001: /* Generated By:JavaCC: Do not edit this line. ParseException.java Version 3.0 */
002: package org.apache.velocity.runtime.parser;
003:
004: /**
005: * This exception is thrown when parse errors are encountered.
006: * It is intended to be caught and typically will be rethrown
007: * as a ParseErrorException.
008: *
009: * <p>You can explicitly create objects of this exception type by
010: * calling the method generateParseException in the generated
011: * parser.
012: *
013: * You can modify this class to customize your error reporting
014: * mechanisms so long as you retain the public fields.
015: */
016: public class ParseException extends Exception {
017:
018: private static final long serialVersionUID = -309603325673449381L;
019:
020: /**
021: * This constructor is used by the method "generateParseException"
022: * in the generated parser. Calling this constructor generates
023: * a new object of this type with the fields "currentToken",
024: * "expectedTokenSequences", and "tokenImage" set. The boolean
025: * flag "specialConstructor" is also set to true to indicate that
026: * this constructor was used to create this object.
027: * This constructor calls its super class with the empty string
028: * to force the "toString" method of parent class "Throwable" to
029: * print the error message in the form:
030: * ParseException: <result of getMessage>
031: */
032: public ParseException(Token currentTokenVal,
033: int[][] expectedTokenSequencesVal, String[] tokenImageVal) {
034: super ("");
035: specialConstructor = true;
036: currentToken = currentTokenVal;
037: expectedTokenSequences = expectedTokenSequencesVal;
038: tokenImage = tokenImageVal;
039: }
040:
041: /**
042: * The following constructors are for use by you for whatever
043: * purpose you can think of. Constructing the exception in this
044: * manner makes the exception behave in the normal way - i.e., as
045: * documented in the class "Throwable". The fields "errorToken",
046: * "expectedTokenSequences", and "tokenImage" do not contain
047: * relevant information. The JavaCC generated code does not use
048: * these constructors.
049: */
050:
051: public ParseException() {
052: super ();
053: specialConstructor = false;
054: }
055:
056: public ParseException(String message) {
057: super (message);
058: specialConstructor = false;
059: }
060:
061: /**
062: * This variable determines which constructor was used to create
063: * this object and thereby affects the semantics of the
064: * "getMessage" method (see below).
065: */
066: protected boolean specialConstructor;
067:
068: /**
069: * This is the last token that has been consumed successfully. If
070: * this object has been created due to a parse error, the token
071: * followng this token will (therefore) be the first error token.
072: */
073: public Token currentToken;
074:
075: /**
076: * Each entry in this array is an array of integers. Each array
077: * of integers represents a sequence of tokens (by their ordinal
078: * values) that is expected at this point of the parse.
079: */
080: public int[][] expectedTokenSequences;
081:
082: /**
083: * This is a reference to the "tokenImage" array of the generated
084: * parser within which the parse error occurred. This array is
085: * defined in the generated ...Constants interface.
086: */
087: public String[] tokenImage;
088:
089: /**
090: * This method has the standard behavior when this object has been
091: * created using the standard constructors. Otherwise, it uses
092: * "currentToken" and "expectedTokenSequences" to generate a parse
093: * error message and returns it. If this object has been created
094: * due to a parse error, and you do not catch it (it gets thrown
095: * from the parser), then this method is called during the printing
096: * of the final stack trace, and hence the correct error message
097: * gets displayed.
098: */
099: public String getMessage() {
100: if (!specialConstructor) {
101: return super .getMessage();
102: }
103: String expected = "";
104: int maxSize = 0;
105: for (int i = 0; i < expectedTokenSequences.length; i++) {
106: if (maxSize < expectedTokenSequences[i].length) {
107: maxSize = expectedTokenSequences[i].length;
108: }
109: for (int j = 0; j < expectedTokenSequences[i].length; j++) {
110: expected += tokenImage[expectedTokenSequences[i][j]]
111: + " ";
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)
122: retval += " ";
123: if (tok.kind == 0) {
124: retval += tokenImage[0];
125: break;
126: }
127: retval += add_escapes(tok.image);
128: tok = tok.next;
129: }
130: retval += "\" at line " + currentToken.next.beginLine
131: + ", column " + currentToken.next.beginColumn;
132: retval += "." + eol;
133: if (expectedTokenSequences.length == 1) {
134: retval += "Was expecting:" + eol + " ";
135: } else {
136: retval += "Was expecting one of:" + eol + " ";
137: }
138: retval += expected;
139: return retval;
140: }
141:
142: /**
143: * The end of line string for this machine.
144: */
145: protected String eol = System.getProperty("line.separator", "\n");
146:
147: /**
148: * Used to convert raw characters to their escaped version
149: * when these raw version cannot be used as part of an ASCII
150: * string literal.
151: */
152: protected String add_escapes(String str) {
153: StringBuffer retval = new StringBuffer();
154: char ch;
155: for (int i = 0; i < str.length(); i++) {
156: switch (str.charAt(i)) {
157: case 0:
158: continue;
159: case '\b':
160: retval.append("\\b");
161: continue;
162: case '\t':
163: retval.append("\\t");
164: continue;
165: case '\n':
166: retval.append("\\n");
167: continue;
168: case '\f':
169: retval.append("\\f");
170: continue;
171: case '\r':
172: retval.append("\\r");
173: continue;
174: case '\"':
175: retval.append("\\\"");
176: continue;
177: case '\'':
178: retval.append("\\\'");
179: continue;
180: case '\\':
181: retval.append("\\\\");
182: continue;
183: default:
184: if ((ch = str.charAt(i)) < 0x20 || ch > 0x7e) {
185: String s = "0000" + Integer.toString(ch, 16);
186: retval.append("\\u"
187: + s.substring(s.length() - 4, s.length()));
188: } else {
189: retval.append(ch);
190: }
191: continue;
192: }
193: }
194: return retval.toString();
195: }
196:
197: }
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