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/*
* The Apache Software License, Version 1.1
*
* Copyright (c) 1999 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution, if
* any, must include the following acknowlegement:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowlegement may appear in the software itself,
* if and wherever such third-party acknowlegements normally appear.
*
* 4. The names "The Jakarta Project", "Tomcat", and "Apache Software
* Foundation" must not be used to endorse or promote products derived
* from this software without prior written permission. For written
* permission, please contact [email protected].
*
* 5. Products derived from this software may not be called "Apache"
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*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* Represents a function call.
*
* @author Shawn Bayern (in the style of Nathan's other classes)
**/
public class FunctionInvocation
extends Expression
{
//-------------------------------------
// Properties
//-------------------------------------
// property index
private String functionName;
private List argumentList;
public String getFunctionName() { return functionName; }
public void setFunctionName(String f) { functionName = f; }
public List getArgumentList() { return argumentList; }
public void setArgumentList(List l) { argumentList = l; }
//-------------------------------------
/**
* Constructor
**/
public FunctionInvocation (String functionName, List argumentList)
{
this.functionName = functionName;
this.argumentList = argumentList;
}
//-------------------------------------
// Expression methods
//-------------------------------------
/**
* Returns the expression in the expression language syntax
**/
public String getExpressionString ()
{
StringBuffer b = new StringBuffer();
b.append(functionName);
b.append("(");
Iterator i = argumentList.iterator();
while (i.hasNext()) {
b.append(((Expression) i.next()).getExpressionString());
if (i.hasNext())
b.append(", ");
}
b.append(")");
return b.toString();
}
//-------------------------------------
/**
*
* Evaluates by looking up the name in the VariableResolver
**/
public Object evaluate (VariableResolver pResolver,
FunctionMapper functions,
Logger pLogger)
throws ELException
{
// if the Map is null, then the function is invalid
if (functions == null)
pLogger.logError(Constants.UNKNOWN_FUNCTION, functionName);
// normalize function name
String prefix = null;
String localName = null;
int index = functionName.indexOf( ':' );
if (index == -1) {
prefix = "";
localName = functionName;
} else {
prefix = functionName.substring( 0, index );
localName = functionName.substring( index + 1 );
}
// ensure that the function's name is mapped
Method target = functions.resolveFunction(prefix, localName);
if (target == null)
pLogger.logError(Constants.UNKNOWN_FUNCTION, functionName);
// ensure that the number of arguments matches the number of parameters
Class[] params = target.getParameterTypes();
if (params.length != argumentList.size())
pLogger.logError(Constants.INAPPROPRIATE_FUNCTION_ARG_COUNT,
functionName, new Integer(params.length),
new Integer(argumentList.size()));
// now, walk through each parameter, evaluating and casting its argument
Object[] arguments = new Object[argumentList.size()];
for (int i = 0; i < params.length; i++) {
// evaluate
arguments[i] = ((Expression) argumentList.get(i)).evaluate(pResolver,
functions,
pLogger);
// coerce
arguments[i] = Coercions.coerce(arguments[i], params[i], pLogger);
}
// finally, invoke the target method, which we know to be static
try {
return (target.invoke(null, arguments));
} catch (InvocationTargetException ex) {
pLogger.logError(Constants.FUNCTION_INVOCATION_ERROR,
ex.getTargetException(),
functionName);
return null;
} catch (Exception ex) {
pLogger.logError(Constants.FUNCTION_INVOCATION_ERROR, ex, functionName);
return null;
}
}
//-------------------------------------
}