KickJava   Java API By Example, From Geeks To Geeks.

Java > Open Source Codes > org > jaxen > function > ConcatFunction


1 /*
2  * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/function/ConcatFunction.java,v 1.7 2005/06/26 16:07:23 elharo Exp $
3  * $Revision: 1.7 $
4  * $Date: 2005/06/26 16:07:23 $
5  *
6  * ====================================================================
7  *
8  * Copyright (C) 2000-2002 bob mcwhirter & James Strachan.
9  * All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  *
15  * 1. Redistributions of source code must retain the above copyright
16  * notice, this list of conditions, and the following disclaimer.
17  *
18  * 2. Redistributions in binary form must reproduce the above copyright
19  * notice, this list of conditions, and the disclaimer that follows
20  * these conditions in the documentation and/or other materials
21  * provided with the distribution.
22  *
23  * 3. The name "Jaxen" must not be used to endorse or promote products
24  * derived from this software without prior written permission. For
25  * written permission, please contact license@jaxen.org.
26  *
27  * 4. Products derived from this software may not be called "Jaxen", nor
28  * may "Jaxen" appear in their name, without prior written permission
29  * from the Jaxen Project Management (pm@jaxen.org).
30  *
31  * In addition, we request (but do not require) that you include in the
32  * end-user documentation provided with the redistribution and/or in the
33  * software itself an acknowledgement equivalent to the following:
34  * "This product includes software developed by the
35  * Jaxen Project (http://www.jaxen.org/)."
36  * Alternatively, the acknowledgment may be graphical using the logos
37  * available at http://www.jaxen.org/
38  *
39  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
40  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
41  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
42  * DISCLAIMED. IN NO EVENT SHALL THE Jaxen AUTHORS OR THE PROJECT
43  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
44  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
45  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
46  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
47  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
48  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
49  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50  * SUCH DAMAGE.
51  *
52  * ====================================================================
53  * This software consists of voluntary contributions made by many
54  * individuals on behalf of the Jaxen Project and was originally
55  * created by bob mcwhirter <bob@werken.com> and
56  * James Strachan <jstrachan@apache.org>. For more information on the
57  * Jaxen Project, please see <http://www.jaxen.org/>.
58  *
59  * $Id: ConcatFunction.java,v 1.7 2005/06/26 16:07:23 elharo Exp $
60  */
61
62
63 package org.jaxen.function;
64
65 import java.util.Iterator JavaDoc;
66 import java.util.List JavaDoc;
67
68 import org.jaxen.Context;
69 import org.jaxen.Function;
70 import org.jaxen.FunctionCallException;
71 import org.jaxen.Navigator;
72
73 /**
74  * <b>4.2</b> <code><i>string</i> concat(<i>string</i>,<i>string</i>,<i>string*</i>)</code>
75  * <p>
76  * Concatenates its arguments and returns the resulting string.
77  * </p>
78  *
79  * @author bob mcwhirter (bob@werken.com)
80  *
81  * @see <a HREF="http://www.w3.org/TR/xpath#function-concat">Section 4.2 of the XPath Specification</a>
82  */
83 public class ConcatFunction implements Function
84 {
85
86     /**
87      * Create a new <code>ConcatFunction</code> object.
88      */
89     public ConcatFunction() {}
90     
91     /**
92      * Concatenates the arguments and returns the resulting string.
93      * Non-string items are first converted to strings as if by the
94      * XPath <code>string()<code> function.
95      *
96      * @param context the context at the point in the
97      * expression when the function is called
98      * @param args the list of strings to be concatenated
99      *
100      * @return a <code>String</code> containing the concatenation of the items
101      * of <code>args</code>
102      *
103      * @throws FunctionCallException if <code>args</code> has less than two items
104      */
105     public Object JavaDoc call(Context context,
106                        List JavaDoc args) throws FunctionCallException
107     {
108         if ( args.size() >= 2 )
109         {
110             return evaluate( args,
111                              context.getNavigator() );
112         }
113
114         throw new FunctionCallException("concat() requires at least two arguments");
115     }
116
117     /**
118      * Converts each item in the list to a string and returns the
119      * concatenation of these strings.
120      * If necessary, each item is first converted to a <code>String</code>
121      * as if by the XPath <code>string()</code> function.
122      *
123      * @param list the items to be concatenated
124      * @param nav ignored
125      *
126      * @return the concatenation of the arguments
127      */
128    public static String JavaDoc evaluate(List JavaDoc list,
129                                   Navigator nav)
130     {
131         StringBuffer JavaDoc result = new StringBuffer JavaDoc();
132         Iterator JavaDoc argIter = list.iterator();
133         while ( argIter.hasNext() )
134         {
135             result.append( StringFunction.evaluate( argIter.next(),
136                                                     nav ) );
137         }
138     
139         return result.toString();
140     }
141 }
142
Popular Tags