/*
* plist - An open source library to parse and generate property lists
* Copyright (C) 2014 Daniel Dreibrodt
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
package com.dd.plist;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.nio.CharBuffer;
import java.nio.charset.CharacterCodingException;
import java.nio.charset.Charset;
import java.nio.charset.CharsetEncoder;
import java.text.ParseException;
import java.text.StringCharacterIterator;
import java.util.LinkedList;
import java.util.List;
/**
* Parser for ASCII property lists. Supports Apple OS X/iOS and GnuStep/NeXTSTEP format.
* This parser is based on the recursive descent paradigm, but the underlying grammar
* is not explicitely defined.
* <p/>
* Resources on ASCII property list format:
* <ul>
* <li><a href="https://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/PropertyLists/OldStylePlists/OldStylePLists.html>
* Property List Programming Guide - Old-Style ASCII Property Lists
* </a></li>
* <li><a href="http://www.gnustep.org/resources/documentation/Developer/Base/Reference/NSPropertyList.html">
* GnuStep - NSPropertyListSerialization class documentation
* </a></li>
* </ul>
*
* @author Daniel Dreibrodt
*/
public class ASCIIPropertyListParser {
/**
* Parses an ASCII property list file.
*
* @param f The ASCII property list file.
* @return The root object of the property list. This is usally a NSDictionary but can also be a NSArray.
* @throws Exception When an error occurs during parsing.
*/
public static NSObject parse(File f) throws IOException, ParseException {
return parse(new FileInputStream(f));
}
/**
* Parses an ASCII property list from an input stream.
*
* @param in The input stream that points to the property list's data.
* @return The root object of the property list. This is usally a NSDictionary but can also be a NSArray.
* @throws Exception When an error occurs during parsing.
*/
public static NSObject parse(InputStream in) throws ParseException, IOException {
byte[] buf = PropertyListParser.readAll(in);
in.close();
return parse(buf);
}
/**
* Parses an ASCII property list from a byte array.
*
* @param bytes The ASCII property list data.
* @return The root object of the property list. This is usally a NSDictionary but can also be a NSArray.
* @throws Exception When an error occurs during parsing.
*/
public static NSObject parse(byte[] bytes) throws ParseException {
ASCIIPropertyListParser parser = new ASCIIPropertyListParser(bytes);
return parser.parse();
}
public static final char WHITESPACE_SPACE = ' ';
public static final char WHITESPACE_TAB = '\t';
public static final char WHITESPACE_NEWLINE = '\n';
public static final char WHITESPACE_CARRIAGE_RETURN = '\r';
public static final char ARRAY_BEGIN_TOKEN = '(';
public static final char ARRAY_END_TOKEN = ')';
public static final char ARRAY_ITEM_DELIMITER_TOKEN = ',';
public static final char DICTIONARY_BEGIN_TOKEN = '{';
public static final char DICTIONARY_END_TOKEN = '}';
public static final char DICTIONARY_ASSIGN_TOKEN = '=';
public static final char DICTIONARY_ITEM_DELIMITER_TOKEN = ';';
public static final char QUOTEDSTRING_BEGIN_TOKEN = '"';
public static final char QUOTEDSTRING_END_TOKEN = '"';
public static final char QUOTEDSTRING_ESCAPE_TOKEN = '\\';
public static final char DATA_BEGIN_TOKEN = '<';
public static final char DATA_END_TOKEN = '>';
public static final char DATA_GSOBJECT_BEGIN_TOKEN = '*';
public static final char DATA_GSDATE_BEGIN_TOKEN = 'D';
public static final char DATA_GSBOOL_BEGIN_TOKEN = 'B';
public static final char DATA_GSBOOL_TRUE_TOKEN = 'Y';
public static final char DATA_GSBOOL_FALSE_TOKEN = 'N';
public static final char DATA_GSINT_BEGIN_TOKEN = 'I';
public static final char DATA_GSREAL_BEGIN_TOKEN = 'R';
public static final char DATE_DATE_FIELD_DELIMITER = '-';
public static final char DATE_TIME_FIELD_DELIMITER = ':';
public static final char DATE_GS_DATE_TIME_DELIMITER = ' ';
public static final char DATE_APPLE_DATE_TIME_DELIMITER = 'T';
public static final char DATE_APPLE_END_TOKEN = 'Z';
public static final char COMMENT_BEGIN_TOKEN = '/';
public static final char MULTILINE_COMMENT_SECOND_TOKEN = '*';
public static final char SINGLELINE_COMMENT_SECOND_TOKEN = '/';
public static final char MULTILINE_COMMENT_END_TOKEN = '/';
/**
* Property list source data
*/
private byte[] data;
/**
* Current parsing index
*/
private int index;
/**
* Only allow subclasses to change instantiation.
