Coverage Report

Coverage Report - org.jaxen.function.StringLengthFunction

Classes in this File

Line Coverage

Branch Coverage

Complexity

StringLengthFunction

90%

19/21

100%

5/5

4.667

 /*
  * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/function/StringLengthFunction.java,v 1.12 2006/02/05 21:47:41 elharo Exp $
  * $Revision: 1.12 $
  * $Date: 2006/02/05 21:47:41 $
  *
  * ====================================================================
  *
  * Copyright 2000-2002 bob mcwhirter & James Strachan.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  * 
  *   * Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 
  *   * 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.
  * 
  *   * Neither the name of the Jaxen Project nor the names of its
  *     contributors may be used to endorse or promote products derived 
  *     from this software without specific prior written permission.
  * 
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
  * IS" AND ANY EXPRESS 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 COPYRIGHT OWNER
  * OR 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 Jaxen Project and was originally 
  * created by bob mcwhirter <bob@werken.com> and 
  * James Strachan <jstrachan@apache.org>.  For more information on the 
  * Jaxen Project, please see <http://www.jaxen.org/>.
  * 
  * $Id: StringLengthFunction.java,v 1.12 2006/02/05 21:47:41 elharo Exp $
  */
 
 
 package org.jaxen.function;
 
 import java.util.List;
 
 import org.jaxen.Context;
 import org.jaxen.Function;
 import org.jaxen.FunctionCallException;
 import org.jaxen.Navigator;
 
 /**
  * <p><b>4.2</b> <code><i>number</i> string-length(<i>string</i>)</code></p> 
  * 
  * <p>
  * The <b>string-length</b> function returns the number of <strong>Unicode characters</strong>
  * in its argument. This is <strong>not</strong> necessarily 
  * the same as the number <strong>Java chars</strong>
  * in the corresponding Java string. In particular, if the Java <code>String</code>
  * contains surrogate pairs each such pair will be counted as only one character
  * by this function. If the argument is omitted, 
  * it returns the length of the string-value of the context node.
  * </p>
  * 
  * @author bob mcwhirter (bob @ werken.com)
  * @see <a href="http://www.w3.org/TR/xpath#function-string-length" target="_top">Section 
  *      4.2 of the XPath Specification</a>
  */
 public class StringLengthFunction implements Function
 {
 
     
     /**
      * Create a new <code>StringLengthFunction</code> object.
      */
     public StringLengthFunction() {}
     
     
     /**
      * <p>
      * Returns the number of Unicode characters in the string-value of the argument.
      * </p>
      * 
      * @param context the context at the point in the
      *         expression when the function is called
      * @param args a list containing the item whose string-value is to be counted.
      *     If empty, the length of the context node's string-value is returned.
      * 
      * @return a <code>Double</code> giving the number of Unicode characters
      * 
      * @throws FunctionCallException if args has more than one item
      */
     public Object call(Context context,
                        List args) throws FunctionCallException
     {
         if (args.size() == 0)
         {
             return evaluate( context.getNodeSet(),
                              context.getNavigator() );
         } 
         else if (args.size() == 1)
         {
             return evaluate( args.get(0),
                              context.getNavigator() );
         }
 
         throw new FunctionCallException( "string-length() requires one argument." );
     }
 
     /**
      * <p>
      * Returns the number of Unicode characters in the string-value of 
      * an object.
      * </p>
      * 
      * @param obj the object whose string-value is counted
      * @param nav used to calculate the string-values of the first two arguments
      * 
      * @return a <code>Double</code> giving the number of Unicode characters
      * 
      * @throws FunctionCallException if the string contains mismatched surrogates
      */
     public static Double evaluate(Object obj, Navigator nav) throws FunctionCallException
     {
         String str = StringFunction.evaluate( obj, nav );
         // String.length() counts UTF-16 code points; not Unicode characters
         char[] data = str.toCharArray();
         int length = 0;
         for (int i = 0; i < data.length; i++) {
             char c = data[i];
             length++;
             // if this is a high surrogate; assume the next character is
             // is a low surrogate and skip it
             if (c >= 0xD800) {
                 try {
                     char low = data[i+1];
                     if (low < 0xDC00 || low > 0xDFFF) {
                         throw new FunctionCallException("Bad surrogate pair in string " + str);
                     }
                     i++; // increment past low surrogate
                 }
                 catch (ArrayIndexOutOfBoundsException ex) {
                     throw new FunctionCallException("Bad surrogate pair in string " + str);
                 }
             }
         }
         return new Double(length);
     }
     
