javah在eclipse中设置参数:location(javah.exe的位置)working dir(${project_loc}/src)
-classpath .;./classes -d ${project_loc}\jni -jni ${java_type_name}
回调的java代码
public class HelloWorld {
static {
System.loadLibrary("jnidemo");
} public void myCallbackFunc(String nMsg) {
Log.v("EagleTag", "back message:" + nMsg);
} private void throwException() throws NullPointerException {
throw new NullPointerException("Null pointer");
} public native String DisplayHello(String inputStr);
}
C代码
jstring JNICALL Java_com_example_jnidemo_HelloWorld_DisplayHello(JNIEnv *env,
jobject obj, jstring what) {
const jbyte *l_what;
char *result; l_what = (*env)->GetStringUTFChars(env, what, NULL);
if (l_what == NULL) {
return NULL; /* OutOfMemoryError already thrown */
} result = malloc(strlen(l_what) + );
if (result == NULL) {
return NULL;
}
sprintf(result, "中文reiver %s", l_what); //回调
char tChar[];
gJniClass = ;
gJinMethod = ; gJniClass = (*env)->GetObjectClass(env, obj);
if (gJniClass == || gJniClass == NULL)
return (*env)->NewStringUTF(env, "-1"); gJinMethod = (*env)->GetMethodID(env, gJniClass, "myCallbackFunc",
"(Ljava/lang/String;)V");
if (gJinMethod == || gJinMethod == NULL)
return (*env)->NewStringUTF(env, "-2"); strcpy(tChar, result);
(*env)->CallVoidMethod(env, obj, gJinMethod,
(*env)->NewStringUTF(env, tChar)); return (*env)->NewStringUTF(env, result);
}