An Easy JNI/C++ Question

[Joemama]

Hey everyone! How do you convert a jchar to char and vice versa in C++? Thanks!
Joe

[jVC++]

Do you mean that you want to get or set the fields passed from your Java Env.... in C/C++ ... If that is so .... you may try this ..

Suppose you have int variable named 'myChar' in Java.....

//C Notation...
JNIEXPORT jstring JNICALL Java_RWPrnSettings_ReadPrnSettings
(JNIEnv *env, jobject obj)
{
....
jchar ch;
jClass cls;
jfieldID fid;

cls = (*env)->GetObjectClass(env,obj);
fid = (*env)->GetFieldID(env,cls,"myChar","C");

....

ch = (*env)->GetCharField(env,obj,fid); //To get Val.
.......

ch = 'a';
(*env)->SetCharField(env,obj,fid,ch); //To set Val.
...
}

For More info...
Refer to jni.h file packaged with your JDK and also an article
at SUN : http://java.sun.com/docs/books/tutorial/native1.1/

[jVC++]

BTW the method signature above is returning jstring... , if you have any others change it or others make it... 'void'...

For C++ , there will be a small change in calling the functions...
Checkout this URL for the minor changes....
http://java.sun.com/docs/books/tutorial/native1.1/implementing/cpp.html

[Joemama]

Hey thanks a lot!