001: /*
002: * Portions Copyright 2000-2007 Sun Microsystems, Inc. All Rights
003: * Reserved. Use is subject to license terms.
004: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER
005: *
006: * This program is free software; you can redistribute it and/or
007: * modify it under the terms of the GNU General Public License version
008: * 2 only, as published by the Free Software Foundation.
009: *
010: * This program is distributed in the hope that it will be useful, but
011: * WITHOUT ANY WARRANTY; without even the implied warranty of
012: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
013: * General Public License version 2 for more details (a copy is
014: * included at /legal/license.txt).
015: *
016: * You should have received a copy of the GNU General Public License
017: * version 2 along with this work; if not, write to the Free Software
018: * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
019: * 02110-1301 USA
020: *
021: * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
022: * Clara, CA 95054 or visit www.sun.com if you need additional
023: * information or have any questions.
024: */
025: package gov.nist.core;
026:
027: import com.sun.midp.log.Logging;
028: import com.sun.midp.log.LogChannels;
029:
030: /**
031: * Generic parser class.
032: * All parsers inherit this class.
033: *
034: * @version JAIN-SIP-1.1
035: *
036: *
037: * <a href="{@docRoot}/uncopyright.html">This code is in the public domain.</a>
038: *
039: */
040: public abstract class ParserCore {
041: /** Flag to indicate parsing diagnostics should be logged. */
042: public static final boolean debug = false;
043: /* (Logging.REPORT_LEVEL <= Logging.INFORMATION); */
044:
045: /** Current nesting level int recursive parsing. */
046: protected static int nesting_level;
047: /** Current lexer engine. */
048: protected LexerCore lexer;
049:
050: /**
051: * Gets a name value pair with the specified separator.
052: * @param separator character to use int encoded return value
053: * @return encoded name value text string.
054: * @exception ParseException if a parsing error occurs
055: */
056: protected NameValue nameValue(char separator) throws ParseException {
057: if (debug)
058: dbg_enter("nameValue");
059: try {
060:
061: lexer.match(LexerCore.ID);
062: Token name = lexer.getNextToken();
063: // eat white space.
064: lexer.SPorHT();
065: try {
066: boolean quoted = false;
067: char la = lexer.lookAhead(0);
068:
069: if (la == separator) {
070: lexer.consume(1);
071: lexer.SPorHT();
072: String str = null;
073: if (lexer.lookAhead(0) == '\"') {
074: str = lexer.quotedString();
075: quoted = true;
076: } else {
077: lexer.match(LexerCore.ID);
078: Token value = lexer.getNextToken();
079: str = value.tokenValue;
080: }
081: NameValue nv = new NameValue(name.tokenValue, str);
082: if (quoted)
083: nv.setQuotedValue();
084: return nv;
085: } else {
086: // if the parameter has no value, an empty string is used
087: return new NameValue(name.tokenValue, "");
088: }
089: } catch (ParseException ex) {
090: return new NameValue(name.tokenValue, "");
091: }
092:
093: } finally {
094: if (debug)
095: dbg_leave("nameValue");
096: }
097:
098: }
099:
100: /**
101: * Beginning of debug operation.
102: * @param rule the name of the rule being evaluated
103: */
104: protected void dbg_enter(String rule) {
105: StringBuffer stringBuffer = new StringBuffer();
106:
107: for (int i = 0; i < nesting_level; i++)
108: stringBuffer.append(">");
109:
110: if (debug) {
111: Logging.report(Logging.INFORMATION, LogChannels.LC_JSR180,
112: stringBuffer + rule + "\nlexer buffer = \n"
113: + lexer.getRest());
114: }
115: nesting_level++;
116: }
117:
118: /**
119: * Completion of diagnostic operation.
120: * @param rule name of the rule being evaluated
121: */
122: protected void dbg_leave(String rule) {
123: StringBuffer stringBuffer = new StringBuffer();
124: for (int i = 0; i < nesting_level; i++)
125: stringBuffer.append("<");
126:
127: if (debug) {
128: Logging.report(Logging.INFORMATION, LogChannels.LC_JSR180,
129: stringBuffer + rule + "\nlexer buffer = \n"
130: + lexer.getRest());
131: }
132: nesting_level--;
133: }
134:
135: /**
136: * Gets name value token using '=' as a separator.
137: * @return the name value token
138: * @exception ParseException if a parsing error occurs
139: */
140: protected NameValue nameValue() throws ParseException {
141: return nameValue('=');
142: }
143:
144: /**
145: * Peeks at the next line.
146: * @param rule the name of the lexer rule to apply
147: */
148: protected void peekLine(String rule) {
149: if (ParserCore.debug) {
150: Logging.report(Logging.INFORMATION, LogChannels.LC_JSR180,
151: rule + " " + lexer.peekLine());
152: }
153: }
154: }
|