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The Apache Commons Codec package contains simple encoder and decoders for
various formats such as Base64 and Hexadecimal. In addition to these
widely used encoders and decoders, the codec package also maintains a
collection of phonetic encoding utilities.
/* ====================================================================
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.poi.hdgf.chunks;
import java.util.ArrayList;
import org.apache.poi.hdgf.chunks.ChunkFactory.CommandDefinition;
import org.apache.poi.util.LittleEndian;
import org.apache.poi.util.POILogFactory;
import org.apache.poi.util.POILogger;
/**
* Base of all chunks, which hold data, flags etc
*/
public final class Chunk {
/**
* The contents of the chunk, excluding the header,
* trailer and separator
*/
private byte[] contents;
private ChunkHeader header;
/** May be null */
private ChunkTrailer trailer;
/** May be null */
private ChunkSeparator separator;
/** The possible different commands we can hold */
private CommandDefinition[] commandDefinitions;
/** The command+value pairs we hold */
private Command[] commands;
/* The blocks (if any) we hold */
//private Block[] blocks
/** The name of the chunk, as found from the commandDefinitions */
private String name;
/** For logging warnings about the structure of the file */
private POILogger logger = POILogFactory.getLogger(Chunk.class);
public Chunk(ChunkHeader header, ChunkTrailer trailer, ChunkSeparator separator, byte[] contents) {
this.header = header;
this.trailer = trailer;
this.separator = separator;
this.contents = contents.clone();
}
public byte[] _getContents() {
return contents;
}
public ChunkHeader getHeader() {
return header;
}
/**
* Gets the separator between this chunk and the next, if it exists
*
* @return the separator
*/
public ChunkSeparator getSeparator() {
return separator;
}
/**
* Gets the trailer for this chunk, if it exists
*
* @return the trailer
*/
public ChunkTrailer getTrailer() {
return trailer;
}
/**
* Gets the command definitions, which define and describe much
* of the data held by the chunk.
*
* @return the command definitions
*/
@SuppressWarnings("unused")
public CommandDefinition[] getCommandDefinitions() {
return commandDefinitions;
}
void setCommandDefinitions(CommandDefinition[] commandDefinitions) {
this.commandDefinitions = commandDefinitions;
}
public Command[] getCommands() {
return commands;
}
/**
* Get the name of the chunk, as found from the CommandDefinitions
*
* @return the name of the chunk
*/
public String getName() {
return name;
}
/**
* Returns the size of the chunk, including any
* headers, trailers and separators.
*
* @return the size of the chunk
*/
public int getOnDiskSize() {
int size = header.getSizeInBytes() + contents.length;
if(trailer != null) {
size += trailer.getTrailerData().length;
}
if(separator != null) {
size += separator.separatorData.length;
}
return size;
}
/**
* Uses our CommandDefinitions to process the commands
* our chunk type has, and figure out the
* values for them.
*/
void processCommands() {
if(commandDefinitions == null) {
throw new IllegalStateException("You must supply the command definitions before calling processCommands!");
}
// Loop over the definitions, building the commands
// and getting their values
ArrayList commandList = new ArrayList<>();
for(CommandDefinition cdef : commandDefinitions) {
int type = cdef.getType();
int offset = cdef.getOffset();
// Handle virtual commands
if(type == 10) {
name = cdef.getName();
continue;
} else if(type == 18) {
continue;
}
// Build the appropriate command for the type
Command command;
if(type == 11 || type == 21) {
command = new BlockOffsetCommand(cdef);
} else {
command = new Command(cdef);
}
// Bizarrely, many of the offsets are from the start of the
// header, not from the start of the chunk body
switch(type) {
case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7:
case 11: case 21:
case 12: case 16: case 17: case 28: case 29:
// Offset is from start of chunk (case 18 has been taken care of above)
break;
default:
// Offset is from start of header!
if(offset >= 19) {
offset -= 19;
}
}
// Check we seem to have enough data
if(offset >= contents.length) {
logger.log(POILogger.WARN,
"Command offset ", offset, " past end of data at ", contents.length
);
continue;
}
try {
// Process
switch(type) {
// Types 0->7 = a flag at bit 0->7
case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7:
command.value = ((contents[offset] >>> type) & 1) == 1;
break;
case 8:
command.value = contents[offset];
break;
case 9:
command.value = LittleEndian.getDouble(contents, offset);
break;
case 12:
// A Little Endian String
// Starts 8 bytes into the data segment
// Ends at end of data, or 00 00
// Ensure we have enough data
if(contents.length < 8) {
command.value = "";
break;
}
// Find the end point
int startsAt = 8;
int endsAt = startsAt;
for(int j=startsAt; j