View Javadoc

    1   /* Generated By:JavaCC: Do not edit this line. ParseException.java Version 3.0 */
    2   package org.apache.commons.jxpath.ri.parser;
    3
    4   /***
    5    * This exception is thrown when parse errors are encountered.
    6    * You can explicitly create objects of this exception type by
    7    * calling the method generateParseException in the generated
    8    * parser.
    9    *
    10   * You can modify this class to customize your error reporting
    11   * mechanisms so long as you retain the public fields.
    12   */
    13  public class ParseException extends Exception {
    14
    15    /***
    16     * This constructor is used by the method "generateParseException"
    17     * in the generated parser.  Calling this constructor generates
    18     * a new object of this type with the fields "currentToken",
    19     * "expectedTokenSequences", and "tokenImage" set.  The boolean
    20     * flag "specialConstructor" is also set to true to indicate that
    21     * this constructor was used to create this object.
    22     * This constructor calls its super class with the empty string
    23     * to force the "toString" method of parent class "Throwable" to
    24     * print the error message in the form:
    25     *     ParseException: <result of getMessage>
    26     */
    27    public ParseException(Token currentTokenVal,
    28                          int[][] expectedTokenSequencesVal,
    29                          String[] tokenImageVal
    30                         )
    31    {
    32      super("");
    33      specialConstructor = true;
    34      currentToken = currentTokenVal;
    35      expectedTokenSequences = expectedTokenSequencesVal;
    36      tokenImage = tokenImageVal;
    37    }
    38
    39    /***
    40     * The following constructors are for use by you for whatever
    41     * purpose you can think of.  Constructing the exception in this
    42     * manner makes the exception behave in the normal way - i.e., as
    43     * documented in the class "Throwable".  The fields "errorToken",
    44     * "expectedTokenSequences", and "tokenImage" do not contain
    45     * relevant information.  The JavaCC generated code does not use
    46     * these constructors.
    47     */
    48
    49    public ParseException() {
    50      super();
    51      specialConstructor = false;
    52    }
    53
    54    public ParseException(String message) {
    55      super(message);
    56      specialConstructor = false;
    57    }
    58
    59    /***
    60     * This variable determines which constructor was used to create
    61     * this object and thereby affects the semantics of the
    62     * "getMessage" method (see below).
    63     */
    64    protected boolean specialConstructor;
    65
    66    /***
    67     * This is the last token that has been consumed successfully.  If
    68     * this object has been created due to a parse error, the token
    69     * followng this token will (therefore) be the first error token.
    70     */
    71    public Token currentToken;
    72
    73    /***
    74     * Each entry in this array is an array of integers.  Each array
    75     * of integers represents a sequence of tokens (by their ordinal
    76     * values) that is expected at this point of the parse.
    77     */
    78    public int[][] expectedTokenSequences;
    79
    80    /***
    81     * This is a reference to the "tokenImage" array of the generated
    82     * parser within which the parse error occurred.  This array is
    83     * defined in the generated ...Constants interface.
    84     */
    85    public String[] tokenImage;
    86
    87    /***
    88     * This method has the standard behavior when this object has been
    89     * created using the standard constructors.  Otherwise, it uses
    90     * "currentToken" and "expectedTokenSequences" to generate a parse
    91     * error message and returns it.  If this object has been created
    92     * due to a parse error, and you do not catch it (it gets thrown
    93     * from the parser), then this method is called during the printing
    94     * of the final stack trace, and hence the correct error message
    95     * gets displayed.
    96     */
    97    public String getMessage() {
    98      if (!specialConstructor) {
    99        return super.getMessage();
    100     }
    101     String expected = "";
    102     int maxSize = 0;
    103     for (int i = 0; i < expectedTokenSequences.length; i++) {
    104       if (maxSize < expectedTokenSequences[i].length) {
    105         maxSize = expectedTokenSequences[i].length;
    106       }
    107       for (int j = 0; j < expectedTokenSequences[i].length; j++) {
    108         expected += tokenImage[expectedTokenSequences[i][j]] + " ";
    109       }
    110       if (expectedTokenSequences[i][expectedTokenSequences[i].length - 1] != 0) {
    111         expected += "...";
    112       }
    113       expected += eol + "    ";
    114     }
    115     String retval = "Encountered \"";
    116     Token tok = currentToken.next;
    117     for (int i = 0; i < maxSize; i++) {
    118       if (i != 0) retval += " ";
    119       if (tok.kind == 0) {
    120         retval += tokenImage[0];
    121         break;
    122       }
    123       retval += add_escapes(tok.image);
    124       tok = tok.next;
    125     }
    126     retval += "\" at line " + currentToken.next.beginLine + ", column " + currentToken.next.beginColumn;
    127     retval += "." + eol;
    128     if (expectedTokenSequences.length == 1) {
    129       retval += "Was expecting:" + eol + "    ";
    130     } else {
    131       retval += "Was expecting one of:" + eol + "    ";
    132     }
    133     retval += expected;
    134     return retval;
    135   }
    136
    137   /***
    138    * The end of line string for this machine.
    139    */
    140   protected String eol = System.getProperty("line.separator", "\n");
    141
    142   /***
    143    * Used to convert raw characters to their escaped version
    144    * when these raw version cannot be used as part of an ASCII
    145    * string literal.
    146    */
    147   protected String add_escapes(String str) {
    148       StringBuffer retval = new StringBuffer();
    149       char ch;
    150       for (int i = 0; i < str.length(); i++) {
    151         switch (str.charAt(i))
    152         {
    153            case 0 :
    154               continue;
    155            case '\b':
    156               retval.append("//b");
    157               continue;
    158            case '\t':
    159               retval.append("//t");
    160               continue;
    161            case '\n':
    162               retval.append("//n");
    163               continue;
    164            case '\f':
    165               retval.append("//f");
    166               continue;
    167            case '\r':
    168               retval.append("//r");
    169               continue;
    170            case '\"':
    171               retval.append("//\"");
    172               continue;
    173            case '\'':
    174               retval.append("//\'");
    175               continue;
    176            case '//':
    177               retval.append("////");
    178               continue;
    179            default:
    180               if ((ch = str.charAt(i)) < 0x20 || ch > 0x7e) {
    181                  String s = "0000" + Integer.toString(ch, 16);
    182                  retval.append("//u" + s.substring(s.length() - 4, s.length()));
    183               } else {
    184                  retval.append(ch);
    185               }
    186               continue;
    187         }
    188       }
    189       return retval.toString();
    190    }
    191
    192 }