Develop Reference

Generate SPSS File using PL/SQL

Problem:
I am looking for a way to generate a SPSS file using PL/ SQL. Currently, I am able to generate a .csv file with roughly 300-400 columns. I have tried to google and didn't have any luck in finding a way to generate SPSS file using PL/SQL.
Expected Solution:
Either generate a SPSS file directly OR use some kind of java class like one this program SPSS Writer uses to convert the .csv file into SPSS. My understanding is that we would need to provide the metadata file in order to convert the csv file into SPSS.
Any suggestions would be much appreciated.

If you are trying to generate a sav file without SPSS you can write a program using the SPSS io modules available free via the SPSS community website.

Update data documents for JWS deployed app

I have a swing application that uses many data files, these data files will change time to time. How can I load these data files on client's machine? Is there any way to create a folder like structure and run a batch file or so? Any help is appreciated.

There are several ways to do this:
Assume you want to ship your application with the datafiles, you may embed them as a zip/jar in your application-jar-file.
Extract the embedded zip to a temporary local file and use ZipFileSystemProvider to extract the content to some place on the disc.
Here is an example how to extract some content from zip/jar-file embedded in a .jar-file downloaded by JWS.
Same as 1, but skip the zip stuff and instead provide a list of all the resources you want to extract
One other way is to create the files pragmatically using either java.nio.file (java 7+) or java.io.File

Is it possible to open a TrueZIP archive from a stream?

Using TrueZIP, is there a way to open and modify an existing ZIP file from a stream (it may of course be outputted using another stream)?
I have code for modifying a ZIP that works perfectly as long as I work on an existing real ZIP file on the file system but I have a requirement that all temporary files need to be encrypted while stored on disk. In most part of our application this is easy to achieve (using CipherOutputStream and CipherInputStream) but I have one function that uses TrueZIP to update an existing ZIP file. This part obviously fails if the file is encrypted.
The ZIP files will be consumed by proprietary applications that do not support encryption so using the encryption that is part of the ZIP specification isn't possible.
The reason we are using TrueZIP is that we need the support for Zip64 (which I know is included in Java 7 but we cannot switch right now).

No, an archive file must be stored in accessible file system to use it with TrueZIP. But you have a number of other options:
TrueZIP uses instances of the IOPoolService interface to manage temporary files. You could provide your own implementation which encrypts all temporary files or maybe even just stores them on the heap (if they are small). Have a look at the TrueZIP Driver FILE to see the reference implementation.
You could use the ParanoidZipRaesDriver to use RAES encrypted ZIP files. This driver ensures that no unencrypted temporary files are used by limiting the number of concurrent threads for writing an archive file to one.
You could use the standard ZIP drivers with FsOutputOption.ENCRYPT to switch on WinZip AES encryption. To ensure that no unencrypted temporary files are used, you could then override the ZipDriver.newOutputSocket method just like the ParanoidZipRaesDriver does.

Using zip file without extracting in java

I'm facing a problem that, we have a .zip file that contains some text files. Now I'm using java to access that files. If it is not in the .zip file I can read and print on my console easily using FileInputStream.
But how to read a file from .zip file? I use J2SE only..

You should try a ZipInputStream. The interface is a little obtuse, but you can use getNextEntry() to iterate through the items in the .zip file.
As a side note, the Java class-loader does exactly this to load classes from .jar files without extracting them first.

Everything you need is in ZipFile: https://docs.oracle.com/javase/7/docs/api/java/util/zip/ZipFile.html. Google for examples on the web, and if you have specific problems then come back to SO for help.
(The link will eventually break; when it does simply websearch java zipfile.)

Help in creating Zip files from .Net and reading them from Java

I'm trying to create a Zip file from .Net that can be read from Java code.
I've used SharpZipLib to create the Zip file but also if the file generated is valid according to the CheckZip function of the #ZipLib library and can be successfully uncompressed via WinZip or WinRar I always get an error when trying to uncompress it using the Java.Utils.Zip class in Java.
Problem seems to be in the wrong header written by SharpZipLib, I've also posted a question on the SharpDevelop forum but with no results (see http://community.sharpdevelop.net/forums/t/8272.aspx for info) but with no result.
Has someone a code sample of compressing a Zip file with .Net and de-compressing it with the Java.Utils.Zip class?
Regards
Massimo

I have used DotNetZip library and it seems to work properly. Typical code:
using (ZipFile zipFile = new ZipFile())
{
zipFile.AddDirectory(sourceFolderPath);
zipFile.Save(archiveFolderName);
}

I had the same problem creating zips with SharpZipLib (latest version) and extracting with java.utils.zip.
Here is what fixed the problem for me. I had to force the exclusion of the zip64 usage:
ZipOutputStream s = new ZipOutputStream(File.Create(someZipFileName))
s.UseZip64 = UseZip64.Off;

Can't help with SharpZipLib, but you can try to create zip file using ZipPackage class System.IO.Packaging without using 3rd part libraries (requires .NET 3+).

To judge whether it's really a conformant ZIP file, see PKZIP's .ZIP File Format Specification.
For what it's worth I have had no trouble using SharpZipLib to create ZIPs on a Windows Mobile device and open them with WinZip or Windows XP's built-in Compressed Folders feature, and also no trouble producing ZIPs on the desktop with SharpZipLib and processing them with my own ZIP extraction utility (basically a wrapper around zlib) on the mobile device.

You don't wanna use the ZipPackage class in .NET - it isn't quite a standard zip model. Well it is, but it presumes a particular structure in the file, with a manifest with a well-known name, and so on. ZipPackage seems to have been optimized for Office docs and XPS docs.
A third-party library, like http://www.codeplex.com/DotNetZip, is probably a better bet if you are doing general-purpose ZIP files and want good interoperability.
DotNetZip builds files that are very interoperable with just about everything, including Java's java.utils.zip. But be careful using features that Java does not support, like ZIP64 or Unicode. ZIP64 is useful only for very large archives, which Java does not support well at this time, I think. Java supports Unicode in a particular way, so if you produce a Unicode-based ZIP file with DotNetZip, you just have to follow a few rules and it will work fine.

I had a similar problem with unzipping SharpZipLib-zipped files on Linux. I think I solved it (well I works on Linux and Mac now, I tested it), check out my blog post: http://igorbrejc.net/development/c/sharpziplib-making-it-work-for-linuxmac