Java tutorial
/* * 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 apache@apache.org. * * 5. Products derived from this software may not be called "Apache" * nor may "Apache" appear in their names without prior written * permission of the Apache Group. * * 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 * <http://www.apache.org/>. * */ package org.apache.commons.el; import java.util.List; import javax.servlet.jsp.el.ELException; import javax.servlet.jsp.el.VariableResolver; import javax.servlet.jsp.el.FunctionMapper; /** * * <p> * Represents a dynamic value, which consists of a prefix and an optional set of ValueSuffix elements. A prefix is something like an identifier, and a * suffix is something like a "property of" or "indexed element of" operator. * * @author Nathan Abramson - Art Technology Group * @author Shawn Bayern * @version $Change: 181177 $$DateTime: 2001/06/26 08:45:09 $$Author: luehe $ **/ public class ComplexValue extends Expression { // ------------------------------------- // Properties // ------------------------------------- // property prefix Expression mPrefix; public Expression getPrefix() { return mPrefix; } public void setPrefix(Expression pPrefix) { mPrefix = pPrefix; } // ------------------------------------- // property suffixes List mSuffixes; public List getSuffixes() { return mSuffixes; } public void setSuffixes(List pSuffixes) { mSuffixes = pSuffixes; } // ------------------------------------- /** * * Constructor **/ public ComplexValue(Expression pPrefix, List pSuffixes) { mPrefix = pPrefix; mSuffixes = pSuffixes; } // ------------------------------------- // Expression methods // ------------------------------------- /** * * Returns the expression in the expression language syntax **/ public String getExpressionString() { StringBuffer buf = new StringBuffer(); buf.append(mPrefix.getExpressionString()); for (int i = 0; mSuffixes != null && i < mSuffixes.size(); i++) { ValueSuffix suffix = (ValueSuffix) mSuffixes.get(i); buf.append(suffix.getExpressionString()); } return buf.toString(); } // ------------------------------------- /** * * Evaluates by evaluating the prefix, then applying the suffixes **/ public Object evaluate(VariableResolver pResolver, FunctionMapper functions, Logger pLogger) throws ELException { Object ret = mPrefix.evaluate(pResolver, functions, pLogger); // Apply the suffixes for (int i = 0; mSuffixes != null && i < mSuffixes.size(); i++) { ValueSuffix suffix = (ValueSuffix) mSuffixes.get(i); ret = suffix.evaluate(ret, pResolver, functions, pLogger); } return ret; } // ------------------------------------- }