*/
protected ASCIIPropertyListParser() {
}
/**
* Creates a new parser for the given property list content.
*
* @param propertyListContent The content of the property list that is to be parsed.
*/
private ASCIIPropertyListParser(byte[] propertyListContent) {
data = propertyListContent;
}
/**
* Checks whether the given sequence of symbols can be accepted.
*
* @param sequence The sequence of tokens to look for.
* @return Whether the given tokens occur at the current parsing position.
*/
private boolean acceptSequence(char... sequence) {
for (int i = 0; i < sequence.length; i++) {
if (data[index + i] != sequence[i])
return false;
}
return true;
}
/**
* Checks whether the given symbols can be accepted, that is, if one
* of the given symbols is found at the current parsing position.
*
* @param acceptableSymbols The symbols to check.
* @return Whether one of the symbols can be accepted or not.
*/
private boolean accept(char... acceptableSymbols) {
boolean symbolPresent = false;
for (char c : acceptableSymbols) {
if (data[index] == c)
symbolPresent = true;
}
return symbolPresent;
}
/**
* Checks whether the given symbol can be accepted, that is, if
* the given symbols is found at the current parsing position.
*
* @param acceptableSymbol The symbol to check.
* @return Whether the symbol can be accepted or not.
*/
private boolean accept(char acceptableSymbol) {
return data[index] == acceptableSymbol;
}
/**
* Expects the input to have one of the given symbols at the current parsing position.
*
* @param expectedSymbols The expected symbols.
* @throws ParseException If none of the expected symbols could be found.
*/
private void expect(char... expectedSymbols) throws ParseException {
if (!accept(expectedSymbols)) {
String excString = "Expected '" + expectedSymbols[0] + "'";
for (int i = 1; i < expectedSymbols.length; i++) {
excString += " or '" + expectedSymbols[i] + "'";
}
excString += " but found '" + (char) data[index] + "'";
throw new ParseException(excString, index);
}
}
/**
* Expects the input to have the given symbol at the current parsing position.
*
* @param expectedSymbol The expected symbol.
* @throws ParseException If the expected symbol could be found.
*/
private void expect(char expectedSymbol) throws ParseException {
if (!accept(expectedSymbol))
throw new ParseException("Expected '" + expectedSymbol + "' but found '" + (char) data[index] + "'", index);
}
/**
* Reads an expected symbol.
*
* @param symbol The symbol to read.
* @throws ParseException If the expected symbol could not be read.
*/
private void read(char symbol) throws ParseException {
expect(symbol);
index++;
}
/**
* Skips the current symbol.
*/
private void skip() {
index++;
}
/**
* Skips several symbols
*
* @param numSymbols The amount of symbols to skip.
*/
private void skip(int numSymbols) {
index += numSymbols;
}
/**
* Skips all whitespaces and comments from the current parsing position onward.
