Minecraft not starting under JRockIt VM

Question

I have been trying to run minecraft under 64-bit JRockIt, hoping to get better performance (Will I? It works very well for server applications.)

I use the command:

"C:\Program Files\Java\jre6\bin\java" -Xms512m -Xmx4096m -cp "%APPDATA%\.minecraft\bin\*" -Djava.library.path="%APPDATA%\.minecraft\bin\natives" net.minecraft.client.Minecraft

However JRockit probably considers the "." in the any name as a package delimiter

C:\Users\Midhat\Desktop>java -Xms512m -Xmx4096m -cp "C:\Users\Midhat\AppData\Roa
ming\.minecraft\bin\*" -Djava.library.path="C:\Users\Midhat\AppData\Roaming\.min
ecraft\bin\natives" net.minecraft.client.Minecraft 
Exception in thread "Main Thread" java.lang.NoClassDefFoundError: C:\Users\Midha
t\AppData\Roaming\/minecraft\bin\lwjgl/jar
Caused by: java.lang.ClassNotFoundException: C:\Users\Midhat\AppData\Roaming\.mi
necraft\bin\lwjgl.jar
        at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
        at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
Could not find the main class: C:\Users\Midhat\AppData\Roaming\.minecraft\bin\lw
jgl.jar.  Program will exit.

Is there any way I can use JRockIt to run Minecraft? Could this be a JRockIt bug?

Answer 1

If this were Unix, then this part would be wrong; I'm not sure whether the same applies to Windows. But it seems likely, since the error is a pathname where it expects a class name.

-cp "C:\Users\Midhat\AppData\Roaming\.minecraft\bin\*"

This is w wrong because the * expands to multiple arguments, whereas -cp takes only one argument after it (it expects a series of pathnames separated by semicolons on Windows).

To handle this, you need to explicitly give the paths to the jars (replace the ... with the rest of the pathname you had; I'm just condensing the example) as a single argument.

-cp "C:\...\jinput.jar;C:\...\lwjgl_util.jar;C:\...\lwjgl.jar;C:\...\minecraft.jar"

Answer 2

Try not specifying the classname - "net.minecraft.client.Minecraft"; you may not necessarily need to specify the classname. OpenJDK seems to get on fine without it.