4 GB JAR bypass

Question

I am making a standalone database program that includes many images - enough to make the jar file more than 4 GB, which Netbeans tells me is not allowed.

I would like to know what could be the best way to get my files under this limit, and how to program in Java image access methods. Currently, the image folder is 4.66 GB, and in future updates it will be enlarged (possibly several MB).

What do you suggest, Stackoverflow?

Answer 1

You can create several cans. Why should it be one bank?

Also, starting with Java 1.7.0 build 55 Java supports jars and zip files larger than 4 GB, see this post:

ZIP64, Format for> 4G Zipfile, now supported

You can also compress images, use a different format that compresses them to a smaller size, so they will be less than 4 GB; consider lossy compression such as JPEG. If they are already compressed to a maximum, you can reduce their size (for example, 500x250 pixels instead of 1000x500).

Edit:

Quoting the javadoc form java.util.zip package :

The implementation may optionally support ZIP64 (tm) extensions defined in the PKWARE ZIP file format specification. ZIP64 (tm) extensions are used to overcome the size limitations of the original ZIP format.

So he looks at the java implementation, whether it supports Zip64, this is not a specification requirement. The first link assumes that OpenJDK supports it.

Also, Googleing is a bit like Oracle JDKs, supporting it after the mentioned version (1.7.0 b55). Netbeans may prohibit the creation of banks larger than 4 GB if it is an old version or because it wants to maintain compatibility with older JVMs.

How to find out if your Java supports?

In case of Oracle JRE / JDK: find the rt.jar (runtime.jar) JRE / JDK file. Open it (this is a zip file) and go to the java/util/zip folder. If it has a ZipConstants64.class file, then it supports Zip64.

From Java code: try to acquire a Class object for the specified class. If this succeeds, your Oracle JRE / JDK supports it:

 System.out.println("Java version: " + System.getProperty("java.version")); System.out.println("Java vendor: " + System.getProperty("java.vendor")); try { Class.forName("java.util.zip.ZipConstants64"); System.out.println("Your Java supports Zip64 :)"); } catch (ClassNotFoundException e) { System.out.println("Your Java doesn't support Zip64 :("); } 

Conclusion:

 Java version: 1.8.0_20 Java vendor: Oracle Corporation Your Java supports Zip64 :)