Source code: org/apache/commons/el/ExpressionString.java
1 /*
2 * The Apache Software License, Version 1.1
3 *
4 * Copyright (c) 1999 The Apache Software Foundation. All rights
5 * reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 *
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in
16 * the documentation and/or other materials provided with the
17 * distribution.
18 *
19 * 3. The end-user documentation included with the redistribution, if
20 * any, must include the following acknowlegement:
21 * "This product includes software developed by the
22 * Apache Software Foundation (http://www.apache.org/)."
23 * Alternately, this acknowlegement may appear in the software itself,
24 * if and wherever such third-party acknowlegements normally appear.
25 *
26 * 4. The names "The Jakarta Project", "Tomcat", and "Apache Software
27 * Foundation" must not be used to endorse or promote products derived
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31 * 5. Products derived from this software may not be called "Apache"
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34 *
35 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
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37 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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47 * ====================================================================
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49 * This software consists of voluntary contributions made by many
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55
56 package org.apache.commons.el;
57
58 import javax.servlet.jsp.el.ELException;
59 import javax.servlet.jsp.el.VariableResolver;
60 import javax.servlet.jsp.el.FunctionMapper;
61
62 /**
63 *
64 * <p>Represents an expression String consisting of a mixture of
65 * Strings and Expressions.
66 *
67 * @author Nathan Abramson - Art Technology Group
68 * @author Shawn Bayern
69 * @version $Change: 181177 $$DateTime: 2001/06/26 08:45:09 $$Author: luehe $
70 **/
71
72 public class ExpressionString
73 {
74 //-------------------------------------
75 // Properties
76 //-------------------------------------
77 // property elements
78
79 Object [] mElements;
80 public Object [] getElements ()
81 { return mElements; }
82 public void setElements (Object [] pElements)
83 { mElements = pElements; }
84
85 //-------------------------------------
86 /**
87 *
88 * Constructor
89 **/
90 public ExpressionString (Object [] pElements)
91 {
92 mElements = pElements;
93 }
94
95 //-------------------------------------
96 /**
97 *
98 * Evaluates the expression string by evaluating each element,
99 * converting it to a String (using toString, or "" for null values)
100 * and concatenating the results into a single String.
101 **/
102 public String evaluate (VariableResolver pResolver,
103 FunctionMapper functions,
104 Logger pLogger)
105 throws ELException
106 {
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 }
113 else if (elem instanceof Expression) {
114 Object val =
115 ((Expression) elem).evaluate (pResolver,
116 functions,
117 pLogger);
118 if (val != null) {
119 buf.append (val.toString ());
120 }
121 }
122 }
123 return buf.toString ();
124 }
125
126 //-------------------------------------
127 /**
128 *
129 * Returns the expression in the expression language syntax
130 **/
131 public String getExpressionString ()
132 {
133 StringBuffer buf = new StringBuffer ();
134 for (int i = 0; i < mElements.length; i++) {
135 Object elem = mElements [i];
136 if (elem instanceof String) {
137 buf.append ((String) elem);
138 }
139 else if (elem instanceof Expression) {
140 buf.append ("${");
141 buf.append (((Expression) elem).getExpressionString ());
142 buf.append ("}");
143 }
144 }
145 return buf.toString ();
146 }
147
148 //-------------------------------------
149 }