#352 OpenJDK and DrJava
I'm just wondering if there is any plan to update DrJava to support OpenJDK and OpenJRE given that Oracle is changing their licencing. The IT department for my school board says we can no longer using OracleJDK/JRE due to these licencing changes.
I have been teaching Java using DrJava for some time now and would like to continue to do so as I really prefer its simple interface for beginners.
I have attempted to use open versions of JDK and JRE with DrJava (on both 64bit Win7 and Win10) and so far with only limited success. I uninstalled all Oracle JDK and JRE from system and then installed the OpenJDK that inlcudes the OpenJRE. Specfically, I installed the version 8 OpenJDK. However DrJava won't open and simply provides an error saying it needs at least JRE1.5 installed and then popping open java.com in the browser. I have tried changing system variable paths but nothing seems to allow DrJava to find the OpenJRE.
If I install Oracle JRE from java.com then DrJava will start working. Interestingly when it does finally run like that, the compiler tab is reporting that it is using OpenJDK7-7.5 even though I have installed OpenJDK8. Regardless, so far all testsin DrJava with the OpenJDK8 + OracleJRE seem to working fine.
It would be good to have one easy solution to install and use DrJava this coming september not just at school but to be able to provide simple directions to my students on installing and using DrJava for home use.
Hope to hear back soon.
DrJava should run without any change using OpenJDK8. I just tested it my
Linux laptop (running Ubuntu 18.04) using the OpenJDK8 distributed from the
Ubuntu 18.04 repository. I have multiple JDKs installed on that machine so
I have to identify which "java" command that I want to run. Each JDK
distribution (a file tree) includes a bin directory containing java and
javac. DrJava found the Java 8 compilers for both Oracle JDK8 and
OpenJDK8. I selected the latter and successfully compiled and tested a
large programming project that I assign in one of my classes at Rice. I
could not detect any differences in behavior running DrJava using OpenJDK8
and Oracle JDK8. Tomorrow I will try the same experiment on my Windows 10
laptop on which I currently do not have OpenJDK8 installed.
When I run DrJava on my Linux laptop I use the terminal command line:
java -jar drjava.jar
where "java" resolves (using the shell search PATH) to the OpenJDK8 java
application and "drjava.jar" is the jar file for DrJava. In Windows 10,
if you rely on double-clicking the drjava.jar icon, I cannot predict what
happens since it depends on what is stored in your registry and each JDK
installation mucks with the relevant registry entries. (I am not a Windows
10 wizard.) You can use the Windows 10 command line in same way a the
Linux command line but it can be awkward. Software developers love Linux
so much that Windows 10 includes an embedded Linux implementation called
WSL (which can be configured to be any of several LInux distributions)
which almost works. Unfortunately, some fairly common Linux file names are
illegal in the Windows 10 NTFS file system (but legal in the Linux
implementation of NTFS!) so some Linux applications break. Ugh.
I will post an update tomorrow after I try OpenJDK8 on Windows 10.
On Fri, Jul 5, 2019 at 5:25 PM Sal Iacono icons@users.sourceforge.net
wrote:
Related
Support Requests: #352
Thanks for the quick response Robert.
I'm glad to hear that it should work. I did try both the jar version and
the exe version by double click on file but I didn't think to try launching
the jar from the command line. I will see if that makes a difference.
Like I said before it seems like the program checks for the jre at launch
and for some reason it doesn't find the open version. I opened a command
prompt and entered 'java -version' to see what version windows sees and it
reported back the open version so I'm not sure of the issue. But when I
then install Oracle JRE drjava then runs fine using the openjdk.
Thanks again and I look forward to hearing from you when you try this on a
Windows 10 machine.
Sal
On Sat., Jul. 6, 2019, 1:07 a.m. Robert Cartwright, rcartwright@users.sourceforge.net wrote:
Related
Support Requests: #352
Hi again Robert,
So I followed your suggestion. I uninstalled OracleJRE and then tried
double clicking on exe again and same result. I tried double clicking on
jar file but it
didn't work as it seemed that the system didn't know where to find the JRE.
However I used the command prompt and DrJava loaded just fine and worked
just fine. Maybe your suggestion about the registry being mucked up could
be the issue after all?
I'd still love to hear how it goes for you when you try on your Windows 10
machine.
Thanks,
Sal
On Sat, Jul 6, 2019 at 1:07 AM Robert Cartwright rcartwright@users.sourceforge.net wrote:
Related
Support Requests: #352
When I tried running DrJava with OpenJDK8 on Windows 10, it did not work as
well as I had expected. The primary problem is that DrJava cannot find the
tools.jar file (containing javac, the Java compiler) in the OpenJDK8
installation. I used the Azul Systems packaging of the 64 bit OpenJDK8
which puts the installation file tree in C:Program Files/Zulu, a location
that DrJava does not currently inspect. I tried a quick hack on the DrJava
code base to look in this location, but something is going wrong that will
take me time to debug. Since I removed Oracle JDK8 when I installed
OpenJDK8, DrJava could not find a compiler and defaulted to an old Eclipse
open source compiler that we bundle in the drjava.jar file. For some
reason, the Eclipse compiler thinks it is compiling Java 6 source and flags
errors if Java 7 features are used in source code. I also tried a quick
fix for this problem but it did not work. I updated the Eclipse batch
compiler to a Java 8 version (ecj-4.6.3) but the newer compiler still
thinks it is compiling Java 6 source code for reasons I have yet to
determine. I am going on a family vacation tomorrow for about a week but I
will dig more deeply into DrJava internals to fix these problems after I
get back. In the meantime, I uploaded a new build of DrJava to
www.cs.rice.edu/~javaplt/drjavarice which includes the newer Eclipse
compiler but it still thinks it is supposed to compile Java 6 source code
so it does not appear to work any better than the current release from
drjava.org. I will fix these problems and release a new OpenJDK8
compatible release after I get back. It should be working by late July,
which I hope is soon enough for teachers planning to use DrJava next school
year.
On Fri, Jul 5, 2019 at 5:25 PM Sal Iacono icons@users.sourceforge.net
wrote:
Related
Support Requests: #352
Thanks against for your quick response. I really appreciate your efforts.
Hope you have a great vacation with your family.
Sal
On Sat., Jul. 6, 2019, 7:01 p.m. Robert Cartwright, rcartwright@users.sourceforge.net wrote:
Related
Support Requests: #352
...again... Not against... Autocorrect...
Sal
On Sat., Jul. 6, 2019, 7:39 p.m. Sal Iacono, icons@users.sourceforge.net
wrote:
Related
Support Requests: #352
I just uploaded a new version of DrJava (2019-220051) that should work on any version of the Java 8 JRE or JDK; includes the open source OpenJDK 8 Java compiler.
Hi Robert,
I just got back from my vacation to find your email. Thanks so much for
doing this. I'll be looking into this very soon as our school year starts
in one week.
I had a quick look at the website and noticed that you have uploaded a new
jar version but not new windows/mac app versions. I hate to bother you with
this but will you be adding a new app versions that supports OpenJDK? The
command line is restricted on my school's computers for students so they
won't be able launch the jar version. Plus the app version is much easier
to get them to use at home as well.
Thanks,
Sal
On Tue, Aug 13, 2019 at 7:00 PM Robert Cartwright rcartwright@users.sourceforge.net wrote:
Related
Support Requests: #352