In-class notes for 01/10/2018

CS 284 (MCA), Interim 2018

• Eclipse Lab assignment due at "midnight"

• Quiz this afternoon 1pm. Topics

• Quiz 1 returned before lunch if possible

This session: Lab 6: Networking communication in Java

Submitted questions on assignments and technology

Network communications in Java

• Network concepts: host name, TCP ports. (Port assignments per person)

• Basics of network communication via sockets:

  • Socket as an endpoint for communication. Need to connect sockets on different hosts.

  • The Socket and ServerSocket classes

    • Socket connect() method for attempting to connect via a "server socket" on a particular host and port.

    • ServerSocket accept() method for receiving connection requests. If an accept() call succeeds, it returns a fresh Socket object for the server to communicate to that client that requested connection.

  • Can then obtain OutputStream(s) and/or InputStream(s) from Socket objects to perform I/O operations across the network.

  • Close sockets when finished.

Exercise: Find these elements in net/Sender.java and net/Receiver.java

• Demo of net/Sender.java and net/Receiver.java

• Exercise: Compile and run these programs in class together with someone else on another Link machine.

Lab exercises and javadoc

• Objects representing individual network communications (Message classes).

• Defining constructors in Java (see constructor in Account.java)

• The javadoc documentation system; stub implementations (example: Account.java members other than constructor)

  • Annotations: /**, @param, @return, @exception, @author

  • % javadoc -author -package Account.java

  • Results: Account.html

• The class StringTokenizer for parsing strings. Methods nextToken() and countTokens().

Looking ahead

• Read Threads page in Java "text" area; submit at least one reading question by tonight "midnight"

React native GUIs - Deandre

• slides

< >