JRuby on Web Start

From JRubyWiki

Contents 1 Deploying JRuby applications with Java Web Start 1.1 Known Issues 1.2 Samples 1.2.1 Getting jirb.jnlp sample to work in Java 1.5 1.2.2 New jnlp samples dir 1.3 JAR Signing 1.4 Disabling the Security Manager

Deploying JRuby applications with Java Web Start

Known Issues

Open JIRA Issues matching "Web Start or jnlp or javaws"

Samples

The samples directory distributed with JRuby (as of Dec 29 2007 this sample is only on the subversion trunk version of JRuby) has an example jnlp, jirb.jnlp which will start the JRuby Swing IRB console as a Java Web Start application.

Getting jirb.jnlp sample to work in Java 1.5

The jirb.jnlp needs to be modified to work on Java 1.5 because of the use of ".." in the codebase attribute which only works in Java 1.6. 1. make a symbolic link to the directory $JRUBY_HOME/lib in the samples directory (or make a copy of the lib directory).

 $ cd $JRUBY_HOME/samples
 $ ln -s ../lib

2, change the codebase attribute in the jnlp element to use a reference to the local directory

 <jnlp spec="1.0+" codebase="file:.">

3. start the jnlp using javaws from the command line

 $ javaws jirb.jnlp

New jnlp samples dir

This Jira issue:

• JRUBY-2040: new samples/jnlp dir: includes both unsigned and signed examples that work in Java 1.5 and 1.6

includes an attachment which when extracted in samples/ adds s both unsigned and signed examples that work in Java 1.5 and 1.6. It is projected to be included in JRUBY 1.1 RC2.

JAR Signing

If you're getting an java.securityAccessControlException with the message access denied (java.lang.RuntimePermission accessDeclaredMembers) on startup or when running your JRuby application, then you'll need to sign your jar. The whole process is described here, under "Signing JAR Files with a Test Certificate". You basically have to perform the following steps:

keytool -genkey -keystore myKeystore -alias myself
keytool -selfcert -alias myself -keystore myKeystore

You also need to include to following lines in your jnlp-file:

<security> 
  <all-permissions/> 
</security>

And whenever you modify the jar, you need to do an

jarsigner -keystore myKeystore test.jar myself

to update the signature.

Disabling the Security Manager

If you have a signed jar and the startup fails because of an java.lang.reflect.ReflectPermission or you continue to have access denied (java.lang.RuntimePermission accessDeclaredMembers) errors, you can just disable the security manager:

JRuby:

java.lang.System.setSecurityManager(nil)

Java:

System.setSecurityManager(null);

Disclaimer: I'm not an expert on Java Security, so I don't know if disabling the Security Manager has unintended sideeffects. Mstocker 10:49, 30 December 2007 (PST)

See: JRUBY-1821 and JRUBY-1782.