Java Issues

Java Issues

 

Java is freely down-loadable, open source software that provides a 'virtual machine' or VM that permits software to run on many different machines and operating systems. For more information on Java, see Wikipedia

Visokio applications are pure Java applications that run 'on top' of a Java virtual machine which runs 'on top' of your machine's operating system. This means that you either must have Java 5 or later installed before you can install Visokio applications, or you must use the Full installer which includes Java 6, also available here.

Java is open-source software that is being continuously improved. Periodically, there is a new release of Java, and known issues in Java emerge which are relevant to installation and performance of Visokio applications.

Java compatibility

If your systems already have a conflicting version of Java installed (such as the Microsoft VM, or Java 1.3.x) you must use the full installer. This creates a private Java VM (PVM) specifically for Visokio applications which will not affect any other part of your system.

The private Java VM, installed in Program Files/Visokio Common/pvm15, must be deployed as well as the main Visokio program folder, for example the Omniscope folder: Program Files/Visokio Omniscope.

Alternatively, it is possible to specify your own Java VM, by creating/editing the installconfig.properties file within the main installation folder. See Centralised Deployment for more information.

Known Java Installation issues

In this section, we summarise known Java installation issues and implications of up-grading to the latest versions of Java. Other known issues with Java that do not affect installation, but can cause a hang with no Omniscope error messages are listed here.

Java permissions and security issues

Java has security settings which may affect the treatment of images. If user settings restrict access to certain packages in particular the sun.awt.image package within Java then certain views can be affected. The following issue has been seen before:

java.security.AccessControlException {class java.security.AccessControlException "access denied (java.lang.RuntimePermission accessClassInPackage.sun.awt.image)"
at java.security.AccessControlContext.checkPermission(Unknown Source)
at java.security.AccessController.checkPermission(Unknown Source)
at java.lang.SecurityManager.checkPermission(Unknown Source)
at java.lang.SecurityManager.checkPackageAccess(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClassInternal(Unknown Source)

It is likely that your security policy is not letting you access to classes in java.awt.image packages.
Access to classes in AWT package, viz., and the java.awt.image packages are required.

In order to fix this problem you need to grant Omniscope users permission by adding the following statement

grant {
permission java.lang.RuntimePermission
"accessClassInPackage.sun.awt.image";
}

to any of the security policy files referred to by statements such as

policy.url.1=file:${java.home}/lib/security/java.policy
policy.url.2=file:${user.home}/.java.policy

in the java security configuration file for your installation. This file should
be located at ${java.home}/lib/security/java.security.

${java.home} refers to where java is installed i.e. "C:\j2sdk1.4.2_14".
${user.home} refers to user home directory which on Windows is "C:\Documents and Settings\<user>" where
<user> refers to the user name. For example use named David, user.home would be "C:\Documents and Settings\David"

Known Java on Vista issues

The Windows Vista operating system is not fully supported in Java versions 1.4, Java 1.5 releases prior to build Java 1.5.0_11 (Java 1.5.0_11 or later supports Vista), or Java 6 original release or 1.6.0_01 (Java 1.6.0_02 or later supports Vista). If you are running a Java version not fully supported on Vista please update to the latest release of Java at http://www.java.com or use the PVM version bundled with our applications (Java 1.5.0_11).

International fonts

Some fonts can crash earlier versions of Java and this has been fixed in latest releases of Java. Visokio applications have been modified to minimise the impact of this rare problem in the event you are running older versions of Java.

Java Daylight Savings Time (DST) Compliance

Omniscope, DataPlayer Studio and FeatureFinder are Java applications so their compliance with DST (as recently updated) depends on the Java VM used.

http://java.sun.com/developer/technicalArticles/Intl/USDST/ provides details on Java version DST status.

Our products are available both with and without a bundled private Java VM. The current bundled installers of Omniscope 2.2 and FeatureFinder 1.3 available on our website all use Java 1.5.0_11 which is DST compliant.

Other bundled installers available on our website (such as FeatureFinder 1.2, and Omniscope installers built before Feb 26th 2007) may not be DST compliant. If DST compliance is critical and you cannot upgrade to newer product versions, you must use the non-bundled installer.

If you use a non-bundled installer, it is up to you to ensure the system Java VM is compliant.

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