How can I use these ?

[dtianx]

I find these in nokia_7210_sdk_v1/lib/classes.zip

"RecordStoreFile.class"
static native int spaceAvailable();

native int sysOpenFile(String s);

static native int sysExists(String s);

native int sysSeek(int i, int j);

native int sysLength(int i);

native int sysTruncate(int i, int j);

native int sysClose(int i);

native int sysWrite(int i, byte abyte0[], int j, int k);

native int sysRead(int i, byte abyte0[], int j, int k);

static native int sysDeleteFile(String s);

static native int sysOpenDir();

static native int[] sysGetRMSIds(int i);

static native String sysReadDir(int i);

static native int sysCloseDir(int i);

HOW can I use these function?

[doctordwarf]

Nohow.

Well.. you can probably try using them, but there is absolutely no guarantee, that these methods will exist and will behave the same on all the phones.
If fact you even cannot be sure, that these methods will be present on a real phone at all. Maybe, they exist on the emulator only