Re: Java jni: What's Wrong here?
- From: "John J. Boyer" <john.boyer@xxxxxxxxxxxxxxxxx>
- To: programmingblind@xxxxxxxxxxxxx
- Date: Sat, 29 Jan 2011 11:54:30 -0600
For those on the list interested in jni, Sina's question about the
function retruning NULL was the key. I fixed that. Then the Java program
threw an index out of bounds exception when the native method returned,
but the method completed processing. After a little more cogitation i
fixed that also. Now the translate subcommand in BrailleBlaster works.
Next up is the emboss subcommand.
John
On Sat, Jan 29, 2011 at 11:29:14AM -0500, Sina Bahram wrote:
> Are you positive that:
>
> curObj = (*env)->GetObjectArrayElement (env, args, index);
>
> will never return null?
>
> Take care,
> Sina
>
> -----Original Message-----
> From: programmingblind-bounce@xxxxxxxxxxxxx
> [mailto:programmingblind-bounce@xxxxxxxxxxxxx] On Behalf Of John J. Boyer
> Sent: Saturday, January 29, 2011 4:36 AM
> To: programmingblind@xxxxxxxxxxxxx
> Subject: Java jni: What's Wrong here?
>
> One of the functgions in my Java bindings for liblouisutdml (Which will
> be used in BrailleBlaster) requires a variable number of arguments. The
> native method diclaration handles this with String[] The C function gets
> a jObjectArray when it is called. The function which I am pasting below
> is supposed to get each argument in turn according to the value of the
> index parameter. It produces a segmentation fault. I think the problem
> is in the line that attempts to procuce a C character string from the
> Jobject. Suggestions? Thanks.
>
> JNIEXPORT const jbyte *JNICALL
> getArg (JNIEnv * env, jobject this, jobjectArray args, jint index)
> {
> static jobject curObj = NULL;
> static const jbyte *curArg = NULL;
> if (args == NULL)
> return NULL;
> if (curObj != NULL || index == -1)
> {
> if (curArg != NULL)
> (*env)->ReleaseStringUTFChars (env, curObj, curArg);
> curArg = NULL;
> curObj = NULL;
> }
> curObj = (*env)->GetObjectArrayElement (env, args, index);
> curArg = (*env)->GetStringUTFChars (env, curObj, NULL);
> return curArg;
> }
>
> --
> John J. Boyer; President, Chief Software Developer
> Abilitiessoft, Inc.
> http://www.abilitiessoft.com
> Madison, Wisconsin USA
> Developing software for people with disabilities
>
> __________
> View the list's information and change your settings at
> //www.freelists.org/list/programmingblind
>
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--
John J. Boyer; President, Chief Software Developer
Abilitiessoft, Inc.
http://www.abilitiessoft.com
Madison, Wisconsin USA
Developing software for people with disabilities
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View the list's information and change your settings at
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