*/
private void skipWhitespacesAndComments() {
boolean commentSkipped;
do {
commentSkipped = false;
//Skip whitespaces
while (accept(WHITESPACE_CARRIAGE_RETURN, WHITESPACE_NEWLINE, WHITESPACE_SPACE, WHITESPACE_TAB)) {
skip();
}
//Skip single line comments "//..."
if (acceptSequence(COMMENT_BEGIN_TOKEN, SINGLELINE_COMMENT_SECOND_TOKEN)) {
skip(2);
readInputUntil(WHITESPACE_CARRIAGE_RETURN, WHITESPACE_NEWLINE);
commentSkipped = true;
}
//Skip multi line comments "/* ... */"
else if (acceptSequence(COMMENT_BEGIN_TOKEN, MULTILINE_COMMENT_SECOND_TOKEN)) {
skip(2);
while (true) {
if (acceptSequence(MULTILINE_COMMENT_SECOND_TOKEN, MULTILINE_COMMENT_END_TOKEN)) {
skip(2);
break;
}
skip();
}
commentSkipped = true;
}
}
while (commentSkipped); //if a comment was skipped more whitespace or another comment can follow, so skip again
}
private String toUtf8String(ByteArrayOutputStream stream) {
try {
return stream.toString("UTF-8");
} catch (UnsupportedEncodingException e) {
throw new RuntimeException(e);
}
}
/**
* Reads input until one of the given symbols is found.
*
* @param symbols The symbols that can occur after the string to read.
* @return The input until one the given symbols.
*/
private String readInputUntil(char... symbols) {
ByteArrayOutputStream stringBytes = new ByteArrayOutputStream();
while (!accept(symbols)) {
stringBytes.write(data[index]);
skip();
}
return toUtf8String(stringBytes);
}
/**
* Reads input until the given symbol is found.
*
* @param symbol The symbol that can occur after the string to read.
* @return The input until the given symbol.
*/
private String readInputUntil(char symbol) {
ByteArrayOutputStream stringBytes = new ByteArrayOutputStream();
while (!accept(symbol)) {
stringBytes.write(data[index]);
skip();
}
return toUtf8String(stringBytes);
}
/**
* Parses the property list from the beginning and returns the root object
* of the property list.
*
* @return The root object of the property list. This can either be a NSDictionary or a NSArray.
* @throws ParseException When an error occured during parsing
*/
public NSObject parse() throws ParseException {
index = 0;
skipWhitespacesAndComments();
expect(DICTIONARY_BEGIN_TOKEN, ARRAY_BEGIN_TOKEN, COMMENT_BEGIN_TOKEN);
try {
return parseObject();
} catch (ArrayIndexOutOfBoundsException ex) {
throw new ParseException("Reached end of input unexpectedly.", index);
}
}
/**
* Parses the NSObject found at the current position in the property list
* data stream.
*
* @return The parsed NSObject.
* @see ASCIIPropertyListParser#index
*/
private NSObject parseObject() throws ParseException {
switch (data[index]) {
case ARRAY_BEGIN_TOKEN: {
return parseArray();
}
case DICTIONARY_BEGIN_TOKEN: {
return parseDictionary();
}
case DATA_BEGIN_TOKEN: {
return parseData();
}
case QUOTEDSTRING_BEGIN_TOKEN: {
String quotedString = parseQuotedString();
//apple dates are quoted strings of length 20 and after the 4 year digits a dash is found
if (quotedString.length() == 20 && quotedString.charAt(4) == DATE_DATE_FIELD_DELIMITER) {
try {
return new NSDate(quotedString);
} catch (Exception ex) {
//not a date? --> return string
return new NSString(quotedString);
}
} else {
return new NSString(quotedString);
}
}
default: {
//0-9
if (data[index] > 0x2F && data[index] < 0x3A) {
//could be a date or just a string
return parseDateString();
} else {
//non-numerical -> string or boolean
String parsedString = parseString();
return new NSString(parsedString);
}
}
}
}
/**
* Parses an array from the current parsing position.
* The prerequisite for calling this method is, that an array begin token has been read.
*
* @return The array found at the parsing position.
