JDK Tutorials - Herong's Tutorial Examples - v6.32, by Herong Yang
Establishing a Datagram Communication Link
This section describes how to establish a datagram communication link. A server application runs a datagram socket in listen mode and a client application connects a client socket to the server socket.
To establish a datagram communication link, one application program must act as a receiver, create a datagram socket with a given local port number, and set the datagram socket in the receiving mode waiting for a datagram to arrive.
With receiver program running and waiting for a datagram to arrive, the other program can now act as a sender, create a datagram socket with a given local port number, prepare a datagram with the remote address and port number in in, and send it over.
J2SDK offers two main classes to support datagram communication:
1. java.net.DatagramSocket with methods:
2. java.net.DatagramPacket representing the datagram with methods:
The following diagram shows steps involved in sending a datagram from one program to another program using the methods provided by DatagramSocket and DatagramPacket classes:
Sender Program Receiver Program Internet Address #a Internet Address #b Step Available Port #p Available Port #q ---- ------------------- ------------------- 1 ds = new DatagramSocket(#b+#q) 2 dp = new DatagramPacket() 3 ds.receive(dp) 4 ds = new DatagramSocket() (waiting) 5 dp = new DataPacket() (waiting) 6 dp.setAddress() (waiting) 7 dp.setPort() (waiting) 8 dp.setData() (waiting) 9 ds.send(dp) (receiving datagram) 10 (dp is ready)
Table of Contents
Date, Time and Calendar Classes
Date and Time Object and String Conversion
Number Object and Numeric String Conversion
Locales, Localization Methods and Resource Bundles
Calling and Importing Classes Defined in Unnamed Packages
HashSet, Vector, HashMap and Collection Classes
Character Set Encoding Classes and Methods
Encoding Conversion Programs for Encoded Text Files
►Datagram Network Communication
►Establishing a Datagram Communication Link
DatagramServer.java - A Datagram Server Application
DatagraClient.java - A Datagram Client Application
DOM (Document Object Model) - API for XML Files
DTD (Document Type Definition) - XML Validation
XSD (XML Schema Definition) - XML Validation
XSL (Extensible Stylesheet Language)
Message Digest Algorithm Implementations in JDK
Private key and Public Key Pair Generation
PKCS#8/X.509 Private/Public Encoding Standards
Digital Signature Algorithm and Sample Program
"keytool" Commands and "keystore" Files
KeyStore and Certificate Classes
Secret Key Generation and Management
Cipher - Encryption and Decryption
The SSL (Secure Socket Layer) Protocol
SSL Socket Communication Testing Programs