blob: aacecb68bd1eaee0d7ee52b5cd68761a6ad35d75 [file] [log] [blame]
/*
* Copyright 2006 The Android Open Source Project
*
* JNI helper functions.
*/
#define LOG_TAG "JNIHelp"
#include "JNIHelp.h"
#include "utils/Log.h"
#include <string.h>
#include <assert.h>
/*
* Register native JNI-callable methods.
*
* "className" looks like "java/lang/String".
*/
int jniRegisterNativeMethods(JNIEnv* env, const char* className,
const JNINativeMethod* gMethods, int numMethods)
{
jclass clazz;
LOGV("Registering %s natives\n", className);
clazz = (*env)->FindClass(env, className);
if (clazz == NULL) {
LOGE("Native registration unable to find class '%s'\n", className);
return -1;
}
if ((*env)->RegisterNatives(env, clazz, gMethods, numMethods) < 0) {
LOGE("RegisterNatives failed for '%s'\n", className);
return -1;
}
return 0;
}
/*
* Throw an exception with the specified class and an optional message.
*/
int jniThrowException(JNIEnv* env, const char* className, const char* msg)
{
jclass exceptionClass;
exceptionClass = (*env)->FindClass(env, className);
if (exceptionClass == NULL) {
LOGE("Unable to find exception class %s\n", className);
assert(0); /* fatal during dev; should always be fatal? */
return -1;
}
if ((*env)->ThrowNew(env, exceptionClass, msg) != JNI_OK) {
LOGE("Failed throwing '%s' '%s'\n", className, msg);
assert(!"failed to throw");
}
return 0;
}
/*
* Throw a java.IO.IOException, generating the message from errno.
*/
int jniThrowIOException(JNIEnv* env, int errnum)
{
// note: glibc has a nonstandard
// strerror_r that looks like this:
// char *strerror_r(int errnum, char *buf, size_t n);
const char* message;
char buffer[80];
char* ret;
buffer[0] = 0;
ret = (char*) strerror_r(errnum, buffer, sizeof(buffer));
if (((int)ret) == 0) {
//POSIX strerror_r, success
message = buffer;
} else if (((int)ret) == -1) {
//POSIX strerror_r, failure
snprintf (buffer, sizeof(buffer), "errno %d", errnum);
message = buffer;
} else {
//glibc strerror_r returning a string
message = ret;
}
return jniThrowException(env, "java/io/IOException", message);
}