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This library enables Java applications to work with property lists in various formats.
Supported formats for reading and writing are OS X/iOS binary and XML property lists.
ASCII property lists are also supported.
The library also provides access to basic functions of NeXTSTEP/Cocoa classes like
NSDictionary, NSArray, etc.
/*
* plist - An open source library to parse and generate property lists
* Copyright (C) 2012 Keith Randall
*
* 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.BufferedOutputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.LinkedHashMap;
import java.util.Map;
/**
* A BinaryPropertyListWriter is a helper class for writing out
* binary property list files. It contains an output stream and
* various structures for keeping track of which NSObjects have
* already been serialized, and where they were put in the file.
*
* @author Keith Randall
*/
public final class BinaryPropertyListWriter {
private static final int VERSION_00 = 0;
private static final int VERSION_10 = 10;
private static final int VERSION_15 = 15;
private static final int VERSION_20 = 20;
private int version = VERSION_00;
// raw output stream to result file
private final OutputStream out;
// # of bytes written so far
private long count;
// map from object to its ID
private final Map idMap = new LinkedHashMap();
private int idSizeInBytes;
/**
* Creates a new binary property list writer
*
* @param outStr The output stream into which the binary property list will be written
* @throws IOException When an IO error occurs while writing to the stream or the object structure contains
* data that cannot be saved.
*/
BinaryPropertyListWriter(OutputStream outStr) throws IOException {
out = new BufferedOutputStream(outStr);
}
BinaryPropertyListWriter(OutputStream outStr, int version) throws IOException {
this.version = version;
out = new BufferedOutputStream(outStr);
}
/**
* Finds out the minimum binary property list format version that
* can be used to save the given NSObject tree.
*
* @param root Object root
* @return Version code
*/
private static int getMinimumRequiredVersion(NSObject root) {
int minVersion = VERSION_00;
if (root == null) {
minVersion = VERSION_10;
}
if (root instanceof NSDictionary) {
NSDictionary dict = (NSDictionary) root;
for (NSObject o : dict.getHashMap().values()) {
int v = getMinimumRequiredVersion(o);
if (v > minVersion)
minVersion = v;
}
} else if (root instanceof NSArray) {
NSArray array = (NSArray) root;
for (NSObject o : array.getArray()) {
int v = getMinimumRequiredVersion(o);
if (v > minVersion)
minVersion = v;
}
} else if (root instanceof NSSet) {
//Sets are only allowed in property lists v1+
minVersion = VERSION_10;
NSSet set = (NSSet) root;
for (NSObject o : set.allObjects()) {
int v = getMinimumRequiredVersion(o);
if (v > minVersion)
minVersion = v;
}
}
return minVersion;
}
/**
* Writes a binary plist file with the given object as the root.
*
* @param file the file to write to
* @param root the source of the data to write to the file
* @throws IOException When an IO error occurs while writing to the file or the object structure contains
* data that cannot be saved.
*/
public static void write(File file, NSObject root) throws IOException {
OutputStream out = new FileOutputStream(file);
write(out, root);
out.close();
}
/**
* Writes a binary plist serialization of the given object as the root.
*
* @param out the stream to write to
* @param root the source of the data to write to the stream
* @throws IOException When an IO error occurs while writing to the stream or the object structure contains
* data that cannot be saved.
*/
public static void write(OutputStream out, NSObject root) throws IOException {
int minVersion = getMinimumRequiredVersion(root);
if (minVersion > VERSION_00) {
String versionString = minVersion == VERSION_10 ? "v1.0" : (minVersion == VERSION_15 ? "v1.5" : (minVersion == VERSION_20 ? "v2.0" : "v0.0"));
throw new IOException("The given property list structure cannot be saved. " +
"The required version of the binary format (" + versionString + ") is not yet supported.");
}
BinaryPropertyListWriter w = new BinaryPropertyListWriter(out, minVersion);
w.write(root);
}
/**
* Writes a binary plist serialization of the given object as the root
* into a byte array.
*
* @param root The root object of the property list
* @return The byte array containing the serialized property list
* @throws IOException When an IO error occurs while writing to the stream or the object structure contains
* data that cannot be saved.
*/
public static byte[] writeToArray(NSObject root) throws IOException {
ByteArrayOutputStream bout = new ByteArrayOutputStream();
write(bout, root);
return bout.toByteArray();
}
void write(NSObject root) throws IOException {
// magic bytes
write(new byte[]{'b', 'p', 'l', 'i', 's', 't'});
//version
switch (version) {
case VERSION_00: {
write(new byte[]{'0', '0'});
break;
}
case VERSION_10: {
write(new byte[]{'1', '0'});
break;
}
case VERSION_15: {
write(new byte[]{'1', '5'});
break;
}
case VERSION_20: {
write(new byte[]{'2', '0'});
break;
}
default:
break;
}
// assign IDs to all the objects.
root.assignIDs(this);
idSizeInBytes = computeIdSizeInBytes(idMap.size());
// offsets of each object, indexed by ID
long[] offsets = new long[idMap.size()];
// write each object, save offset
for (Map.Entry entry : idMap.entrySet()) {
NSObject obj = entry.getKey();
int id = entry.getValue();
offsets[id] = count;
if (obj == null) {
write(0x00);
} else {
obj.toBinary(this);
}
}
// write offset table
long offsetTableOffset = count;
int offsetSizeInBytes = computeOffsetSizeInBytes(count);
for (long offset : offsets) {
writeBytes(offset, offsetSizeInBytes);
}
if (version != VERSION_15) {
// write trailer
// 6 null bytes
write(new byte[6]);
// size of an offset
write(offsetSizeInBytes);
// size of a ref
write(idSizeInBytes);
// number of objects
writeLong(idMap.size());
// top object
writeLong(idMap.get(root));
// offset table offset
writeLong(offsetTableOffset);
}
out.flush();
}
void assignID(NSObject obj) {
if (!idMap.containsKey(obj)) {
idMap.put(obj, idMap.size());
}
}
int getID(NSObject obj) {
return idMap.get(obj);
}
private static int computeIdSizeInBytes(int numberOfIds) {
if (numberOfIds < 256) return 1;
if (numberOfIds < 65536) return 2;
return 4;
}
private int computeOffsetSizeInBytes(long maxOffset) {
if (maxOffset < 256) return 1;
if (maxOffset < 65536) return 2;
if (maxOffset < 4294967296L) return 4;
return 8;
}
void writeIntHeader(int kind, int value) throws IOException {
assert value >= 0;
if (value < 15) {
write((kind << 4) + value);
} else if (value < 256) {
write((kind << 4) + 15);
write(0x10);
writeBytes(value, 1);
} else if (value < 65536) {
write((kind << 4) + 15);
write(0x11);
writeBytes(value, 2);
} else {
write((kind << 4) + 15);
write(0x12);
writeBytes(value, 4);
}
}
void write(int b) throws IOException {
out.write(b);
count++;
}
void write(byte[] bytes) throws IOException {
out.write(bytes);
count += bytes.length;
}
void writeBytes(long value, int bytes) throws IOException {
// write low-order bytes big-endian style
for (int i = bytes - 1; i >= 0; i--) {
write((int) (value >> (8 * i)));
}
}
void writeID(int id) throws IOException {
writeBytes(id, idSizeInBytes);
}
void writeLong(long value) throws IOException {
writeBytes(value, 8);
}
void writeDouble(double value) throws IOException {
writeLong(Double.doubleToRawLongBits(value));
}
}