Webstart runs with wrong version of JRE

Question

I have a Java webstart application that requires Java 7+, so the JNLP has this line:

<j2se version="1.7+" href="http://java.sun.com/products/autodl/j2se"/>

This works on various Windows XP & Windows 7 machines (most of them also having Java 6 installed) but on one of them, webstart is launched with Java 6 and fails (wrong version of JRE). I found this post and checked the Java settings and they look fine:

I have also tried changing the JNLP line to this but it still does not work:

<j2se version="1.7+"/>

Any ideas on how to let webstart know that the JRE 1.7 is there?

Config: Windows 7, run as administrator - webstart application launched from IE.

Violent

I don't know much about this but, are you sure it's not something to do with a setting in IE somewhere? I know IE can be a pain in the butt . – Lipson

@PerryMonschau I have no idea - I checked the Internet Options but could not find anything that seemed related. It is not a security issue because the application is launched (but with wrong JRE)... – Violent

Ok, try following the steps in the first or second answer here: #71754 Except replace his 1.5 with 1.7 – Lipson

Be sure to validate the JNLP using JaNeLA as a first step. Many JNLP files are horridly broken, and it is not predictable how the JWS client will interpret them. Then if it still fails, try it with 1.6 unselected (which should not be necessary, but I am curious as to whether it will work). Then check the bug DB and if you find nothing similar, start a new one & see what Oracle has to say on the matter. – Meteorite

@AndrewThompson Actually even with 1.6 unchecked, it still runs with 1.6... weird... – Violent

@AndrewThompson JaNeLa worked fine. I found the issue - posting the answer now (I feel a little stupid). – Violent

@AndrewThompson By the way, I just realised you developed JaNeLa - I get a NPE for one of my JNLP. Let me know if you want to see the file. – Violent

"I get a NPE for one of my JNLP." I don't quite get it. Do you mean that JaNeLA is reporting that error to you about the JNLP, or that your console/log/command line is reporting that JaNeLA itself threw an NPE? – Meteorite

When opening the JNLP in JaNeLa, I get a dialog titled "Problem with URL" and the text is "java.lang.NullPointerException". – Violent

Answer 1

I found the problem. I had Java 6 32bits & 64bits installed, but Java 7 only had the 64bits version installed. And I was launching the webstart link from Internet Explorer 32 bits, which I suppose cannot use a 64 bits version of JRE.

Launching the webstart from IE 64 bits worked fine.

Thanks for your comments, I figured the problem out while doing one of the manipulations you recommended.

Violent

+1 I was bashing my head against the wall with this problem and this answer is absolutely correct. – Willie

Answer 2

I had a similar problem with Java 6 being used to launch JNLPs rather than Java 7 (I have both installed), even though my JAVA_HOME, PATH and Java Control Panel settings were all set to 7. Java 7 would be used when launching from a web page, but from a desktop shortcut, Java 6 was being used and so be unable to launch the app since it requires 7.

Turns out that there are java, javaw and javaws executables present in C:\Windows\SysWOW64 and this is what the generated shortcut points to. So I overwrote those EXEs with the ones from C:\Program Files\Java\jre7\bin.

Perhaps a reinstallation of JRE 7 would also have fixed this but I just went for this quick fix.

Namecalling

+1 for a good result. I've tried both of the solutions on this page and am still struggling with the issue on Windows 10 for one of my users. – Slop