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.jbpm.jpdl.el.impl;
057:
058: import org.jbpm.jpdl.el.ELException;
059: import org.jbpm.jpdl.el.FunctionMapper;
060: import org.jbpm.jpdl.el.VariableResolver;
061:
062: /**
063: *
064: * <p>Represents an expression String consisting of a mixture of
065: * Strings and Expressions.
066: *
067: * @author Nathan Abramson - Art Technology Group
068: * @author Shawn Bayern
069: * @version $Change: 181177 $$DateTime: 2001/06/26 08:45:09 $$Author$
070: **/
071:
072: public class ExpressionString {
073: //-------------------------------------
074: // Properties
075: //-------------------------------------
076: // property elements
077:
078: Object[] mElements;
079:
080: public Object[] getElements() {
081: return mElements;
082: }
083:
084: public void setElements(Object[] pElements) {
085: mElements = pElements;
086: }
087:
088: //-------------------------------------
089: /**
090: *
091: * Constructor
092: **/
093: public ExpressionString(Object[] pElements) {
094: mElements = pElements;
095: }
096:
097: //-------------------------------------
098: /**
099: *
100: * Evaluates the expression string by evaluating each element,
101: * converting it to a String (using toString, or "" for null values)
102: * and concatenating the results into a single String.
103: **/
104: public String evaluate(VariableResolver pResolver,
105: FunctionMapper functions, Logger pLogger)
106: throws ELException {
107: StringBuffer buf = new StringBuffer();
108: for (int i = 0; i < mElements.length; i++) {
109: Object elem = mElements[i];
110: if (elem instanceof String) {
111: buf.append((String) elem);
112: } else if (elem instanceof Expression) {
113: Object val = ((Expression) elem).evaluate(pResolver,
114: functions, pLogger);
115: if (val != null) {
116: buf.append(val.toString());
117: }
118: }
119: }
120: return buf.toString();
121: }
122:
123: //-------------------------------------
124: /**
125: *
126: * Returns the expression in the expression language syntax
127: **/
128: public String getExpressionString() {
129: StringBuffer buf = new StringBuffer();
130: for (int i = 0; i < mElements.length; i++) {
131: Object elem = mElements[i];
132: if (elem instanceof String) {
133: buf.append((String) elem);
134: } else if (elem instanceof Expression) {
135: buf.append("${");
136: buf.append(((Expression) elem).getExpressionString());
137: buf.append("}");
138: }
139: }
140: return buf.toString();
141: }
142:
143: //-------------------------------------
144: }
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