*/
private NSArray parseArray() throws ParseException {
//Skip begin token
skip();
skipWhitespacesAndComments();
List<NSObject> objects = new LinkedList<NSObject>();
while (!accept(ARRAY_END_TOKEN)) {
objects.add(parseObject());
skipWhitespacesAndComments();
if (accept(ARRAY_ITEM_DELIMITER_TOKEN)) {
skip();
} else {
break; //must have reached end of array
}
skipWhitespacesAndComments();
}
//parse end token
read(ARRAY_END_TOKEN);
return new NSArray(objects.toArray(new NSObject[objects.size()]));
}
/**
* Parses a dictionary from the current parsing position.
* The prerequisite for calling this method is, that a dictionary begin token has been read.
*
* @return The dictionary found at the parsing position.
*/
private NSDictionary parseDictionary() throws ParseException {
//Skip begin token
skip();
skipWhitespacesAndComments();
NSDictionary dict = new NSDictionary();
while (!accept(DICTIONARY_END_TOKEN)) {
//Parse key
String keyString;
if (accept(QUOTEDSTRING_BEGIN_TOKEN)) {
keyString = parseQuotedString();
} else {
keyString = parseString();
}
skipWhitespacesAndComments();
//Parse assign token
read(DICTIONARY_ASSIGN_TOKEN);
skipWhitespacesAndComments();
NSObject object = parseObject();
dict.put(keyString, object);
skipWhitespacesAndComments();
read(DICTIONARY_ITEM_DELIMITER_TOKEN);
skipWhitespacesAndComments();
}
//skip end token
skip();
return dict;
}
/**
* Parses a data object from the current parsing position.
* This can either be a NSData object or a GnuStep NSNumber or NSDate.
* The prerequisite for calling this method is, that a data begin token has been read.
*
* @return The data object found at the parsing position.
*/
private NSObject parseData() throws ParseException {
NSObject obj = null;
//Skip begin token
skip();
if (accept(DATA_GSOBJECT_BEGIN_TOKEN)) {
skip();
expect(DATA_GSBOOL_BEGIN_TOKEN, DATA_GSDATE_BEGIN_TOKEN, DATA_GSINT_BEGIN_TOKEN, DATA_GSREAL_BEGIN_TOKEN);
if (accept(DATA_GSBOOL_BEGIN_TOKEN)) {
//Boolean
skip();
expect(DATA_GSBOOL_TRUE_TOKEN, DATA_GSBOOL_FALSE_TOKEN);
if (accept(DATA_GSBOOL_TRUE_TOKEN)) {
obj = new NSNumber(true);
} else {
obj = new NSNumber(false);
}
//Skip the parsed boolean token
skip();
} else if (accept(DATA_GSDATE_BEGIN_TOKEN)) {
//Date
skip();
String dateString = readInputUntil(DATA_END_TOKEN);
obj = new NSDate(dateString);
} else if (accept(DATA_GSINT_BEGIN_TOKEN, DATA_GSREAL_BEGIN_TOKEN)) {
//Number
skip();
String numberString = readInputUntil(DATA_END_TOKEN);
obj = new NSNumber(numberString);
}
//parse data end token
read(DATA_END_TOKEN);
} else {
String dataString = readInputUntil(DATA_END_TOKEN);
dataString = dataString.replaceAll("\\s+", "");
int numBytes = dataString.length() / 2;
byte[] bytes = new byte[numBytes];
for (int i = 0; i < bytes.length; i++) {
String byteString = dataString.substring(i * 2, i * 2 + 2);
int byteValue = Integer.parseInt(byteString, 16);
bytes[i] = (byte) byteValue;
}
obj = new NSData(bytes);
//skip end token
skip();
}
return obj;
}
/**
* Attempts to parse a plain string as a date if possible.
*
* @return A NSDate if the string represents such an object. Otherwise a NSString is returned.
*/
private NSObject parseDateString() {
String numericalString = parseString();
if (numericalString.length() > 4 && numericalString.charAt(4) == DATE_DATE_FIELD_DELIMITER) {
try {
return new NSDate(numericalString);
} catch(Exception ex) {
//An exception occurs if the string is not a date but just a string
}
}
return new NSString(numericalString);
}
/**
* Parses a plain string from the current parsing position.
