java - Saving large short array android -

i'm looking way save , reload few large arrays (about 5 million short) in fastish way on android. app needs save them in way them later, can't hold them in memory...

so far, i've tried converting them byte[] array , seem save successfully, can't data back, how saving code works (it's separate functions, simplified here):

bytearrayoutputstream baos = new bytearrayoutputstream(); objectouputstream oos = new objectoutputstream(baos); oos.writeobject(data); oos.close(); baos.close(); fileoutputstream fos = new fileoutputstream(filename); // valid absolute path fos.write(baos.tobytearray()); fos.close(); 

and loading part stuck, how short[] byte[]? read database might work too, quick enough?

i've looked around stackoverflow , google , can't seem find similar problem, or @ least solution it, beginner might have missed obvious...

if data short[] , want write whole thing file, don't use buffer in memory, write directly.

objectoutputstream oos = new objectoutputstream(new fileoutputstream(filename)); try {     oos.writeobject(data); } {     oos.close(); } 

if write via objectoutputstream, have read via objectinputstream since it's not writing pure data type information. if put short[] in, short[] (you try skip bytes have analyze stream writing). applies if objectoutputstream writes bytearrayoutputstream.

if don't want handle mess, objectoutputstream does:

dataoutputstream dos = new dataoutputstream(new fileoutputstream(filename)); try {     (int = 0; < data.length; i++) {         dos.writeshort(data[i]);     } } {     dos.close(); } 

dataoutputstream writes plain data can read data directly byte[] if want. if byte order matters: it's using big-endian.

---

since approach writes single bytes instead of chucks of byte[] benefits using bufferedoutputstream in between. default uses 8kb buffer, can increased give better results. writing data convert short bytes in memory , once enough data available whole chunk pushed low level os functions write it.

int buffersize = 32 * 1024; dataoutputstream dos = new dataoutputstream(         new bufferedoutputstream(                 new fileoutputstream(filename),                 buffersize)         ); try {     (int = 0; < data.length; i++) {         dos.writeshort(data[i]);     } } {     dos.close(); }