There are three main types of sockets: stream, which uses TCP and is reliable; raw, which provides raw data transfer over IP; and datagram, which is message-oriented. Sockets can be used for unicast, multicast, and broadcast communication as well as loopback. To open a socket in Java for a client, create a Socket object; for a server, create a ServerSocket object and then accept incoming connections. Input and output streams are created using classes like DataInputStream and PrintStream, and sockets should be closed along with their streams to free resources.

1. SOCKETS IN NACH0S Socket types: STREAM- Uses TCP which is realiable, stream oriented protocol.

2. RAW- Provides RAW data transfer directly over IP protocol.

3. DATAGRAM- Message oriented protocol.

4. SOCKETS IN NACH0S Socket use: Unicast

5. Multicast

6. Broadcast

7. Loopback

8. SOCKETS IN NACH0S Programming Client-Servidor in JAVA All the class located in the java.net package.

9. Stream classes are in the java.io package.

10. SOCKETS IN NACHOS How open a socket? For programming a client, create an object of Socket class. Socket Client; try { Client = new Socket("Machine name", PortNumber); } catch (IOException e) { System.out.println(e); }

11. SOCKETS IN NACH0S For programinng a server, in this part how you open a socket. ServerSocket Service; try { Service = new ServerSocket (PortNumber); } catch (IOException e) { System.out.println(e); }

12. When implementing a server you also need create a socket object. Socket clientSocket = null; try { clientSocket = Service.accept(); } catch (IOException e) { System.out.println(e); } SOCKETS IN NACH0S

13. SOCKETS IN NACH0S How to create an imput Stream ? You can use the DataImputStream class . DataInputStream input; try { input = new DataInputStream (Client.getInputStream()); } catch (IOException e) { System.out.println(e); }

14. SOCKETS IN NACH0S How to create an output Stream ? To the server socket using the class PrintStream or DataoutputStream of java.io PrintStream output; try { output = new PrintStream (Client.getOutputStream()); } catch (IOException e) { System.out.println(e); }

15. SOCKETS IN NACH0S How to close socket? You should always close the output and input stream before you close the socket. try { output.close (); input.close (); Client.close(); } catch (IOException e) { System.out.println(e); }