{
if (!m.isVarArgs() && m.getParameterTypes().length == inputArgCount)
{
exactParamCountMatches.add(m);
}
}
if (exactParamCountMatches.size() == 1)
{
// One method with the right number of params - use that
methodDeclaration = exactParamCountMatches.get(0);
return;
}
else if (exactParamCountMatches.size() == 2)
{
// Two methods with same name, the correct number of parameters and convertible inputs.
// Hope it's due to generics (DWR-343). Still check
int choose = -1;
boolean compatible = true;
Class[] params1 = exactParamCountMatches.get(0).getParameterTypes();
Class[] params2 = exactParamCountMatches.get(1).getParameterTypes();
for (int i = 0; i < params1.length; i++)
{
if (compatible && !params1[i].equals(params2[i]))
{
if (choose < 0)
{
choose = params1[i].isAssignableFrom(params2[i]) ? 1 : 0;
}
compatible &= ((choose == 1) || params2[i].isAssignableFrom(params1[i]));
}
}
if (compatible && (choose >= 0))
{
methodDeclaration = exactParamCountMatches.get(choose); // Select the most concrete of the two
return;
}
}
// Lots of methods with the right name, but none with the right
// parameter count. If we have exactly one varargs method, then we
// try that, otherwise we bail.
List varargsMethods = new ArrayList();
for (MethodDeclaration m : allMethods)
{
if (m.isVarArgs())
{
varargsMethods.add(m);
}
}
if (varargsMethods.size() == 1)
{
methodDeclaration = varargsMethods.get(0);
return;
}
log.warn("Can't find single method to match method '" + methodName + "' in " + module.toString());
log.warn("- DWR does not continue where there is ambiguity about which method to execute.");
log.warn("- Input parameters: " + inputArgCount + ".Matching methods with param count match: " + exactParamCountMatches.size() + ". Number of matching varargs methods: " + varargsMethods.size());
log.warn("- Potential matches include:");
for (MethodDeclaration m : allMethods)
{
log.warn(" - " + m.toString());
}
throw new IllegalArgumentException("Method not found. See logs for details");
}
/* (non-Javadoc)
* @see java.lang.Object#toString()
*/
@Override
public String toString()
{
try
{
return scriptName + "." + methodName + "(...)";
}
catch (Exception ex)
{
return "Call(undefined)";
}
}
private final String callId;
private final String scriptName;
private final String methodName;
private MethodDeclaration methodDeclaration = null;
private Object[] parameters = null;
private Throwable exception = null;
/**
* The log stream
*/
private static final Log log = LogFactory.getLog(Call.class);
}