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JNI problem

 
Ranch Hand
Posts: 45
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Hi all,
I guess we dont have any forum particularly for JNI... thats y posting the porblem here...
whats the difference between passing a jstring from a java program to 'c' method AND using scanf from within the 'c' code to read the string from java execution environment... somewhat like done in the following 'c' method.....
here jstring 'str' is passed from a java method AND another string is read from the command prompt using scanf("%s", buf)
why in the first case we require conversion from unicode to UTF8 and not in the second case ....

JNIEXPORT jstring JNICALL Java_HelloName_displayHelloName(JNIEnv *env, jobject obj, jstring str)
{
char buf[128];
const char *s = (*env)->GetStringUTFChars(env, str, 0);
printf("Hello , %s\n",s);
(*env)->ReleaseStringUTFChars(env, str, s);
scanf("%s", buf);
return (*env)->NewStringUTF(env, buf);

}

 
Greenhorn
Posts: 3
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Originally posted by amit shukla:
Hi all,
I guess we dont have any forum particularly for JNI... thats y posting the porblem here...
whats the difference between passing a jstring from a java program to 'c' method AND using scanf from within the 'c' code to read the string from java execution environment... somewhat like done in the following 'c' method.....
here jstring 'str' is passed from a java method AND another string is read from the command prompt using scanf("%s", buf)
why in the first case we require conversion from unicode to UTF8 and not in the second case ....

JNIEXPORT jstring JNICALL Java_HelloName_displayHelloName(JNIEnv *env, jobject obj, jstring str)
{
char buf[128];
const char *s = (*env)->GetStringUTFChars(env, str, 0);
printf("Hello , %s\n",s);
(*env)->ReleaseStringUTFChars(env, str, s);
scanf("%s", buf);
return (*env)->NewStringUTF(env, buf);

}


Hey
If you know the answer please let me know
thanks
gat
 
Rancher
Posts: 1449
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gat98,
Please review the JavaRanch naming policy and re-register.
Thanks,
John
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