/* * 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. 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For more * information on the Apache Software Foundation, please see * <http://www.apache.org/>. * */ package org.jbpm.jpdl.el.impl; import java.lang.reflect.InvocationTargetException; import java.lang.reflect.Method; import java.util.Iterator; import java.util.List; import org.jbpm.jpdl.el.ELException; import org.jbpm.jpdl.el.FunctionMapper; import org.jbpm.jpdl.el.VariableResolver; /** * * <p>Represents a function call.</p> * * @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; } } //------------------------------------- }