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Message:

I encountered the same prolem and found an answer

Posted by Tina Sun on January 25, 2002 at 3:39 PM

> I am doing something very similar to what is right out of Rob Gordon's JNI book but I am getting compile errors. This should be a simple one for you guys. Please help.
> Thanks...

> Here's the code:

>
> #include
> #include
> #include
> #include "jni.h"
> #include "SAVI.H"
> #include "SAVITAG.H"
> #include "com_unisys_itv_JVendor.h"

>
> jobjectArray JNICALL Java_com_unisys_itv_JVendor_sIntReport(JNIEnv *env,
> jobject this,
> jint nx,
> jint report_format) {

>
> // Tag Data collected
> TagSet_t *tags;
> int i = 0;

> Savi_Code = Savi_Int_Report(nList[nx].id, &tags, report_format);

> if (Savi_Code == SAVI_OK) {

> // determine size of array to create
> jint arySz = (jint) tags->n_tags;
> // load the class of array elements with class loader
> jclass clazz = env->FindClass("com/unisys/itv/JSaviFullRpt");
> if (clazz == 0 ) {
> return NULL;
> }
> // create the array of Java JSaviFullRpt objects
> jobjectArray aryFullTagt = env->NewObjectArray(arySz, clazz, NULL);
> if (aryFullTagt == 0) {
> return NULL;
> }

> // create the field IDs so we can access the Java object's fields
> jfieldID fTagId_FID = env->GetFieldID(env, clazz, "tag_id", "I");

> // create the Java constructor method ID so it can be called
> jmethodID mid = env->GetMethodID(clazz, "", "()V");

> switch (report_format) {

> case FULL_REPORT:
> for (i = 0; i < tags->n_tags; i++) {
> // create the Java array element (call its no-args ctor)
> jobject thisJSaviFullRpt = env->NewObject(clazz, mid);
> env->SetObjectArrayElement(aryFullTagt, i, thisJSaviFullRpt);

> // set aryFullTagt.tag_id
> env->SetIntField(env, thisJSaviFullRpt, fTagId_FID,
> ((jint) tags->tag.FULL.tag_id));

> // delete the local reference created above
> env->DeleteLocalRef(thisJSaviFullRpt);
> }
> break;

> }

> // return the array created
> return aryFullTagt;
> }

> // report was not generated properly
> return NULL;
> }

>
> And here's the errors:

> error C2223: left of '->FindClass' must point to struct/union
> error C2275: 'jobjectArray' : illegal use of this type as an expression
> \jni.h(99) : see declaration of 'jobjectArray'
> error C2146: syntax error : missing ';' before identifier 'aryFullTagt'
> error C2065: 'aryFullTagt' : undeclared identifier
> error C2223: left of '->NewObjectArray' must point to struct/union
> error C2275: 'jfieldID' : illegal use of this type as an expression
> e:\itvclient\src_c\rwcommon\savi_dll\jni.h(118) : see declaration of 'jfieldID'

> error C2275: 'jmethodID' : illegal use of this type as an expression
> \jni.h(121) : see declaration of 'jmethodID'
> error C2146: syntax error : missing ';' before identifier 'mid'
> error C2065: 'mid' : undeclared identifier
> error C2223: left of '->GetMethodID' must point to struct/union

> error C2223: left of '->DeleteLocalRef' must point to struct/union
> warning C4047: 'return' : 'struct _jobject *' differs in levels of indirection from 'int '

> ... (more similar)

> Error executing cl.exe.

> It is like it is not finding or using the header files or using the wrong ones but I have checked to be sure the included jni.h and jni_md.h are up to date (from JBuilder5). I also made sure the class file used in FindClass is in the environment's classpath.