* The string is made up of all characters to the next whitespace, delimiter token or assignment token.
*
* @return The string found at the current parsing position.
*/
private String parseString() {
return readInputUntil(WHITESPACE_SPACE, WHITESPACE_TAB, WHITESPACE_NEWLINE, WHITESPACE_CARRIAGE_RETURN,
ARRAY_ITEM_DELIMITER_TOKEN, DICTIONARY_ITEM_DELIMITER_TOKEN, DICTIONARY_ASSIGN_TOKEN, ARRAY_END_TOKEN);
}
/**
* Parses a quoted string from the current parsing position.
* The prerequisite for calling this method is, that a quoted string begin token has been read.
*
* @return The quoted string found at the parsing method with all special characters unescaped.
* @throws ParseException If an error occured during parsing.
*/
private String parseQuotedString() throws ParseException {
//Skip begin token
skip();
ByteArrayOutputStream quotedString = new ByteArrayOutputStream();
boolean unescapedBackslash = true;
//Read from opening quotation marks to closing quotation marks and skip escaped quotation marks
while (data[index] != QUOTEDSTRING_END_TOKEN || (data[index - 1] == QUOTEDSTRING_ESCAPE_TOKEN && unescapedBackslash)) {
quotedString.write(data[index]);
if (accept(QUOTEDSTRING_ESCAPE_TOKEN)) {
unescapedBackslash = !(data[index - 1] == QUOTEDSTRING_ESCAPE_TOKEN && unescapedBackslash);
}
skip();
}
String unescapedString;
try {
unescapedString = parseQuotedString(toUtf8String(quotedString));
} catch (Exception ex) {
throw new ParseException("The quoted string could not be parsed.", index);
}
//skip end token
skip();
return unescapedString;
}
/**
* Used to encode the parsed strings
*/
private static CharsetEncoder asciiEncoder;
/**
* Parses a string according to the format specified for ASCII property lists.
* Such strings can contain escape sequences which are unescaped in this method.
*
* @param s The escaped string according to the ASCII property list format, without leading and trailing quotation marks.
* @return The unescaped string in UTF-8 or ASCII format, depending on the contained characters.
* @throws Exception If the string could not be properly parsed.
*/
public static synchronized String parseQuotedString(String s) throws UnsupportedEncodingException, CharacterCodingException {
StringBuilder parsed = new StringBuilder();
StringCharacterIterator iterator = new StringCharacterIterator(s);
char c = iterator.current();
while (iterator.getIndex() < iterator.getEndIndex()) {
switch (c) {
case '\\': { //An escaped sequence is following
parsed.append(parseEscapedSequence(iterator));
break;
}
default: {
parsed.append(c);
break;
}
}
c = iterator.next();
}
return parsed.toString();
}
/**
* Unescapes an escaped character sequence, e.g. \\u00FC.
*
* @param iterator The string character iterator pointing to the first character after the backslash
* @return The unescaped character
*/
private static char parseEscapedSequence(StringCharacterIterator iterator) {
char c = iterator.next();
if (c == 'b') {
return '\b';
} else if (c == 'n') {
return '\n';
} else if (c == 'r') {
return '\r';
} else if (c == 't') {
return '\t';
} else if (c == 'U' || c == 'u') {
//4 digit hex Unicode value
String byte1 = "";
byte1 += iterator.next();
byte1 += iterator.next();
String byte2 = "";
byte2 += iterator.next();
byte2 += iterator.next();
return (char) ((Integer.parseInt(byte1, 16) << 8) + Integer.parseInt(byte2, 16));
} else if ((c >= '0') && (c <= '7')) {
//3 digit octal ASCII value
String num = "";
num += c;
num += iterator.next();
num += iterator.next();
return (char) Integer.parseInt(num, 8);
} else {
// Possibly something that needn't be escaped, but we should accept it
// it anyway for consistency with Apple tools.
return c;
}
}
}