RFR: 8159855: Create an SPI for tools

[Jonathan Gibbons]

Hi Robert,

When you invoke jshell from the command line through the command line 
launcher, there must surely be a simpler entry point that is invoked.  
Command line entry points don't provide Java Preferences objects, for 
example. That being said, I agree that jshell does require an input 
stream, and that is not supported by this SPI.

If you want a richer API, why do you not export a public API for others 
to access and use?

-- Jon



On 10/4/16 6:37 PM, Robert Field wrote:
> I like the idea of this SPI.  And I'd like the jshell tool to 
> launchable in this manner,
>
> Unfortunately the shape of the SPI would not allow for this.  The 
> current entry-point (which is in an internal package) is --
>
>     /**
>      * The constructor for the tool (used by tool launch via main and 
> by test
>      * harnesses to capture ins and outs.
>      * @param cmdin command line input -- snippets and commands
>      * @param cmdout command line output, feedback including errors
>      * @param cmderr start-up errors and debugging info
>      * @param console console control interaction
>      * @param userin code execution input, or null to use IOContext
>      * @param userout code execution output  -- System.out.printf("hi")
>      * @param usererr code execution error stream  -- 
> System.err.printf("Oops")
>      * @param prefs preferences to use
>      * @param locale locale to use
>      */
>     public JShellTool(InputStream cmdin, PrintStream cmdout, 
> PrintStream cmderr,
>             PrintStream console,
>             InputStream userin, PrintStream userout, PrintStream usererr,
>             Preferences prefs, Locale locale)
>
> Some of these could defaulted, but not all.
>
> Any ideas?
>
> Thanks,
> Robert
>
>
>
> On 10/04/16 16:46, Jonathan Gibbons wrote:
>> Resend with non-mostly-empty subject line!
>>
>> -- Jon
>>
>> On 10/04/2016 04:39 PM, Jonathan Gibbons wrote:
>>> Core-libs folk,
>>>
>>> Please review the following change to add a new service provider class
>>>     java.util.spi.ToolProvider
>>>
>>> which can be used provide simple "command-line" access to select JDK
>>> tools, without starting a new JVM.
>>>
>>> The following tools are updated to provide access through the new SPI:
>>>     javac, javadoc, javap, jdeps
>>>
>>> It is expected that additional tools will also be updated to provide 
>>> access,
>>> but that will be done separately.
>>>
>>> Compiler-dev folk may wish to review the changes to the langtools 
>>> repository.
>>>
>>> JBS: https://bugs.openjdk.java.net/browse/JDK-8159855
>>> Webrev: http://cr.openjdk.java.net/~jjg/8159855/webrev.03/
>>> API: 
>>> http://cr.openjdk.java.net/~jjg/8159855/api.02/java/util/spi/ToolProvider.html
>>>
>>> -- Jon
>>
>