Implementing the idle state

To implement the idle state:

1. Create the IdleState.java class file.

2. Import the required classes.

   import java.io.ByteArrayInputStream;
   import java.io.ByteArrayOutputStream;
   import java.io.DataInputStream;
   import java.io.InputStream;
   import java.io.OutputStream;
   import javax.obex.Operation;
   import javax.obex.ResponseCodes;

3. Set IdleState to extend ExchangerState.

   public class IdleState extends ExchangerState {

4. Create the IdleState class constructor.

       public IdleState(ExchangerStateParent _parent) {
           super(_parent);
   
       }

5. Create a method for sending the user's business card when the user initiates a card exchange.

       public int onGet(Operation op) {
           try {
               OutputStream out = op.openOutputStream();
               byte[] vCard = parent.getListener().getOwnBC(); // getting the
               // own card
   
               int vlen = vCard.length;
               byte[] tmpBuf = new byte[vlen + 4];
               System.arraycopy(vCard, 0, tmpBuf, 4, vlen);
               tmpBuf[0] = (byte) ((vlen >>> 24) & 0xff);
               tmpBuf[1] = (byte) ((vlen >>> 16) & 0xff);
               tmpBuf[2] = (byte) ((vlen >>> 8) & 0xff);
               tmpBuf[3] = (byte) ((vlen >>> 0) & 0xff);
   
               out.write(tmpBuf); // sending data
   
               op.close();
   
               return ResponseCodes.OBEX_HTTP_OK;
           } catch (Exception e) {
               return ResponseCodes.OBEX_HTTP_INTERNAL_ERROR;
           }
       }

6. Create a method for receiving a business card from an incoming Bluetooth connection.

       public int onPut(Operation op) {
           try {
               InputStream in = op.openInputStream();
               byte[] fullResult = null;
               {
                   byte[] buf = new byte[256];
                   ByteArrayOutputStream bout = new ByteArrayOutputStream(2048);
                   for (int len = in.read(buf); len >= 0; len = in.read(buf)) {
                       bout.write(buf, 0, len);
                   }
                   fullResult = bout.toByteArray();
               }
               ByteArrayInputStream bin = new ByteArrayInputStream(fullResult);
               DataInputStream din = new DataInputStream(bin);
               int size = din.readInt();
               byte[] vCard = new byte[size];
               din.read(vCard);
               // card is received
   
               op.close();
               parent.getListener().onReceiveBC(vCard);
   
               return ResponseCodes.OBEX_HTTP_OK;
           } catch (Exception e) {
               return ResponseCodes.OBEX_HTTP_INTERNAL_ERROR;
           }
       }

7. Create methods for handling sending.

       public void startSending(int oper) throws Exception {
           parent.setState(new InquiryState(parent, oper));
       }
   
       public void cancelSending() {
           // Internal error, but not fatal
       }
   }

Now that you have implemented the idle state, implement the inquiry state.