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Java > Open Source Codes > org > apache > cayenne > exp > parser > ParseException


1 /* Generated By:JavaCC: Do not edit this line. ParseException.java Version 3.0 */
2 /*****************************************************************
3  * Licensed to the Apache Software Foundation (ASF) under one
4  * or more contributor license agreements. See the NOTICE file
5  * distributed with this work for additional information
6  * regarding copyright ownership. The ASF licenses this file
7  * to you under the Apache License, Version 2.0 (the
8  * "License"); you may not use this file except in compliance
9  * with the License. You may obtain a copy of the License at
10  *
11  * http://www.apache.org/licenses/LICENSE-2.0
12  *
13  * Unless required by applicable law or agreed to in writing,
14  * software distributed under the License is distributed on an
15  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
16  * KIND, either express or implied. See the License for the
17  * specific language governing permissions and limitations
18  * under the License.
19  ****************************************************************/
20
21 package org.apache.cayenne.exp.parser;
22
23 /**
24  * This exception is thrown when parse errors are encountered.
25  * You can explicitly create objects of this exception type by
26  * calling the method generateParseException in the generated
27  * parser.
28  *
29  * You can modify this class to customize your error reporting
30  * mechanisms so long as you retain the public fields.
31  */
32 public class ParseException extends Exception JavaDoc {
33
34   /**
35    * This constructor is used by the method "generateParseException"
36    * in the generated parser. Calling this constructor generates
37    * a new object of this type with the fields "currentToken",
38    * "expectedTokenSequences", and "tokenImage" set. The boolean
39    * flag "specialConstructor" is also set to true to indicate that
40    * this constructor was used to create this object.
41    * This constructor calls its super class with the empty string
42    * to force the "toString" method of parent class "Throwable" to
43    * print the error message in the form:
44    * ParseException: <result of getMessage>
45    */
46   public ParseException(Token currentTokenVal,
47                         int[][] expectedTokenSequencesVal,
48                         String JavaDoc[] tokenImageVal
49                        )
50   {
51     super("");
52     specialConstructor = true;
53     currentToken = currentTokenVal;
54     expectedTokenSequences = expectedTokenSequencesVal;
55     tokenImage = tokenImageVal;
56   }
57
58   /**
59    * The following constructors are for use by you for whatever
60    * purpose you can think of. Constructing the exception in this
61    * manner makes the exception behave in the normal way - i.e., as
62    * documented in the class "Throwable". The fields "errorToken",
63    * "expectedTokenSequences", and "tokenImage" do not contain
64    * relevant information. The JavaCC generated code does not use
65    * these constructors.
66    */
67
68   public ParseException() {
69     super();
70     specialConstructor = false;
71   }
72
73   public ParseException(String JavaDoc message) {
74     super(message);
75     specialConstructor = false;
76   }
77
78   /**
79    * This variable determines which constructor was used to create
80    * this object and thereby affects the semantics of the
81    * "getMessage" method (see below).
82    */
83   protected boolean specialConstructor;
84
85   /**
86    * This is the last token that has been consumed successfully. If
87    * this object has been created due to a parse error, the token
88    * followng this token will (therefore) be the first error token.
89    */
90   public Token currentToken;
91
92   /**
93    * Each entry in this array is an array of integers. Each array
94    * of integers represents a sequence of tokens (by their ordinal
95    * values) that is expected at this point of the parse.
96    */
97   public int[][] expectedTokenSequences;
98
99   /**
100    * This is a reference to the "tokenImage" array of the generated
101    * parser within which the parse error occurred. This array is
102    * defined in the generated ...Constants interface.
103    */
104   public String JavaDoc[] tokenImage;
105
106   /**
107    * This method has the standard behavior when this object has been
108    * created using the standard constructors. Otherwise, it uses
109    * "currentToken" and "expectedTokenSequences" to generate a parse
110    * error message and returns it. If this object has been created
111    * due to a parse error, and you do not catch it (it gets thrown
112    * from the parser), then this method is called during the printing
113    * of the final stack trace, and hence the correct error message
114    * gets displayed.
115    */
116   public String JavaDoc getMessage() {
117     if (!specialConstructor) {
118       return super.getMessage();
119     }
120     String JavaDoc expected = "";
121     int maxSize = 0;
122     for (int i = 0; i < expectedTokenSequences.length; i++) {
123       if (maxSize < expectedTokenSequences[i].length) {
124         maxSize = expectedTokenSequences[i].length;
125       }
126       for (int j = 0; j < expectedTokenSequences[i].length; j++) {
127         expected += tokenImage[expectedTokenSequences[i][j]] + " ";
128       }
129       if (expectedTokenSequences[i][expectedTokenSequences[i].length - 1] != 0) {
130         expected += "...";
131       }
132       expected += eol + " ";
133     }
134     String JavaDoc retval = "Encountered \"";
135     Token tok = currentToken.next;
136     for (int i = 0; i < maxSize; i++) {
137       if (i != 0) retval += " ";
138       if (tok.kind == 0) {
139         retval += tokenImage[0];
140         break;
141       }
142       retval += add_escapes(tok.image);
143       tok = tok.next;
144     }
145     retval += "\" at line " + currentToken.next.beginLine + ", column " + currentToken.next.beginColumn;
146     retval += "." + eol;
147     if (expectedTokenSequences.length == 1) {
148       retval += "Was expecting:" + eol + " ";
149     } else {
150       retval += "Was expecting one of:" + eol + " ";
151     }
152     retval += expected;
153     return retval;
154   }
155
156   /**
157    * The end of line string for this machine.
158    */
159   protected String JavaDoc eol = System.getProperty("line.separator", "\n");
160  
161   /**
162    * Used to convert raw characters to their escaped version
163    * when these raw version cannot be used as part of an ASCII
164    * string literal.
165    */
166   protected String JavaDoc add_escapes(String JavaDoc str) {
167       StringBuffer JavaDoc retval = new StringBuffer JavaDoc();
168       char ch;
169       for (int i = 0; i < str.length(); i++) {
170         switch (str.charAt(i))
171         {
172            case 0 :
173               continue;
174            case '\b':
175               retval.append("\\b");
176               continue;
177            case '\t':
178               retval.append("\\t");
179               continue;
180            case '\n':
181               retval.append("\\n");
182               continue;
183            case '\f':
184               retval.append("\\f");
185               continue;
186            case '\r':
187               retval.append("\\r");
188               continue;
189            case '\"':
190               retval.append("\\\"");
191               continue;
192            case '\'':
193               retval.append("\\\'");
194               continue;
195            case '\\':
196               retval.append("\\\\");
197               continue;
198            default:
199               if ((ch = str.charAt(i)) < 0x20 || ch > 0x7e) {
200                  String JavaDoc s = "0000" + Integer.toString(ch, 16);
201                  retval.append("\\u" + s.substring(s.length() - 4, s.length()));
202               } else {
203                  retval.append(ch);
204               }
205               continue;
206         }
207       }
208       return retval.toString();
209    }
210
211 }
212
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