Modify Example4*.java so that the ConnectionAcceptoruses print( ) to write one character at a time to the socket before issuing a printlin( ) to write an end-of-line. Recompile and run the programs. Does the message still get received in its entirety? Explain.

Question

This exercise guides you through experiments with connection-oriented datagram socket using code sample Example4.

Answer 1

The code change is as follows:
```
// create a PrinterWriter object for character-mode output
PrintWriter socketOutput =
new PrintWriter(new OutputStreamWriter(outStream));
// write a message into the data stream
for (int i=0; i socketOutput.print(message.substring(i, i+1));
socketOutput.println();

C:\tmp>Java Example4ConnectionAcceptor 12345 Good-day!
now ready accept a connection
connection accepted
message sent
data socket closed
connection socket closed

C:\tmp>Java Example4ConnectionRequestor localhost 12345
Connection request granted
waiting to read
Message received:
Good-day!
data socket closed
```

With stream-mode I/O, the data written into the stream and subsequently extracted from the stream is not synchronized, so that the granularity of the data can be of different size at the two ends. In this case, the acceptor writes one character at a time while the requestor blocks on reading a line of text – the blocking continues until the newline character is written into the socket by the acceptor.