/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.tomcat.util.http.fileupload;
import java.io.UnsupportedEncodingException;
import java.util.HashMap;
import java.util.Locale;
import java.util.Map;
import org.apache.tomcat.util.http.fileupload.util.mime.MimeUtility;
/**
* A simple parser intended to parse sequences of name/value pairs.
*
* Parameter values are expected to be enclosed in quotes if they
* contain unsafe characters, such as '=' characters or separators.
* Parameter values are optional and can be omitted.
*
* <p>
* {@code param1 = value; param2 = "anything goes; really"; param3}
* </p>
*/
public class ParameterParser {
/**
* String to be parsed.
*/
private char[] chars;
/**
* Current position in the string.
*/
private int pos;
/**
* Maximum position in the string.
*/
private int len;
/**
* Start of a token.
*/
private int i1;
/**
* End of a token.
*/
private int i2;
/**
* Whether names stored in the map should be converted to lower case.
*/
private boolean lowerCaseNames;
/**
* Default ParameterParser constructor.
*/
public ParameterParser() {
}
/**
* A helper method to process the parsed token. This method removes
* leading and trailing blanks as well as enclosing quotation marks,
* when necessary.
*
* @param quoted {@code true} if quotation marks are expected,
* {@code false} otherwise.
* @return the token
*/
private String getToken(final boolean quoted) {
// Trim leading white spaces
while (i1 < i2 && Character.isWhitespace(chars[i1])) {
i1++;
}
// Trim trailing white spaces
while (i2 > i1 && Character.isWhitespace(chars[i2 - 1])) {
i2--;
}
// Strip away quotation marks if necessary
if (quoted
&& i2 - i1 >= 2
&& chars[i1] == '"'
&& chars[i2 - 1] == '"') {
i1++;
i2--;
}
String result = null;
if (i2 > i1) {
result = new String(chars, i1, i2 - i1);
}
return result;
}
/**
* Are there any characters left to parse?
*
* @return {@code true} if there are unparsed characters,
* {@code false} otherwise.
*/
private boolean hasChar() {
return pos < len;
}
/**
* Returns {@code true} if parameter names are to be converted to lower
* case when name/value pairs are parsed.
*
* @return {@code true} if parameter names are to be
* converted to lower case when name/value pairs are parsed.
* Otherwise returns {@code false}
*/
public boolean isLowerCaseNames() {
return lowerCaseNames;
}
/**
* Tests if the given character is present in the array of characters.
*
* @param ch the character to test for presence in the array of characters
* @param charray the array of characters to test against
*
* @return {@code true} if the character is present in the array of
* characters, {@code false} otherwise.
*/
private boolean isOneOf(final char ch, final char[] charray) {
boolean result = false;
for (final char element : charray) {
if (ch == element) {
result = true;
break;
}
}
return result;
}
/**
* Extracts a map of name/value pairs from the given array of
* characters. Names are expected to be unique.
*
* @param charArray the array of characters that contains a sequence of
* name/value pairs
* @param separator the name/value pairs separator
*
* @return a map of name/value pairs
*/
public Map<String, String> parse(final char[] charArray, final char separator) {
if (charArray == null) {
return new HashMap<>();
}
return parse(charArray, 0, charArray.length, separator);
}
/**
* Extracts a map of name/value pairs from the given array of characters. Names are expected to be unique.
*
* @param charArray the array of characters that contains a sequence of name/value pairs
* @param offset the initial offset.
* @param length the length.
* @param separator the name/value pairs separator
*
* @return a map of name/value pairs
*/
public Map<String, String> parse(final char[] charArray, final int offset, final int length, final char separator) {
if (charArray == null) {
return new HashMap<>();
}
final HashMap<String, String> params = new HashMap<>();
chars = charArray.clone();
pos = offset;
len = length;
while (hasChar()) {
String paramName = parseToken(new char[] { '=', separator });
String paramValue = null;
if (hasChar() && charArray[pos] == '=') {
pos++; // skip '='
paramValue = parseQuotedToken(new char[] { separator });
if (paramValue != null) {
try {
paramValue = RFC2231Utility.hasEncodedValue(paramName) ? RFC2231Utility.decodeText(paramValue)
: MimeUtility.decodeText(paramValue);
} catch (final UnsupportedEncodingException e) {
// let's keep the original value in this case
}
}
}
if (hasChar() && charArray[pos] == separator) {
pos++; // skip separator
}
if (paramName != null && !paramName.isEmpty()) {
paramName = RFC2231Utility.stripDelimiter(paramName);
if (lowerCaseNames) {
paramName = paramName.toLowerCase(Locale.ROOT);
}
params.put(paramName, paramValue);
}
}
return params;
}
/**
* Extracts a map of name/value pairs from the given string. Names are
* expected to be unique.
*
* @param str the string that contains a sequence of name/value pairs
* @param separator the name/value pairs separator
*
* @return a map of name/value pairs
*/
public Map<String, String> parse(final String str, final char separator) {
if (str == null) {
return new HashMap<>();
}
return parse(str.toCharArray(), separator);
}
/**
* Extracts a map of name/value pairs from the given string. Names are
* expected to be unique. Multiple separators may be specified and
* the earliest found in the input string is used.
*
* @param str the string that contains a sequence of name/value pairs
* @param separators the name/value pairs separators
*
* @return a map of name/value pairs
*/
public Map<String, String> parse(final String str, final char[] separators) {
if (separators == null || separators.length == 0) {
return new HashMap<>();
}
char separator = separators[0];
if (str != null) {
int idx = str.length();
for (final char separator2 : separators) {
final int tmp = str.indexOf(separator2);
if (tmp != -1 && tmp < idx) {
idx = tmp;
separator = separator2;
}
}
}
return parse(str, separator);
}
/**
* Parses out a token until any of the given terminators
* is encountered outside the quotation marks.
*
* @param terminators the array of terminating characters. Any of these
* characters when encountered outside the quotation marks signify the end
* of the token
*
* @return the token
*/
private String parseQuotedToken(final char[] terminators) {
char ch;
i1 = pos;
i2 = pos;
boolean quoted = false;
boolean charEscaped = false;
while (hasChar()) {
ch = chars[pos];
if (!quoted && isOneOf(ch, terminators)) {
break;
}
if (!charEscaped && ch == '"') {
quoted = !quoted;
}
charEscaped = !charEscaped && ch == '\\';
i2++;
pos++;
}
return getToken(true);
}
/**
* Parses out a token until any of the given terminators
* is encountered.
*
* @param terminators the array of terminating characters. Any of these
* characters when encountered signify the end of the token
*
* @return the token
*/
private String parseToken(final char[] terminators) {
char ch;
i1 = pos;
i2 = pos;
while (hasChar()) {
ch = chars[pos];
if (isOneOf(ch, terminators)) {
break;
}
i2++;
pos++;
}
return getToken(false);
}
/**
* Sets the flag if parameter names are to be converted to lower case when
* name/value pairs are parsed.
*
* @param b {@code true} if parameter names are to be
* converted to lower case when name/value pairs are parsed.
* {@code false} otherwise.
*/
public void setLowerCaseNames(final boolean b) {
lowerCaseNames = b;
}
}