CSC364 Lecture 02

Introduction to Networked, Distributed, and Parallel Computing
Sockets
(202601)

Transcript

1. Dr. Javier Gonzalez-Sanchez javiergs@calpoly.edu www.javiergs.info o ffi ce: 14 -227 CSC 364 Introduction to Networked, Distributed, and Parallel Computing Lecture 02. Sockets 1
2. 2 Goal This is called a system, not just a program.
3. 3 Concepts Device A (IP address) 🏭 🏭 🏭 🏭 Port Port Port Port Port Port Port Port Socket Socket Device B (IP address)
4. 4 Goal If we can make two programs talk to each other, everything else in the course has a place to land.
5. 5 De f inition A socket is a bidirection a l byte stre a m between two processes (progr a ms) Import a nt: • Not mess a ges (text) • Not objects • Just bytes
6. 6 Why they matters? Sockets a re used everywhere: • HTTP servers • Multipl a yer g a mes • Distributed d a t a b a ses • ROS nodes S a me ide a s. Bigger sc a le.
7. 7 Client - Server Architecture Server 1. Cre a te socket 2. Bind to port 3. Listen 4. Accept connection Client 1. Cre a te socket 2. Connect to server 3. Send / receive d a t a
8. Note
9. 9 Localhost or 127.0.0.1 loc a lhost A hostn a me th a t me a ns this computer 127.0.0.1 The IP a ddress of the loopb a ck interf a ce ➡ Both refer to the s a me m a chine you a re running on
10. 10 How to Get Your IP Address m a cOS / Linux ifcon f ig Look for inet under en0 (Wi-Fi) or en1. Windows (Comm a nd Prompt or PowerShell) ipcon f ig Look for IPv4 Address.
11. Client-Server Sockets
12. Client-Server 12
13. Implementation :: Server 13 chrestomathy: https://www.javatpoint.com/socket-programming
14. Implementation :: Client 14 chrestomathy: https://www.javatpoint.com/socket-programming
15. 15 Homework Run the example Break it!
16. 16 Failure Is Normal Try this: • Kill the server • Disconnect the client • Send inv a lid d a t a Common errors: • Connection refused • Timeout
17. 17 Questions
18. Lab 02. Object-Oriented Programming Refresher II
19. Previously
20. 20 Paint App
21. 21 Blueprint (First Draft)
26. Next
27. 27 Paint App
28. class TheNanny implements ActionListener { public void actionPerformed (ActionEvent e) { } }
29. 29 Paint App
30. class MyVeryOwnCenterPanel extends JPanel { public void paintComponent (Graphics g) { } }
31. class TheMouseNanny implements MouseListener { public void mousePressed (MouseEvent e) { } public void mouseClicked(MouseEvent e) { } public void mouseReleased(MouseEvent e) { } public void mouseEntered(MouseEvent e) { } public void mouseExited(MouseEvent e) { } public void mouseDragged(MouseEvent me) { } public void mouseMoved(MouseEvent e) { } }
32. // MouseListener public void mousePressed (MouseEvent e) {} public void mouseClicked(MouseEvent e) { } public void mouseReleased(MouseEvent e) { } public void mouseEntered(MouseEvent e) { } public void mouseExited(MouseEvent e) { } public void mouseDragged(MouseEvent me) { } public void mouseMoved(MouseEvent e) { } // MouseMotionListener public void mouseDragged(MouseEvent me) { } public void mouseMoved(MouseEvent e) { }
33. 33 Paint App
34. 34 Test Yourselves https://github.com/CSC3100/App-Paint/
35. CSC 364 Introduction to Introduction to Networked, Distributed, and Parallel Computing Javier Gonzalez-Sanchez, Ph.D. javiergs@calpoly.edu Winter 2026 Copyright. These slides can only be used as study material for the class CSC 364 at Cal Poly. They cannot be distributed or used for another purpose. 35