Good day
I have a question how to send my char array to jni c++ code? I know how send int number only..
A have this array char[] chars = password.toCharArray();
and private native void JNIEncrypt(char[] chars);
My JNI method look like this
Java_com_kru13_ndkdemos_MainActivity_JNIEncrypt( JNIEnv* env, jobject obj, ?????)
I would like to ask how it should look JNI method? I need use char array in c++ code
than you
Why not just pass it as a String, which is jstring in JNI:
// Java side
private native void JNIEncrypt(String password);
// Native JNI side
Java_com_kru13_ndkdemos_MainActivity_JNIEncrypt(JNIEnv* env, jobject thiz, jstring password);
You can then access the string JNI side via GetStringChars() and related or GetStringUTFChars(). For example:
const char* utf8 = env->GetStringUTFChars(password, NULL);
// do something with utf8
env->ReleaseStringUTFChars(password, utf8);
It would be:
Java_com_kru13_ndkdemos_MainActivity_JNIEncrypt( JNIEnv* env, jobject obj, jcharArray array)
Inside the function you will have to use env->GetCharArrayElements(...).
toCharArray gets you the sequence of Unicode/UTF-16 code-units from the string. On Android, You will probably want Unicode/UTF-8 on the C++ side, but that depends on the C++ libraries you want to use. Once, you know, use the Java String class to get the bytes.
Note: GetStringUTFChars gives you modified UTF-8 code-units, which Unicode-compliant libraries reject for many characters.
private void JNIEncrypt(String string) {
JNIEncrypt(string.getBytes("UTF-8"));
// Or, for the OS default, string.getBytes()
}
private native void JNIEncrypt(byte[] chars);
