From Fedora Project Wiki

https://fedoraproject.org/wiki/Java/Troubleshooting

OpenJDK package name on Fedora is java-1.?.0-openjdk.


Java Consoles

There are at least 2 consoles:

  • OpenJDK 8
    • Monitoring ...
    • Policy ...
  • IcedTea (deprecated ??)
    • Monitoring
    • Policy ...

shared library paths

OpenJDK's java.library.path, shared library paths for i386 are: 

/usr/lib
/usr/lib/jvm/java-1.?.0-openjdk-1.?.0.0.x86_64/jre/lib/

and for x86_64: 

/usr/lib64
/usr/lib/jvm/java-1.?.0-openjdk-1.?.0.0.x86_64/jre/lib/amd64/


Java subsystem debugging

Preparations

For all Java subsystem debugging, installing the symbols package java-1.8.0-openjdk-debuginfo is essential. All debuginfo sub-packages reside in own repository which needs to be enabled for installation at least. An example yum command: 

# dnf install --enablerepo=fedora-debuginfo -y java-1.8.0-openjdk-debuginfo

Applets ??

Applets are deprecated, no ???

Console has moved to icedTea itself (requires icedtea-web package). Activating the console can be done with gui-tool: 

 Program menu --> Settings --> IcedTea Web Control Panel


Console can for example list detailed information about the environment which can be useful for bug reporting: 

System Properties:

http.agent: Java(tm) 2 SDK, Standard Edition v1.6.0_0
package.restrict.definition.java: true
java.version.applet: true
java.runtime.name: OpenJDK Runtime Environment
sun.boot.library.path: /usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0.x86_64/jre/lib/amd64
java.vm.version: 14.0-b16
browser: sun.applet.AppletViewer
java.vendor.applet: true
java.vm.vendor: Sun Microsystems Inc.
java.vendor.url: http://java.sun.com/
path.separator: :
java.vm.name: OpenJDK 64-Bit Server VM
file.encoding.pkg: sun.io
file.separator.applet: true
user.country: US
sun.java.launcher: SUN_STANDARD
sun.os.patch.level: unknown
os.version.applet: true
java.vm.specification.name: Java Virtual Machine Specification
user.dir: /home/tuju/Documents
java.runtime.version: 1.6.0_0-b16
java.awt.graphicsenv: sun.awt.X11GraphicsEnvironment
java.endorsed.dirs: /usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0.x86_64/jre/lib/endorsed
os.arch: amd64
browser.version: 1.06
javax.accessibility.assistive_technologies: org.GNOME.Accessibility.JavaBridge
line.separator: 

java.io.tmpdir: /tmp
java.vm.specification.vendor: Sun Microsystems Inc.
os.name: Linux
java.class.version.applet: true
sun.jnu.encoding: UTF-8
java.library.path: /usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0.x86_64/jre/lib/amd64/server:/usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0.x86_64/jre/lib/amd64:/usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0.x86_64/jre/../lib/amd64:/usr/lib64/firefox-3.5.5:/usr/lib64/firefox-3.5.5/plugins:/usr/lib64/firefox-3.5.5:/usr/java/packages/lib/amd64:/usr/lib64:/lib64:/lib:/usr/lib
java.class.version: 50.0
java.specification.name: Java Platform API Specification
path.separator.applet: true
sun.management.compiler: HotSpot 64-Bit Server Compiler
package.restrict.definition.sun: true
os.arch.applet: true
os.version: 2.6.30.9-96.fc11.x86_64
browser.vendor: Sun Microsystems Inc.
user.home: /home/tuju
user.zoneinfo.dir: /usr/share/javazi
user.timezone: Europe/Tallinn
java.awt.printerjob: sun.print.PSPrinterJob
line.separator.applet: true
java.specification.version: 1.6
file.encoding: UTF-8
java.class.path: .
user.name: tuju
os.name.applet: true
java.vm.specification.version: 1.0
java.home: /usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0.x86_64/jre
sun.arch.data.model: 64
user.language: en
java.specification.vendor: Sun Microsystems Inc.
java.vm.info: mixed mode
java.version: 1.6.0_0
java.ext.dirs: /usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0.x86_64/jre/lib/ext:/usr/java/packages/lib/ext
sun.boot.class.path: /usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0.x86_64/jre/lib/resources.jar:/usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0.x86_64/jre/lib/rt.jar:/usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0.x86_64/jre/lib/sunrsasign.jar:/usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0.x86_64/jre/lib/jsse.jar:/usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0.x86_64/jre/lib/jce.jar:/usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0.x86_64/jre/lib/charsets.jar:/usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0.x86_64/jre/lib/rhino.jar:/usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0.x86_64/jre/classes
java.vendor: Sun Microsystems Inc.
file.separator: /
java.vendor.url.bug: http://java.sun.com/cgi-bin/bugreport.cgi
sun.io.unicode.encoding: UnicodeLittle
sun.cpu.endian: little
java.vendor.url.applet: true
sun.cpu.isalist:


Test URLs

Fedora's JRE in browser environment can be tested using the following test pages:

Note that those pages itself are sad examples of compliance of specifications: buggy or buggier - if you know any better pages, change them here.

See Also

References

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