How to do that? In fact we have 1.8 outside, 1.7 inside However, DOMjudge chroot is fetching only 1.7. Can we change it?

________________________________________ From: Tobias Werth werth@cs.fau.de Sent: Wednesday, December 16, 2015 5:16 PM To: Br. Anand Shenoi; domjudge-devel@domjudge.org; Jaap Eldering; Thijs Kinkhorst Subject: Re: Switching from Java 1.7 to 1.8 - UnsupportedClassVersionError

Hi,

On 12/16/15 12:45, Br. Anand Shenoi wrote:

Here is an error from a java program:

Program error output

Exception in thread "main" java.lang.UnsupportedClassVersionError: SimilarStrings : Unsupported major.minor version 52.0 at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClass(ClassLoader.java:800) at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142) at java.net.URLClassLoader.defineClass(URLClassLoader.java:449) at java.net.URLClassLoader.access$100(URLClassLoader.java:71) at java.net.URLClassLoader$1.run(URLClassLoader.java:361) at java.net.URLClassLoader$1.run(URLClassLoader.java:355) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:354) at java.lang.ClassLoader.loadClass(ClassLoader.java:425) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308) at java.lang.ClassLoader.loadClass(ClassLoader.java:358) at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:482)

The JDK in Judgenode is 1.8 whereas chroot in domjudge is fetching only 1.7. Any way to resolve this error?

Install the same Java version inside and outside of the chroot. So, either downgrade javac outside to java7 or update it inside to java8.

Cheers, Tobi

Hi Anand,

openjdk-8 is not in Debian Jessie, the Debian version that is used to build the chroot. It is available in jessie-backports, so you could manually enter the chroot and then add that archive to the apt sources and install it.

See the dj_make_chroot script for how to enter the chroot environment manually (you probably need to mount proc and dev and copy /etc/resolv.conf to make apt work properly inside it) and see: http://backports.debian.org/Instructions/

Jaap

On 16-12-15 12:43, Br. Anand Shenoi wrote:

Hi all,

We tried editing chroot file. There is a parameter called INSTALLDEBS="openjdk-8-jre-headless". But it is not picking the jre8 and generated error.

Please resolve this issue.

---

From: DOMjudge-devel domjudge-devel-bounces@domjudge.org on behalf of Br. Anand Shenoi anandam@outlook.com Sent: Wednesday, December 16, 2015 5:18 PM To: Tobias Werth; domjudge-devel@domjudge.org; Jaap Eldering; Thijs Kinkhorst Subject: Re: Switching from Java 1.7 to 1.8 - UnsupportedClassVersionError

How to do that? In fact we have 1.8 outside, 1.7 inside However, DOMjudge chroot is fetching only 1.7. Can we change it?

---

From: Tobias Werth werth@cs.fau.de Sent: Wednesday, December 16, 2015 5:16 PM To: Br. Anand Shenoi; domjudge-devel@domjudge.org; Jaap Eldering; Thijs Kinkhorst Subject: Re: Switching from Java 1.7 to 1.8 - UnsupportedClassVersionError

Hi,

On 12/16/15 12:45, Br. Anand Shenoi wrote:

...

Here is an error from a java program:

Program error output

Exception in thread "main" java.lang.UnsupportedClassVersionError: SimilarStrings : Unsupported major.minor version 52.0 at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClass(ClassLoader.java:800) at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142) at java.net.URLClassLoader.defineClass(URLClassLoader.java:449) at java.net.URLClassLoader.access$100(URLClassLoader.java:71) at java.net.URLClassLoader$1.run(URLClassLoader.java:361) at java.net.URLClassLoader$1.run(URLClassLoader.java:355) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:354) at java.lang.ClassLoader.loadClass(ClassLoader.java:425) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308) at java.lang.ClassLoader.loadClass(ClassLoader.java:358) at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:482)

The JDK in Judgenode is 1.8 whereas chroot in domjudge is fetching only 1.7. Any way to resolve this error?

Install the same Java version inside and outside of the chroot. So, either downgrade javac outside to java7 or update it inside to java8.

Cheers, Tobi

---

DOMjudge-devel mailing list DOMjudge-devel@domjudge.org https://www.domjudge.org/mailman/listinfo/domjudge-devel _______________________________________________ DOMjudge-devel mailing list DOMjudge-devel@domjudge.org https://www.domjudge.org/mailman/listinfo/domjudge-devel

Hi Jaap,

It works!!

________________________________________ From: DOMjudge-devel domjudge-devel-bounces@domjudge.org on behalf of Jaap Eldering jaap@jaapeldering.nl Sent: Wednesday, December 16, 2015 9:11 PM To: domjudge-devel@domjudge.org Subject: Re: Switching from Java 1.7 to 1.8 - UnsupportedClassVersionError

Hi Anand,

openjdk-8 is not in Debian Jessie, the Debian version that is used to build the chroot. It is available in jessie-backports, so you could manually enter the chroot and then add that archive to the apt sources and install it.

See the dj_make_chroot script for how to enter the chroot environment manually (you probably need to mount proc and dev and copy /etc/resolv.conf to make apt work properly inside it) and see: http://backports.debian.org/Instructions/

Jaap

On 16-12-15 12:43, Br. Anand Shenoi wrote:

Hi all,

We tried editing chroot file. There is a parameter called INSTALLDEBS="openjdk-8-jre-headless". But it is not picking the jre8 and generated error.

Please resolve this issue.

---

From: DOMjudge-devel domjudge-devel-bounces@domjudge.org on behalf of Br. Anand Shenoi anandam@outlook.com Sent: Wednesday, December 16, 2015 5:18 PM To: Tobias Werth; domjudge-devel@domjudge.org; Jaap Eldering; Thijs Kinkhorst Subject: Re: Switching from Java 1.7 to 1.8 - UnsupportedClassVersionError

How to do that? In fact we have 1.8 outside, 1.7 inside However, DOMjudge chroot is fetching only 1.7. Can we change it?

---

From: Tobias Werth werth@cs.fau.de Sent: Wednesday, December 16, 2015 5:16 PM To: Br. Anand Shenoi; domjudge-devel@domjudge.org; Jaap Eldering; Thijs Kinkhorst Subject: Re: Switching from Java 1.7 to 1.8 - UnsupportedClassVersionError

Hi,

On 12/16/15 12:45, Br. Anand Shenoi wrote:

...

Here is an error from a java program:

Program error output

Exception in thread "main" java.lang.UnsupportedClassVersionError: SimilarStrings : Unsupported major.minor version 52.0 at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClass(ClassLoader.java:800) at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142) at java.net.URLClassLoader.defineClass(URLClassLoader.java:449) at java.net.URLClassLoader.access$100(URLClassLoader.java:71) at java.net.URLClassLoader$1.run(URLClassLoader.java:361) at java.net.URLClassLoader$1.run(URLClassLoader.java:355) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:354) at java.lang.ClassLoader.loadClass(ClassLoader.java:425) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308) at java.lang.ClassLoader.loadClass(ClassLoader.java:358) at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:482)

The JDK in Judgenode is 1.8 whereas chroot in domjudge is fetching only 1.7. Any way to resolve this error?

Install the same Java version inside and outside of the chroot. So, either downgrade javac outside to java7 or update it inside to java8.

Cheers, Tobi

---

DOMjudge-devel mailing list DOMjudge-devel@domjudge.org https://www.domjudge.org/mailman/listinfo/domjudge-devel _______________________________________________ DOMjudge-devel mailing list DOMjudge-devel@domjudge.org https://www.domjudge.org/mailman/listinfo/domjudge-devel

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