bugGNU Octave - Bugs: bug #55429, javachk should be able to report...


bug #55429: javachk should be able to report whether HAVE_JAVA is enabled

Submitted by:  Mike Miller <mtmiller>
Submitted on:  Wed 09 Jan 2019 06:14:13 PM UTC  
Category:  Octave Function Severity:  1 - Wish
Priority:  3 - Low Item Group:  Feature Request
Status:  Postponed Assigned to:  None
Originator Name:  Open/Closed:  Open
Release:  dev Operating System:  Any

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Tue 26 Feb 2019 08:42:31 PM UTC, comment #2:

Octave 5 javachk returns the correct struct on success now.

The remaining issue is possibly adding more expressive error messages for different reasons of not finding Java. The error message is intended to be able to be passed directly to the 'error' function, so it should be a helpful message for the user.

Mike Miller <mtmiller>
Project Administrator
Wed 09 Jan 2019 08:00:20 PM UTC, comment #1:

This is a Matlab compatible function so we have to stay within the interface dictated by Matlab. If this works with what is needed, good, otherwise maybe a new function is still needed to differentiate "Octave has support for possibly loading Java" from "Octave has loaded Java".

I still suspect we can integrate this into 'javachk', so that javachk('jvm') can return different informative error messages like "Octave was compiled without support for Java" versus "Octave is unable to find a Java Virtual Machine under JAVA_HOME", etc.

But the return value is definitely wrong, it should always return a struct. The dimensions of the struct should be 0×1 on success, so that 'isempty' is true.

Mike Miller <mtmiller>
Project Administrator
Wed 09 Jan 2019 06:14:13 PM UTC, original submission:

In additional to detecting various run time features of Java, the function javachk should also be able to report whether HAVE_JAVA is enabled or disabled, i.e. whether the user can expect that fixing JAVA_HOME or javaclasspath will help or whether they need to install a different copy of Octave.

In addition it would be nice if the return value were a struct consistently, instead of being an empty string on success and a struct on failure.

Feel free to discuss other design ideas here. This function should be useful for user code and packages that use Java to detect and diagnose Java installation problems.

Mike Miller <mtmiller>
Project Administrator


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Follow 3 latest changes.

Date Changed by Updated Field Previous Value => Replaced by
2019-02-26 mtmiller Priority5 - Normal => 3 - Low
2019-01-09 mtmiller Carbon-CopyRemoved 80942 => -
2019-01-09 mtmiller Dependencies- => bugs #47480 is dependent

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