/*
*
*
* Copyright 1990-2007 Sun Microsystems, Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version
* 2 only, as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License version 2 for more details (a copy is
* included at /legal/license.txt).
*
* You should have received a copy of the GNU General Public License
* version 2 along with this work; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
* Clara, CA 95054 or visit www.sun.com if you need additional
* information or have any questions.
*/
package gov.nist.siplite.parser;
import java.util.Stack;
import gov.nist.core.*;
import gov.nist.siplite.header.*;
/**
* Parser for content type header.
*
*/
public class ExtensionParser extends ParametersParser {
/** Default constructor. */
protected ExtensionParser() {}
/**
* Constructor with header value.
* @param value full header value respresented as a string
*/
public ExtensionParser(String value) {
super(value);
}
/**
* Constructor with initial lexer engine.
* @param lexer initial lexer engine
*/
protected ExtensionParser(Lexer lexer) {
super(lexer);
}
/**
* Searches a given string for a given character and returns its index.
* This function should be used instead of String.indexOf(char) to handle
* the cases like <br>
* SomeHeader: "Token1; Token2" <sip:something;sip_param>param=value
* <br>
* It will return an index of the ';' located before the "param=value".
* IMPL_NOTE: optimize and think about moving it to Lexer.
* @param buffer a string that will be searched for the delimiter
* @param delimiter a character to look for
* @return an index of the delimiter of -1 if it was not found
*/
private int getDelimiterIndex(String buffer, char delimiter) {
Stack stack = new Stack();
char ch, top;
for (int i = 0; i < buffer.length(); i++) {
ch = buffer.charAt(i);
if (!stack.empty()) {
top = ((Character)stack.peek()).charValue();
} else {
top = '\0';
}
if (ch == '<') {
if (top != '"') {
stack.push(new Character(ch));
}
continue;
}
if (ch == '>') {
if (top == '<') {
stack.pop();
}
continue;
}
if (ch == '"') {
if (top == '"') {
stack.pop();
} else {
stack.push(new Character(ch));
}
continue;
}
if (!stack.empty()) {
continue;
}
if (ch == delimiter) {
return i;
}
}
return -1;
}
/**
* Invokes parser for extension header field.
* IMPL_NOTE: optimize it (maybe use ParserCore.nameValue()?).
* @return the parsed extension header
* @throws ParseException if a parsing error occurs
*/
public Header parse() throws ParseException {
String name = lexer.getNextToken(':');
lexer.consume(1);
lexer.SPorHT();
String bodyWithParam = StringTokenizer.convertNewLines(
lexer.getRest().trim());
char colonDelimiter = ';';
int index = getDelimiterIndex(bodyWithParam, colonDelimiter);
if (index == -1) {
// no parameters were specified
// String body = lexer.getLine().trim();
ExtensionHeader retval = new ExtensionHeader(name,
bodyWithParam, bodyWithParam);
return retval;
} else {
int currPos = lexer.getPtr();
String body = StringTokenizer.convertNewLines(
lexer.getBuffer().substring(currPos, currPos + index).trim());
lexer.consume(index + 1);
lexer.SPorHT();
ExtensionHeader retval = new
ExtensionHeader(name, bodyWithParam, body);
String paramName, paramVal;
boolean headerEnd = false;
int eqIndex, semicolonIndex;
while (!headerEnd) {
paramName = lexer.peekLine().trim();
eqIndex = paramName.indexOf('=');
semicolonIndex = paramName.indexOf(colonDelimiter);
if ((eqIndex != -1) &&
(semicolonIndex > eqIndex || semicolonIndex == -1)) {
// parameter with a value
paramName = lexer.getString('=');
// take the rest of the line
paramVal = lexer.peekLine().trim();
// IMPL_NOTE: remove !!!
// System.out.println("*** Rest is '" + paramVal + "'");
if (paramVal.indexOf(colonDelimiter) != -1) {
paramVal = lexer.getString(colonDelimiter);
} else {
paramVal = lexer.getLine().trim();
headerEnd = true;
}
} else {
if (semicolonIndex != -1) {
// parameter without a value
paramName = lexer.getString(colonDelimiter);
} else {
// the last parameter without a value
paramName = lexer.getLine().trim();
headerEnd = true;
}
paramVal = "";
}
paramName = paramName.trim();
paramVal = paramVal.trim();
// IMPL_NOTE: remove !!!
// System.out.println("*** paramName = " + paramName);
// IMPL_NOTE: remove !!!
// System.out.println(">>> Adding '" +
// paramName + "' = '" + paramVal + "'");
// The following toLowerCase() call is required because
// some 'known' headers (like Accept-Language) haven't
// corresponding implementation classes, but
// ExtensionHeader class is used to represent them.
//
// So, here we have to care about 'known' parameters for
// the mentioned headers. For example, a parameter 'q'
// must be case-insensitive.
paramName = paramName.toLowerCase();
// Validate parameter's name and value
if (!Lexer.isValidName(paramName)) {
throw new ParseException("Invalid parameter's name.", 0);
}
if (!Lexer.isValidParameterValue(paramVal)) {
throw new ParseException("Invalid parameter's value.", 0);
}
if (retval.getParameter(paramName) != null) {
throw new ParseException(
"Duplicated parameter: " + paramName, 0);
}
retval.setParameter(paramName, paramVal);
} // end while()
return retval;
}
}
}
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