Free jars software for linux

ProGuard is a free Java class file shrinker, optimizer, and obfuscator. ProGuard project can detect and remove unused classes, fields, methods, and attributes. It can then optimize bytecode and remove unused instructions.
Finally, it can rename the remaining classes, fields, and methods using short meaningless names. The resulting jars are smaller and harder to reverse-engineer.
More compact jar files also means smaller storage requirements, faster transfer of applications across networks, faster loading, and smaller memory footprints.
ProGuards main advantage compared to other Java obfuscators is probably its compact template-based configuration. A few intuitive command line options or a simple configuration file are usually sufficient. For instance, the following configuration option preserves all applets in a jar:
-keep public class * extends java.applet.Applet
The user manual explains all available options and shows more examples of this powerful configuration style.
ProGuard is fast. It only takes seconds to process programs and libraries of several megabytes. The results section presents actual figures for a number of applications.
ProGuard is a command-line tool with an optional graphical user interface. It also comes with plugins for Ant and for the J2ME Wireless Toolkit.
ProGuard is a Java class file shrinker, optimizer, and obfuscator. The shrinking step detects and removes unused classes, fields, methods, and attributes. The optimization step analyzes and optimizes the bytecode of the methods. The obfuscation step renames the remaining classes, fields, and methods using short meaningless names. The resulting jars are smaller and harder to reverse-engineer.
ProGuard can also be used to list unused fields and methods in an application, and to print out the internal structure of class files.
ProGuard typically reads the input jars (or wars, ears, zips, or directories). It then shrinks, optimizes, and obfuscates them. It then writes the results to one or more output jars (or wars, ears, zips, or directories). The input jars can optionally contain resource files. ProGuard copies all non-class resource files from the input jars to the output jars. Their names and contents remain unchanged.
ProGuard requires the library jars (or wars, ears, zips, or directories) of the input jars to be specified. It can then reconstruct class hierarchies and other class dependencies, which are necessary for proper shrinking, optimization, and obfuscation. The library jars themselves always remain unchanged. You should still put them in the class path of your final application.
In order to determine which code has to be preserved and which code can be discarded or obfuscated, you have to specify one or more entry points to your code. These entry points are typically classes with main methods, applets, midlets, etc.
- In the shrinking step, ProGuard starts from these seeds and recursively determines which classes and class members are used. All other classes and class members are discarded.
- In the optimization step, ProGuard further optimizes the code. Among other optimizations, classes and methods that are not entry points can be made final, and some methods may be inlined.
- In the obfuscation step, ProGuard renames classes and class members that are not entry points. In this entire process, keeping the entry points ensures that they can still be accessed by their original names.
Any classes or class members of your code that are created or invoked dynamically (that is, by name) have to be specified as entry points too. It is generally impossible to determine these cases automatically, but ProGuard will offer some suggestions if keeping some classes or class members appears necessary. For proper results, you should at least be somewhat familiar with the code that you are processing.
ProGuard does handle Class.forName("SomeClass") and SomeClass.class constructs automatically. The referenced classes are preserved in the shrinking phase, and the string arguments are properly replaced in the obfuscation phase. With variable string arguments, it is generally impossible to determine their possible values (they might be read from a configuration file, for instance).
However, as mentioned, ProGuard will note constructs like "(SomeClass)Class.forName(variable).newInstance()". These might be an indication that the class or interface SomeClass and/or its implementations may need to be preserved. You can then adapt your configuration accordingly.
Whats New in 3.9 Stable Release:
- This release fixes a number of bugs.
- Notably, ".class" constructs compiled in Java 6 are now handled correctly.
- The optimization step now avoids a possible division by 0 and correctly processes local variables with indices larger than 255.
- The documentation and examples have been updated.
Whats New in 4.0 Beta Development Release:
- Added preverifier for Java 6 and Java Micro Edition, with new option -dontpreverify.
- Added new option -target to modify java version of processed class files.
- Made -keep options more orthogonal and flexible, with option modifiers allowshrinking, allowoptimization, and allowobfuscation.
- Added support for configuration by means of annotations.
- Improved shrinking of unused annotations.
- Added check on modification times of input and output, to avoid unnecessary processing, with new option -forceprocessing.
- Added new options -flattenpackagehierarchy and -repackageclasses (replacing -defaultpackage) to control obfuscation of packages names.
- Added new options -adaptresourcefilenames and -adaptresourcefilecontents, with file filters, to update resource files corresponding to obfuscated class names.
- Now respecting naming rule for nested class names (EnclosingClass$InnerClass) in obfuscation step, if InnerClasses attributes or EnclosingMethod attributes are being kept.
- Added new inter-procedural optimizations: method inlining and propagation of constant fields, constant arguments, and constant return values.
- Added optimized local variable allocation.
- Added over 250 new peephole optimizations.
- Improved making classes and class members public or protected.
- Now printing notes on suspiciously unkept classes in parameters of specified methods.
- Now printing notes for class names that dont seem to be fully qualified.
- Added support for uppercase filename extensions.
- Rewritten class file I/O code.
- Updated documentation and examples.

Jar::Signer Perl module ease the process of creating a signed Jar file.

SYNOPSIS

# using FindBin is just a suggestion.
use FindBin qw( $RealBin );
use Jar::Signer;
my $signer = Jar::Signer->new;
# location of the keystore, created if needed.
$signer->keystore("$RealBin/MyKeyStore");
# dname properties of the certificate.
$signer->dname("CN=Mark Southern, O=My Corporation, L=My State, C=USA");
# name for .fingerprint and ..cert files, created if needed.
$signer->alias("$RealBin/MyCert");
# the Jar file that we want to sign.
$signer->jar(shift);
# if signed_jar is undefined then the default is basename.signed.jar where basename is the basename of the Jar file.
$signer->signed_jar(shift);
# create the signed Jar.
$signer->process;

This module, and the script that uses it make it a lot simpler to generate signed Jar files for use in Java applets etc. It steps through all the needed jar, jarsigner and keytool command lines.

Bio::Tools::Run::JavaRunner is a Perl module that can run java programs.

SYNOPSIS

my $runner = Bio::Tools::Run::JavaRunner->new(-jar => $jar);
$runner->run();

This module is probably incomplete. It is intended to be a wrapper for running java programs.