org.eclipse.jetty.http.QuotedCSVParser Maven / Gradle / Ivy
//
// ========================================================================
// Copyright (c) 1995 Mort Bay Consulting Pty Ltd and others.
//
// This program and the accompanying materials are made available under the
// terms of the Eclipse Public License v. 2.0 which is available at
// https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
// which is available at https://www.apache.org/licenses/LICENSE-2.0.
//
// SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
// ========================================================================
//
package org.eclipse.jetty.http;
/**
* Implements a quoted comma separated list parser
* in accordance with RFC7230.
* OWS is removed and quoted characters ignored for parsing.
*
* @see "https://tools.ietf.org/html/rfc7230#section-3.2.6"
* @see "https://tools.ietf.org/html/rfc7230#section-7"
*/
public abstract class QuotedCSVParser
{
private enum State
{
VALUE, PARAM_NAME, PARAM_VALUE
}
protected final boolean _keepQuotes;
public QuotedCSVParser(boolean keepQuotes)
{
_keepQuotes = keepQuotes;
}
public static String unquote(String s)
{
// handle trivial cases
int l = s.length();
if (s == null || l == 0)
return s;
// Look for any quotes
int i = 0;
for (; i < l; i++)
{
char c = s.charAt(i);
if (c == '"')
break;
}
if (i == l)
return s;
boolean quoted = true;
boolean sloshed = false;
StringBuffer buffer = new StringBuffer();
buffer.append(s, 0, i);
i++;
for (; i < l; i++)
{
char c = s.charAt(i);
if (quoted)
{
if (sloshed)
{
buffer.append(c);
sloshed = false;
}
else if (c == '"')
quoted = false;
else if (c == '\\')
sloshed = true;
else
buffer.append(c);
}
else if (c == '"')
quoted = true;
else
buffer.append(c);
}
return buffer.toString();
}
/**
* Add and parse a value string(s)
*
* @param value A value that may contain one or more Quoted CSV items.
*/
public void addValue(String value)
{
if (value == null)
return;
StringBuffer buffer = new StringBuffer();
int l = value.length();
State state = State.VALUE;
boolean quoted = false;
boolean sloshed = false;
int nwsLength = 0;
int lastLength = 0;
int valueLength = -1;
int paramName = -1;
int paramValue = -1;
for (int i = 0; i <= l; i++)
{
char c = i == l ? 0 : value.charAt(i);
// Handle quoting https://tools.ietf.org/html/rfc7230#section-3.2.6
if (quoted && c != 0)
{
if (sloshed)
sloshed = false;
else
{
switch (c)
{
case '\\':
sloshed = true;
if (!_keepQuotes)
continue;
break;
case '"':
quoted = false;
if (!_keepQuotes)
continue;
break;
default:
break;
}
}
buffer.append(c);
nwsLength = buffer.length();
continue;
}
// Handle common cases
switch (c)
{
case ' ':
case '\t':
if (buffer.length() > lastLength) // not leading OWS
buffer.append(c);
continue;
case '"':
quoted = true;
if (_keepQuotes)
{
if (state == State.PARAM_VALUE && paramValue < 0)
paramValue = nwsLength;
buffer.append(c);
}
else if (state == State.PARAM_VALUE && paramValue < 0)
paramValue = nwsLength;
nwsLength = buffer.length();
continue;
case ';':
buffer.setLength(nwsLength); // trim following OWS
if (state == State.VALUE)
{
parsedValue(buffer);
valueLength = buffer.length();
}
else
parsedParam(buffer, valueLength, paramName, paramValue);
nwsLength = buffer.length();
paramName = paramValue = -1;
buffer.append(c);
lastLength = ++nwsLength;
state = State.PARAM_NAME;
continue;
case ',':
case 0:
if (nwsLength > 0)
{
buffer.setLength(nwsLength); // trim following OWS
switch (state)
{
case VALUE:
parsedValue(buffer);
valueLength = buffer.length();
break;
case PARAM_NAME:
case PARAM_VALUE:
parsedParam(buffer, valueLength, paramName, paramValue);
break;
default:
throw new IllegalStateException(state.toString());
}
parsedValueAndParams(buffer);
}
buffer.setLength(0);
lastLength = 0;
nwsLength = 0;
valueLength = paramName = paramValue = -1;
state = State.VALUE;
continue;
case '=':
switch (state)
{
case VALUE:
// It wasn't really a value, it was a param name
paramName = 0;
buffer.setLength(nwsLength); // trim following OWS
final String param = buffer.toString();
buffer.setLength(0);
parsedValue(buffer);
valueLength = buffer.length();
buffer.append(param);
buffer.append(c);
lastLength = ++nwsLength;
state = State.PARAM_VALUE;
continue;
case PARAM_NAME:
buffer.setLength(nwsLength); // trim following OWS
buffer.append(c);
lastLength = ++nwsLength;
state = State.PARAM_VALUE;
continue;
case PARAM_VALUE:
if (paramValue < 0)
paramValue = nwsLength;
buffer.append(c);
nwsLength = buffer.length();
continue;
default:
throw new IllegalStateException(state.toString());
}
default:
{
switch (state)
{
case VALUE:
{
buffer.append(c);
nwsLength = buffer.length();
continue;
}
case PARAM_NAME:
{
if (paramName < 0)
paramName = nwsLength;
buffer.append(c);
nwsLength = buffer.length();
continue;
}
case PARAM_VALUE:
{
if (paramValue < 0)
paramValue = nwsLength;
buffer.append(c);
nwsLength = buffer.length();
continue;
}
default:
throw new IllegalStateException(state.toString());
}
}
}
}
}
/**
* Called when a value and it's parameters has been parsed
*
* @param buffer Containing the trimmed value and parameters
*/
protected void parsedValueAndParams(StringBuffer buffer)
{
}
/**
* Called when a value has been parsed (prior to any parameters)
*
* @param buffer Containing the trimmed value, which may be mutated
*/
protected void parsedValue(StringBuffer buffer)
{
}
/**
* Called when a parameter has been parsed
*
* @param buffer Containing the trimmed value and all parameters, which may be mutated
* @param valueLength The length of the value
* @param paramName The index of the start of the parameter just parsed
* @param paramValue The index of the start of the parameter value just parsed, or -1
*/
protected void parsedParam(StringBuffer buffer, int valueLength, int paramName, int paramValue)
{
}
}