Question

Say I have a binary string (“0 and 1s”) and I want to write this string to a binary file, how can this be done in java? I tried converting to ASCII values string, then create a ByteArrayInputStream from that but values over 127 do not display correctly. Can anyone help me with this?
My binaryToAscii method:

public static String BinaryToAscii(String bin){
    int num_of_bytes = bin.length()/8;
    StringBuilder sb = new StringBuilder();
    int index = 0;
    String byte_code;
    Character char_code;
    for (int i =0; i<num_of_bytes;i++){
        index = i*8;
        byte_code = bin.substring(index,index+8);
        int charCode = Integer.parseInt(byte_code, 2);
        char_code = new Character((char)charCode);
        sb.append(char_code);
    }
    return sb.toString();
}

Then I convert the returned string to a ByteArrayInputStream using

InputStream is = new ByteArrayInputStream(ascii.toString().getBytes());

Answer 1

you first would transform the 0 / 1 string to a byte[].

then write out using

DataOutputStream.writeByte().

read in with
DataInputStream.readUnsignedByte() // to get 0 - 255