在使用Jni的JNIEnv->NewStringUTF的时候抛出了异常"JNI DETECTED ERROR IN APPLICATION: input is not valid Modified UTF-8: illegal start byte 0xfe "。网上搜索了一下，这个异常是由于Java虚拟机内部的dalvik/vm/CheckJni.c中的checkUtfString函数抛出的，并且JVM的这个接口明确是不支持四个字节的UTF8字符。因此需要在调用函数之前，对接口传入的字符串进行过滤，过滤函数如下：
int checkUtfString(const char* bytes)
{
const char* origBytes = bytes;
if (bytes == NULL) {
return -1;
}
while (*bytes != '\0') {
unsigned char utf8 = *(bytes++);
// Switch on the high four bits.
switch (utf8 >> 4) {
case 0x00:
case 0x01:
case 0x02:
case 0x03:
case 0x04:
case 0x05:
case 0x06:
case 0x07: {
// Bit pattern 0xxx. No need for any extra bytes.
break;
}
case 0x08:
case 0x09:
case 0x0a:
case 0x0b:
case 0x0f: {
/*printf("****JNI WARNING: illegal start byte 0x%x\n", utf8);*/
return -1;
}
case 0x0e: {
// Bit pattern 1110, so there are two additional bytes.
utf8 = *(bytes++);
if ((utf8 & 0xc0) != 0x80) {
/*printf("****JNI WARNING: illegal continuation byte 0x%x\n", utf8);*/
return -1;
}
// Fall through to take care of the final byte.
}
case 0x0c:
case 0x0d: {
// Bit pattern 110x, so there is one additional byte.
utf8 = *(bytes++);
if ((utf8 & 0xc0) != 0x80) {
/*printf("****JNI WARNING: illegal continuation byte 0x%x\n", utf8);*/
return -1;
}
break;
}
}
}
return 0;
}