SYNOPSIS
--------
NullPointerException while launching a Web Start application on a non-Oracle JRE via the Oracle launcher
 
OPERATING SYSTEM
----------------
Windows
 
FULL JDK VERSION
----------------
5.0 onwards
 
DESCRIPTION from LICENSEE
-------------------------
The problem occurs when using the Oracle system JRE to launch a Web Start application on a JRE from a different vendor. Specifically, a JRE that does not use the SUN security provider.

In this scenario the application will fail to launch due to the following NullPointerException:

java.lang.NullPointerException
        at com.sun.deploy.services.WPlatformService.getSecureRandom(Unknown Source)
        at com.sun.deploy.cache.Cache.getSecureRandom(Unknown Source)
        at com.sun.deploy.cache.Cache.getRandom(Unknown Source)
        at com.sun.deploy.cache.Cache$19.run(Unknown Source)
        at java.security.AccessController.doPrivileged(AccessController.java:251)
        at com.sun.deploy.cache.Cache.generateCacheFileName(Unknown Source)
        at com.sun.deploy.cache.Cache.createNewCacheEntry(Unknown Source)
        at com.sun.deploy.cache.Cache.createOrUpdateCacheEntry(Unknown Source)
        at com.sun.javaws.LaunchDownload.updateLaunchDescInCache(Unknown Source)
        at com.sun.javaws.LaunchDownload.updateLaunchDescInCache(Unknown Source)
        at com.sun.javaws.Launcher.updateFinalLaunchDesc(Unknown Source)
        at com.sun.javaws.Launcher.prepareToLaunch(Unknown Source)
        at com.sun.javaws.Launcher.prepareToLaunch(Unknown Source)
        at com.sun.javaws.Launcher.launch(Unknown Source)
        at com.sun.javaws.Main.launchApp(Unknown Source)
        at com.sun.javaws.Main.continueInSecureThread(Unknown Source)
        at com.sun.javaws.Main$1.run(Unknown Source)
        at java.lang.Thread.run(Thread.java:736)


REPRODUCTION INSTRUCTIONS
-------------------------
The issue can be recreated using any simple Web Start application. All that matters is that the application is launched using the Oracle system JRE's deploy code, but targeted to run on a JRE from a different vendor that does not ship with the SUN security provider (e.g. the XYZ JRE).

This scenario can be created by installing the Oracle JRE, and adding the non-Oracle JRE in Java Control Panel -> Java -> View. The Oracle JRE should then be disabled using the same interface to ensure that applications will run on the non-Oracle JRE.

Once this configuration is in place, the Oracle JRE's Web Start launcher code will be used (i.e. downloading of the application jars), but the actual application will be executed on the non-Oracle JRE.

The result, as discussed above, is a NullPointerException whenever you try to run a Web Start application.


SUGGESTED FIX from LICENSEE
---------------------------
The problem is caused by the fact that the following method assumes that the SUN provider will always be present:

com/sun/deploy/services/WPlatformService.getSecureRandom()

The fix is to add a null check, so that if the call Security.getProvider("SUN") returns null, we just continue with the default provider. These diffs are based on 7u5:

--- WPlatformService-old.java 2012-08-07 10:36:53.508359400 +0100
+++ WPlatformService-new.java 2012-08-07 10:42:47.463604500 +0100
@@ -143,9 +143,12 @@
         // Obtain Sun service provider
         Provider provider = Security.getProvider("SUN");

- // Reset secure random support
- provider.put("SecureRandom.SHA1PRNG", "com.sun.deploy.security.WSecureRandom");
-
+ // If SUN provider is not present, fallback to the default provider
+ if (provider != null) {
+ // Reset secure random support
+ provider.put("SecureRandom.SHA1PRNG", "com.sun.deploy.security.WSecureRandom");
+ }
+
         return new SecureRandom();
     }