How to determine import statements to use for a Cocoa class for a JNI method?
How to determine import statements to use for a Cocoa class for a JNI method?
- Subject: How to determine import statements to use for a Cocoa class for a JNI method?
- From: Rob Ross <email@hidden>
- Date: Mon, 11 Sep 2006 16:21:13 -0700
I am starting to work on writing some Cocoa code that will be
executed as a native method via JNI from a Java application.
I'm starting small, trying to create an NSString without doing
anything else to it. My method works but I get a console error
message telling me there's no current NSAutoReleasePool.
Ok, so I know how to do this in Cocoa and so I add the auto release
pool code to my native method:
#include "NSStringProcessing.h"
#import <Cocoa/Cocoa.h>
#import <JavaVM/jawt_md.h>
JNIEXPORT jstring JNICALL Java_NSStringProcessing_reverseString
(JNIEnv *env, jobject obj, jstring my_jstring)
{
NSAutoReleasePool *pool = [[NSAutoReleasePool alloc] init];
printf("In native method reverseString");
NSString *str = [NSString stringWithCString:"Hi there mom"];
[pool release];
return my_jstring; //just return the string that was passed in
}
I'm including the Cocoa.h and jawt_md.h only because that's what was
included in the sample Xcode project for the JSheets project, which I
found here: http://developer.apple.com/samplecode/JSheets/index.html
after reading this technote: http://developer.apple.com/technotes/
tn2005/tn2147.html
(I know that if I omit the include for Cocoa.h then the NSString
token causes a compiler error; I have no idea what the jawt_md.h is
for. )
Then I try to compile from the command line:
gcc -c -I/System/Library/Frameworks/JavaVM.framework/Headers -I/
System/Library/Frameworks/Cocoa.framework/Headers NSStringProcessing.m
and I get this compiler error:
NSStringProcessing.m: In function
'Java_NSStringProcessing_reverseString':
NSStringProcessing.m:7: error: 'NSAutoReleasePool' undeclared (first
use in this function)
NSStringProcessing.m:7: error: (Each undeclared identifier is
reported only once
NSStringProcessing.m:7: error: for each function it appears in.)
NSStringProcessing.m:7: error: 'pool' undeclared (first use in this
function)
This leads me to conclude I that haven't included the right header
file that contains the declaration for NSAutoReleasePool.
So how do I find the right ".h" file to include? And when I later
link, with :
gcc -dynamiclib -o libNSStringProcessing.jnilib NSStringProcessing.o -
framework JavaVM -framework Cocoa
how do I know what other -framework to include based on the headers I
previously included?
Thanks,
Rob Ross, Lead Software Engineer
E! Networks
email@hidden
---------------------------------------------------
"Beware of he who would deny you access to information, for in his
heart he dreams himself your master." -- Commissioner Pravin Lal
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Cocoa-dev mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden