[fpc-pascal] JNI/Android: Java events calling pascal code

patspiper patspiper at gmail.com
Wed Apr 23 13:33:32 CEST 2014


On 23/04/14 13:20, Chriss Kalogeropoulos wrote:
> Hello everyone,
>
> a couple years ago i tried the same thing. The task was to implement a 
> JavaPOS driver handler from Delphi/FPC code.
> The actual driver was implemented in C++ and it used a Java interface. 
> My code was the glue between the application (Delphi/FPC) and the 
> driver, it had to hook the events and call the appropriate methods for 
> printing etc (it was a POS printer driver).
>
> I found that the only way to hook a native implemented listener to the 
> java class was either to write a small piece of code in java to do the 
> dispatching to my code OR use dynamic compilation to create the Java 
> byte code. Basically i had to write the java code inside my dll (in a 
> constact string) and pass this to the Java compiler to create the byte 
> code in memory.
> This needed a lot of work and i dropped it since the actual java code 
> was less than 30 lines and it was very generic, so it was not worth 
> the effort.
> Check this
> http://www.javablogging.com/dynamic-in-memory-compilation/
>
> This needs Java 6 (which was not an option in my case, i had to use 
> older versions). It might help you.
> Also it needs to store the source files locally otherwise more dynamic 
> class generation will be needed.
> The link above has the info you need.

If the java code is static, why would one need dynamic compilation?

Stephano


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