Re: [Swig-user] Fw: How to pass a char array back to java via SWIG and have it treated as a byte array ?

[William S F. <ws...@fu...>]

Andrew Marlow wrote:
> swi...@li... wrote on 25/09/2007 15:24:10:
>> "Navnidhi Sharma" <Nav...@us...> wrote on 25/09/2007 
>> 15:04:52:
>>
>>> Use vector of chars in your wrapper.
>> My C wrapper does return a vector of chars. The return type is char*. 
> 
> I am part of the way there now. I found out that if I say:
> 
> %include "various.i"
> %apply (char* BYTE) {char*data};
> 
> it does use byte[] instead of String. 
> However, I am still missing a piece of the puzzle. I also found that when 
> I say getData() to get the byte[] data the length member is set to some 
> infeasible value, probably uninitialised. I can't say I am suprised 
> because I can't see how SWIG is supposed to know how big this array is. I 
> know because there is another variable in the C API that tells me. But how 
> do I use this to tell SWIG? It's a mystery to me....
> 
The char *BYTE typemaps in various.i are input only typemaps. If you 
want to marshal char * with byte[], then you need to add the missing 
typemaps for marshalling return types, namely javaout and out. You can 
get some ideas for this from arrays_java.i.

William