 }

1		/*
2		* $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/function/StringLengthFunction.java,v 1.12 2006/02/05 21:47:41 elharo Exp $
3		* $Revision: 1.12 $
4		* $Date: 2006/02/05 21:47:41 $
5		*
6		* ====================================================================
7		*
8		* Copyright 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 are
13		* met:
14		*
15		* * Redistributions of source code must retain the above copyright
16		* notice, this list of conditions and the following disclaimer.
17		*
18		* * Redistributions in binary form must reproduce the above copyright
19		* notice, this list of conditions and the following disclaimer in the
20		* documentation and/or other materials provided with the distribution.
21		*
22		* * Neither the name of the Jaxen Project nor the names of its
23		* contributors may be used to endorse or promote products derived
24		* from this software without specific prior written permission.
25		*
26		* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
27		* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28		* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
29		* PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
30		* OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
31		* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
32		* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
33		* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
34		* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
35		* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
36		* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
37		*
38		* ====================================================================
39		* This software consists of voluntary contributions made by many
40		* individuals on behalf of the Jaxen Project and was originally
41		* created by bob mcwhirter <bob@werken.com> and
42		* James Strachan <jstrachan@apache.org>. For more information on the
43		* Jaxen Project, please see <http://www.jaxen.org/>.
44		*
45		* $Id: StringLengthFunction.java,v 1.12 2006/02/05 21:47:41 elharo Exp $
46		*/
47
48
49		package org.jaxen.function;
50
51		import java.util.List;
52
53		import org.jaxen.Context;
54		import org.jaxen.Function;
55		import org.jaxen.FunctionCallException;
56		import org.jaxen.Navigator;
57
58		/**
59		* <p><b>4.2</b> <code><i>number</i> string-length(<i>string</i>)</code></p>
60		*
61		* <p>
62		* The <b>string-length</b> function returns the number of <strong>Unicode characters</strong>
63		* in its argument. This is <strong>not</strong> necessarily
64		* the same as the number <strong>Java chars</strong>
65		* in the corresponding Java string. In particular, if the Java <code>String</code>
66		* contains surrogate pairs each such pair will be counted as only one character
67		* by this function. If the argument is omitted,
68		* it returns the length of the string-value of the context node.
69		* </p>
70		*
71		* @author bob mcwhirter (bob @ werken.com)
72		* @see <a href="http://www.w3.org/TR/xpath#function-string-length" target="_top">Section
73		* 4.2 of the XPath Specification</a>
74		*/
75		public class StringLengthFunction implements Function
76		{
77
78
79		/**
80		* Create a new <code>StringLengthFunction</code> object.
81		*/
82	106	public StringLengthFunction() {}
83
84
85		/**
86		* <p>
87		* Returns the number of Unicode characters in the string-value of the argument.
88		* </p>
89		*
90		* @param context the context at the point in the
91		* expression when the function is called
92		* @param args a list containing the item whose string-value is to be counted.
93		* If empty, the length of the context node's string-value is returned.
94		*
95		* @return a <code>Double</code> giving the number of Unicode characters
96		*
97		* @throws FunctionCallException if args has more than one item
98		*/
99		public Object call(Context context,
100		List args) throws FunctionCallException
101		{
102	14	if (args.size() == 0)
103		{
104	2	return evaluate( context.getNodeSet(),
105		context.getNavigator() );
106		}
107	12	else if (args.size() == 1)
108		{
109	10	return evaluate( args.get(0),
110		context.getNavigator() );
111		}
112
113	2	throw new FunctionCallException( "string-length() requires one argument." );
114		}
115
116		/**
117		* <p>
118		* Returns the number of Unicode characters in the string-value of
119		* an object.
120		* </p>
121		*
122		* @param obj the object whose string-value is counted
123		* @param nav used to calculate the string-values of the first two arguments
124		*
125		* @return a <code>Double</code> giving the number of Unicode characters
126		*
127		* @throws FunctionCallException if the string contains mismatched surrogates
128		*/
129		public static Double evaluate(Object obj, Navigator nav) throws FunctionCallException
130		{
131	112	String str = StringFunction.evaluate( obj, nav );
132		// String.length() counts UTF-16 code points; not Unicode characters
133	112	char[] data = str.toCharArray();
134	112	int length = 0;
135	606	for (int i = 0; i < data.length; i++) {
136	496	char c = data[i];
137	496	length++;
138		// if this is a high surrogate; assume the next character is
139		// is a low surrogate and skip it
140	496	if (c >= 0xD800) {
141		try {
142	10	char low = data[i+1];
143	10	if (low < 0xDC00 \|\| low > 0xDFFF) {
144	2	throw new FunctionCallException("Bad surrogate pair in string " + str);
145		}
146	8	i++; // increment past low surrogate
147		}
148	0	catch (ArrayIndexOutOfBoundsException ex) {
149	0	throw new FunctionCallException("Bad surrogate pair in string " + str);
150	8	}
151		}
152		}
153	110	return new Double(length);
154		}
155
156		}