001: /*
002: * The Apache Software License, Version 1.1
003: *
004: * Copyright (c) 1999 The Apache Software Foundation. All rights
005: * reserved.
006: *
007: * Redistribution and use in source and binary forms, with or without
008: * modification, are permitted provided that the following conditions
009: * are met:
010: *
011: * 1. Redistributions of source code must retain the above copyright
012: * notice, this list of conditions and the following disclaimer.
013: *
014: * 2. Redistributions in binary form must reproduce the above copyright
015: * notice, this list of conditions and the following disclaimer in
016: * the documentation and/or other materials provided with the
017: * distribution.
018: *
019: * 3. The end-user documentation included with the redistribution, if
020: * any, must include the following acknowlegement:
021: * "This product includes software developed by the
022: * Apache Software Foundation (http://www.apache.org/)."
023: * Alternately, this acknowlegement may appear in the software itself,
024: * if and wherever such third-party acknowlegements normally appear.
025: *
026: * 4. The names "The Jakarta Project", "Tomcat", and "Apache Software
027: * Foundation" must not be used to endorse or promote products derived
028: * from this software without prior written permission. For written
029: * permission, please contact apache@apache.org.
030: *
031: * 5. Products derived from this software may not be called "Apache"
032: * nor may "Apache" appear in their names without prior written
033: * permission of the Apache Group.
034: *
035: * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
036: * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
037: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
038: * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
039: * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
040: * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
041: * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
042: * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
043: * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
044: * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
045: * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
046: * SUCH DAMAGE.
047: * ====================================================================
048: *
049: * This software consists of voluntary contributions made by many
050: * individuals on behalf of the Apache Software Foundation. For more
051: * information on the Apache Software Foundation, please see
052: * <http://www.apache.org/>.
053: *
054: */
055:
056: package org.apache.commons.el;
057:
058: import java.util.List;
059: import java.util.Map;
060: import java.util.Iterator;
061: import java.lang.reflect.*;
062: import javax.servlet.jsp.el.ELException;
063: import javax.servlet.jsp.el.VariableResolver;
064: import javax.servlet.jsp.el.FunctionMapper;
065:
066: /**
067: *
068: * <p>Represents a function call.</p>
069: *
070: * @author Shawn Bayern (in the style of Nathan's other classes)
071: **/
072:
073: public class FunctionInvocation extends Expression {
074: //-------------------------------------
075: // Properties
076: //-------------------------------------
077: // property index
078:
079: private String functionName;
080: private List argumentList;
081:
082: public String getFunctionName() {
083: return functionName;
084: }
085:
086: public void setFunctionName(String f) {
087: functionName = f;
088: }
089:
090: public List getArgumentList() {
091: return argumentList;
092: }
093:
094: public void setArgumentList(List l) {
095: argumentList = l;
096: }
097:
098: //-------------------------------------
099: /**
100: * Constructor
101: **/
102: public FunctionInvocation(String functionName, List argumentList) {
103: this .functionName = functionName;
104: this .argumentList = argumentList;
105: }
106:
107: //-------------------------------------
108: // Expression methods
109: //-------------------------------------
110: /**
111: * Returns the expression in the expression language syntax
112: **/
113: public String getExpressionString() {
114: StringBuffer b = new StringBuffer();
115: b.append(functionName);
116: b.append("(");
117: Iterator i = argumentList.iterator();
118: while (i.hasNext()) {
119: b.append(((Expression) i.next()).getExpressionString());
120: if (i.hasNext())
121: b.append(", ");
122: }
123: b.append(")");
124: return b.toString();
125: }
126:
127: //-------------------------------------
128: /**
129: *
130: * Evaluates by looking up the name in the VariableResolver
131: **/
132: public Object evaluate(VariableResolver pResolver,
133: FunctionMapper functions, Logger pLogger)
134: throws ELException {
135:
136: // if the Map is null, then the function is invalid
137: if (functions == null)
138: pLogger.logError(Constants.UNKNOWN_FUNCTION, functionName);
139:
140: // normalize function name
141: String prefix = null;
142: String localName = null;
143: int index = functionName.indexOf(':');
144: if (index == -1) {
145: prefix = "";
146: localName = functionName;
147: } else {
148: prefix = functionName.substring(0, index);
149: localName = functionName.substring(index + 1);
150: }
151:
152: // ensure that the function's name is mapped
153: Method target = (Method) functions.resolveFunction(prefix,
154: localName);
155: if (target == null)
156: pLogger.logError(Constants.UNKNOWN_FUNCTION, functionName);
157:
158: // ensure that the number of arguments matches the number of parameters
159: Class[] params = target.getParameterTypes();
160: if (params.length != argumentList.size())
161: pLogger.logError(
162: Constants.INAPPROPRIATE_FUNCTION_ARG_COUNT,
163: functionName, new Integer(params.length),
164: new Integer(argumentList.size()));
165:
166: // now, walk through each parameter, evaluating and casting its argument
167: Object[] arguments = new Object[argumentList.size()];
168: for (int i = 0; i < params.length; i++) {
169: // evaluate
170: arguments[i] = ((Expression) argumentList.get(i)).evaluate(
171: pResolver, functions, pLogger);
172: // coerce
173: arguments[i] = Coercions.coerce(arguments[i], params[i],
174: pLogger);
175: }
176:
177: // finally, invoke the target method, which we know to be static
178: try {
179: return (target.invoke(null, arguments));
180: } catch (InvocationTargetException ex) {
181: pLogger.logError(Constants.FUNCTION_INVOCATION_ERROR, ex
182: .getTargetException(), functionName);
183: return null;
184: } catch (Exception ex) {
185: pLogger.logError(Constants.FUNCTION_INVOCATION_ERROR, ex,
186: functionName);
187: return null;
188: }
189: }
190:
191: //-------------------------------------
192: }
|