ACTIONSCRIPT 3 Developer’s Guide en

ACTIONSCRIPT 3.0 DEVELOPER’S GUIDE
Working with byte arrays
//for each node in orderXML
for each(var child:XML in orderXML) {
// append child node to text area
myTxt.text += child + "\n";
}
// for Flex version: } // end of init() // read specified file into byte array
function readFile(fileName:String, data:ByteArray) {
var inFile:File = File.desktopDirectory; // source folder is desktop
inFile = inFile.resolvePath(fileName); // name of file to read
var inStream:FileStream = new FileStream();
inStream.open(inFile, FileMode.READ);
inStream.readBytes(data, 0, data.length);
inStream.close();
}
/* Add the following lines, minus comment characters, for Flex:
* ]]>
*
*
*
*/
ByteArray example: Reading a .zip file
Adobe AIR 1.0 and later
This example demonstrates how to read a simple .zip file containing several files of different types. It does so by
extracting relevant data from the metadata for each file, uncompressing each file into a ByteArray and writing the file
to the desktop.
The general structure of a .zip file is based on the specification by PKWARE Inc., which is maintained at
http://www.pkware.com/documents/casestudies/APPNOTE.TXT. First is a file header and file data for the first file in
the .zip archive, followed by a file header and file data pair for each additional file. (The structure of the file header is
described later.) Next, the .zip file optionally includes a data descriptor record (usually when the output zip file was
created in memory rather than saved to a disk). Next are several additional optional elements: archive decryption
header, archive extra data record, central directory structure, Zip64 end of central directory record, Zip64 end of
central directory locator, and end of central directory record.
The code in this example is written to only parse zip files that do not contain folders and it does not expect data
descriptor records. It ignores all information following the last file data.
The format of the file header for each file is as follows:
file header signature 4 bytes
required version 2 bytes
general-purpose bit flag 2 bytes
compression method 2 bytes (8=DEFLATE; 0=UNCOMPRESSED)
last modified file time 2 bytes
last modified file date 2 bytes
crc-32 4 bytes
Last updated 6/6/2012
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