General
At this section we want to answer some of the mostly asked questions about general jBEAM usage.
What are the jBEAM system requirements?
CPU: Any modern CPU, the faster the better.
RAM: 1GB minimum, at least 8GB recommended.
Hard Disk: 1GB minimum for program files, at least 4G recommended for temporary files and more.
Supported Operating Systems
Windows, Windows 10 recommended
Linux
Mac OS-X
64bit, even 32bit possible
Java Runtime Environment: jBEAM is Java based and comes with a bundled OpenJDK.
jBEAM does not start after updating Java version.
This case only affects customers who do not use our bundled Java, but use their own installation to start jBEAM.
Symptom: Depending on how jBEAM is started, the following error messages appear:
Error: An unexpected error occurred while trying to open file jBEAM.jar
-- or --
Error: Could not find or load main class com.AMS.jBEAM_Extern.jBMain
Reason: Starting with version Java SE 8u381 b32 Oracle introduced a new system property, jdk.jar.maxSignatureFileSize, for setting a maximum size of signature files. And the default setting (8MB) is too small for jBEAM. This change affects equally, the other Java versions, such as Java 11 and so on.
Because there are varous ways to start jBEAM, we will only describe the two most common ones here. If your way of starting jBEAM is not listed here, contact our jBEAM service desk.
In Java 8u401, this value was increased again to a sufficient value (16MB). So that the start of jBEAM is possible again without this parameter. (for more information and versions for Java 11 and higher, see link). https://bugs.openjdk.org/browse/JDK-8313215
Solution for start_jBEAM.bat
We need to insert this new parameter into your existing start_jBEAM.bat file:
Find your jBEAM installation folder (i.e. C:\Program Files\jBEAM-Lab)
Open the start_jBEAM.bat file with a text editor
Find this characteristic if-else-block:
IF %redirectConsole%==yes ( "%javaExeResolved%" -Ddebug=false -Xmx%maxMemory% -XX:+UseG1GC -XX:+UseStringDeduplication "-XX:ErrorFile=%userprofile%\jbCrash_%%p.log" com.AMS.jBEAM_Extern.jBMain -cp "%CLASSPATH%" %importFileParam% SingleInstance=%singleInstance% %startParameters% 1>"%timeStamp%_system.out.txt" 2>"%timeStamp%_system.err.txt" ) ELSE ( "%javaExeResolved%" -Ddebug=false -Xmx%maxMemory% -XX:+UseG1GC -XX:+UseStringDeduplication "-XX:ErrorFile=%userprofile%\jbCrash_%%p.log" com.AMS.jBEAM_Extern.jBMain -cp "%CLASSPATH%" %importFileParam% SingleInstance=%singleInstance% %startParameters% )
Depending on your jBEAM version and individual configurations, the names may be slightly different, but please stay with yours and only add the new parameter as described in (4).
Add this -Djdk.jar.maxSignatureFileSize=32000000 part as first parameter in both lines, i.e.:
IF %redirectConsole%==yes ( "%javaExeResolved%" -Djdk.jar.maxSignatureFileSize=32000000 -Ddebug=false -Xmx%maxMemory% ... ) ELSE ( "%javaExeResolved%" -Djdk.jar.maxSignatureFileSize=32000000 -Ddebug=false -Xmx%maxMemory% ... )
Solution for jnlp file
If you start jBEAM via Java WebStart technology (jnlp file), proceed as follows:
Find and open your jnlp file with a text editor
In this jnlp file, find this characteristic Quickstart run file block:
Next, find and open this run file with a text editor (the name and location of the quickstart.run may vary)
In this run file, find lines starting with vmarg=… and add this new one:
After saving your changes jBEAM should start as before.
In case of problems, contact our jBEAM service desk.
Where do I find a complete overview about the start parameters of jBEAM?
If you wish to get a complete and up-to-date overview about all possible start parameters of jBEAM including some explanation simple start jBEAM using the ”-help” parameter like:
This will print all available parameters to the console including some advice on how to use them.