get directory for a class instance

[Ben.BigHair]

Hello,

Is there a means to get the the directory of a plugin from an  
instance of that plugin?  I imagine something terribly easy like...

        String thisPluginPath = IJ.getDirectory("thisPluginInstance");

I ask because I have a plugin to distribute that includes a user  
preferences file - the dialog for the plugin requires a lot of user  
input.  The input might remain essentially the same for days but at  
another time change significantly at for each use.  The trouble is  
finding the preference file relative to the plugin class file when I  
don't know where the plugin is located.  For example...

User 1 places the plugin and preference file in /plugins/ben/ .... while
User 2 places the plugin and preference file in /plugins/tom/

I have no control over this and you can imagine the troubles this  
might cause.  I realize that ImageJ has a user preference system  
which could be used for this purpose, but I prefer to to keep these  
separate from that system.  I prefer to avoid searching all of the  
plugin directories for the class name except as a last resort.

Thanks!
Ben

Ben Tupper
Bigelow Laboratory for Ocean Science
180 McKown Point Road
POB 475
West Boothbay Harbor, ME 04575

[dscho]

Hi Ben,

On Thu, 12 Jul 2007, Ben Tupper wrote:

> Is there a means to get the the directory of a plugin from an instance of
> that plugin?  I imagine something terribly easy like...
>
> String thisPluginPath = IJ.getDirectory("thisPluginInstance");
>
> I ask because I have a plugin to distribute that includes a user
> preferences file - the dialog for the plugin requires a lot of user
> input.

Good that you added what you need it for.  I was almost up and hacking a
heuristical thing.

But I guess what you really need is the method getResource() of
java.lang.Class:

        import java.io.InputStream;
        import java.net.URL;

        [...]

                URL url = getClass().getResource("myConfiguration.conf");
                if (url != null) {
                        InputStream input = url.openStream();

                        [read input]

IIRC with this incantation the file "myConfiguration.conf" is expected to
be stored in the same directory as the class.  As far as I know, this also
works when you pack your classes in a jar; in that case, the file
"myConfiguration.conf" has to be in that jar, too.

Hth,
Dscho

[Ben.BigHair]

On Jul 12, 2007, at 08:03 AM, Johannes Schindelin wrote:

> Hi Ben,
>
> On Thu, 12 Jul 2007, Ben Tupper wrote:
>
>> Is there a means to get the the directory of a plugin from an  
>> instance of
>> that plugin?  I imagine something terribly easy like...
>>
>> String thisPluginPath = IJ.getDirectory("thisPluginInstance");
>>
>> I ask because I have a plugin to distribute that includes a user
>> preferences file - the dialog for the plugin requires a lot of user
>> input.
>
> Good that you added what you need it for.  I was almost up and  
> hacking a
> heuristical thing.
>
> But I guess what you really need is the method getResource() of
> java.lang.Class:
>
> import java.io.InputStream;
> import java.net.URL;
>
> [...]
>
> URL url = getClass().getResource("myConfiguration.conf");
> if (url != null) {
> InputStream input = url.openStream();
>
> [read input]
>
> IIRC with this incantation the file "myConfiguration.conf" is  
> expected to
> be stored in the same directory as the class.  As far as I know,  
> this also
> works when you pack your classes in a jar; in that case, the file
> "myConfiguration.conf" has to be in that jar, too.
>

Hi,

Thanks for this neat trick.   In addition to what you demonstrate  
above I can also get the path to the plugin class file itself ala...


import java.io.*;
import java.net.URL;

     URL url = getClass().getResource("myClassName.class");
     File pFile = new File(url.getPath());
     String pPath = pFile.getParent() + File.separator;

I especially like this because I also distribute a macro with the  
plugin, and, to simplify my life, I decided to keep the macro with  
the plugin.   I realize that this is unorthodox but the macro only  
has meaning when called from the plugin.  I need the path to the  
macro for...

        String result = IJ.runMacroFile(stringPathToMacro, argumentString);

Thanks again,
Ben