1
2 /***
3 * JSP Parser for PMD.
4 * @author Pieter � Application Engineers NV/SA � http://www.ae.be
5 */
6
7 package net.sourceforge.pmd.jsp.ast;
8
9 /***
10 * This exception is thrown when parse errors are encountered.
11 * You can explicitly create objects of this exception type by
12 * calling the method generateParseException in the generated
13 * parser.
14 * <p/>
15 * You can modify this class to customize your error reporting
16 * mechanisms so long as you retain the public fields.
17 */
18 public class ParseException extends net.sourceforge.pmd.ast.ParseException {
19
20 /***
21 * This constructor is used by the method "generateParseException"
22 * in the generated parser. Calling this constructor generates
23 * a new object of this type with the fields "currentToken",
24 * "expectedTokenSequences", and "tokenImage" set. The boolean
25 * flag "specialConstructor" is also set to true to indicate that
26 * this constructor was used to create this object.
27 * This constructor calls its super class with the empty string
28 * to force the "toString" method of parent class "Throwable" to
29 * print the error message in the form:
30 * ParseException: <result of getMessage>
31 */
32 public ParseException(Token currentTokenVal,
33 int[][] expectedTokenSequencesVal,
34 String[] tokenImageVal) {
35 super("");
36 specialConstructor = true;
37 currentToken = currentTokenVal;
38 expectedTokenSequences = expectedTokenSequencesVal;
39 tokenImage = tokenImageVal;
40 }
41
42 /***
43 * The following constructors are for use by you for whatever
44 * purpose you can think of. Constructing the exception in this
45 * manner makes the exception behave in the normal way - i.e., as
46 * documented in the class "Throwable". The fields "errorToken",
47 * "expectedTokenSequences", and "tokenImage" do not contain
48 * relevant information. The JavaCC generated code does not use
49 * these constructors.
50 */
51
52 public ParseException() {
53 super();
54 specialConstructor = false;
55 }
56
57 public ParseException(String message) {
58 super(message);
59 specialConstructor = false;
60 }
61
62 /***
63 * This variable determines which constructor was used to create
64 * this object and thereby affects the semantics of the
65 * "getMessage" method (see below).
66 */
67 protected boolean specialConstructor;
68
69 /***
70 * This is the last token that has been consumed successfully. If
71 * this object has been created due to a parse error, the token
72 * followng this token will (therefore) be the first error token.
73 */
74 public Token currentToken;
75
76 /***
77 * Each entry in this array is an array of integers. Each array
78 * of integers represents a sequence of tokens (by their ordinal
79 * values) that is expected at this point of the parse.
80 */
81 public int[][] expectedTokenSequences;
82
83 /***
84 * This is a reference to the "tokenImage" array of the generated
85 * parser within which the parse error occurred. This array is
86 * defined in the generated ...Constants interface.
87 */
88 public String[] tokenImage;
89
90 /***
91 * This method has the standard behavior when this object has been
92 * created using the standard constructors. Otherwise, it uses
93 * "currentToken" and "expectedTokenSequences" to generate a parse
94 * error message and returns it. If this object has been created
95 * due to a parse error, and you do not catch it (it gets thrown
96 * from the parser), then this method is called during the printing
97 * of the final stack trace, and hence the correct error message
98 * gets displayed.
99 */
100 public String getMessage() {
101 if (!specialConstructor) {
102 return super.getMessage();
103 }
104 String expected = "";
105 int maxSize = 0;
106 for (int i = 0; i < expectedTokenSequences.length; i++) {
107 if (maxSize < expectedTokenSequences[i].length) {
108 maxSize = expectedTokenSequences[i].length;
109 }
110 for (int j = 0; j < expectedTokenSequences[i].length; j++) {
111 expected += tokenImage[expectedTokenSequences[i][j]] + " ";
112 }
113 if (expectedTokenSequences[i][expectedTokenSequences[i].length - 1] != 0) {
114 expected += "...";
115 }
116 expected += eol + " ";
117 }
118 String retval = "Encountered \"";
119 Token tok = currentToken.next;
120 for (int i = 0; i < maxSize; i++) {
121 if (i != 0) retval += " ";
122 if (tok.kind == 0) {
123 retval += tokenImage[0];
124 break;
125 }
126 retval += add_escapes(tok.image);
127 tok = tok.next;
128 }
129 retval += "\" at line " + currentToken.next.beginLine + ", column " + currentToken.next.beginColumn;
130 retval += "." + eol;
131 if (expectedTokenSequences.length == 1) {
132 retval += "Was expecting:" + eol + " ";
133 } else {
134 retval += "Was expecting one of:" + eol + " ";
135 }
136 retval += expected;
137 return retval;
138 }
139
140 /***
141 * The end of line string for this machine.
142 */
143 protected String eol = System.getProperty("line.separator", "\n");
144
145 /***
146 * Used to convert raw characters to their escaped version
147 * when these raw version cannot be used as part of an ASCII
148 * string literal.
149 */
150 protected String add_escapes(String str) {
151 StringBuffer retval = new StringBuffer();
152 char ch;
153 for (int i = 0; i < str.length(); i++) {
154 switch (str.charAt(i)) {
155 case 0:
156 continue;
157 case '\b':
158 retval.append("//b");
159 continue;
160 case '\t':
161 retval.append("//t");
162 continue;
163 case '\n':
164 retval.append("//n");
165 continue;
166 case '\f':
167 retval.append("//f");
168 continue;
169 case '\r':
170 retval.append("//r");
171 continue;
172 case '\"':
173 retval.append("//\"");
174 continue;
175 case '\'':
176 retval.append("//\'");
177 continue;
178 case '//':
179 retval.append("////");
180 continue;
181 default:
182 if ((ch = str.charAt(i)) < 0x20 || ch > 0x7e) {
183 String s = "0000" + Integer.toString(ch, 16);
184 retval.append("//u" + s.substring(s.length() - 4, s.length()));
185 } else {
186 retval.append(ch);
187 }
188 continue;
189 }
190 }
191 return retval.toString();
192 }
193
194 }