Re: [Php-java-bridge-users] Calling a PHP script from a Java servlet directly via the file system

[<php...@li...>]

> From the examples, to reference the PHP script I should use something like:ScriptEngine
> scriptEngine = new ScriptEngineManager().getEngineByName( "php-invocable" );

Not exactly. For a servlet environment it is:

   php.java.script.servlet.EngineFactory.getInvocablePhpScriptEngine()

The difference is that the ScriptEngineManager has no information
about the servlet environment, so you cannot use the servlet context
from a script allocated from the ScriptEngineManager.

The JSR 223 script spec isn't very well designed. Implementations have
to use their own workarounds. To quote Per Bothner: "Embarrassingly, I
was a not-very-active member of the JSR-223 expert group. It would
have been better if we could have thought a little more about
scripting staticly-typed languages, but we didn't have time", see
http://per.bothner.com/blog/2009/JavaFX-scripting-changes/


> scriptEngine.eval( new URLReader( "http://localhost/test.php" );
> This does not make sense to me

I wasn't part of the JSR 223 expert group, so I don't know why they
require you to pass a specific Reader, instead of a file or URL/URI.
The URLReader is an adapter, it packages up the URI location so that
it can be passed through the JSR 223 API.


> as my PHP script is not browseable

The java_call_with_continuation() makes it invocable from the remote
continuation. It calls java_context()->call(this), so that Java can
call that.cont.call(this.cont).

If you open a local script via:

  reader = new java.io.FileReader(FILE); eng.eval(reader);

the implementation hides the above "magic".


> I'd prefer not to access my script via a new request to Tomcat

It doesn't open a URLConnection back to tomcat. PHP uses a persistent
connection to a ContextRunner: Client requests JSP. JSP creates
ScriptEngine. ScriptEngine opens URLConnection to Apache/PHP. PHP
script calls java method java_context() which invokes the bridge
machinery in the back end (a java thread is spawned) and ->call()
transfers the control from the PHP- to the current Java continuation,
which may call procedures from the PHP continuation or transfer
control back.

I fail to understand your difficulties.

If you mean the FileReader utility from EngineFactory; it is there to
allow you to create a "one shot" reader for a given reader without
having to look at the file system. The PHP file is created with the
.class file during JSP compilation, so that PHP can take advantage of
its internal cache/compilation mechanism (PHP compiles to opcode and
caches it).


> If I try to pass in a URL as a file rather than http

Why don't you simply use a FileReader?


Regards,
Jost Bökemeier