What Is a Datagram?
This section describes what is a datagram - An independent and self-contained message sent over the network whose arrival, arrival time, and content are not guaranteed.
Datagram: An independent and self-contained message sent over the network
whose arrival, arrival time, and content are not guaranteed. This definition
is copied from the Sun's Java tutorial document. A datagram should at least contain the
- Address: The Internet address of the remote system.
- Port: The port number of the remote system.
- Data: The data contained in the datagram.
Datagram Socket: A logical concept represents the contact point on
the local system of a datagram communication link.
Internet Address: A unique number to identify each computer system on
Port: A number representing an entry point of on a computer system on
the Internet, where a two-way communication link can be established.
Local System: The computer system at this end of a communication
Remote System: The computer system at the other end of a two-way
A datagram communication link on the Internet involves:
- Two computer systems, each has its own Internet address.
- A port number on each computer system that is used only by this
communication link during the transmission period.
- A program on each computer system that uses this communication link.
One program must act as the receiver of the datagram, and the other
program must act as the sender.
- The receiver must create a datagram socket to represent the receiving
point of the communication link.
- The sender must create a datagram socket to represent the sending
point of the communication link.
The following diagram illustrates how application programs can use
datagram socket send data to another computer system
through a datagram communication link on the Internet:
Computer System I Computer System II
Datagram|Address a| Internet |Address b|Datagram
Sender<--->Socket|Port 1 |----------->| Port 2|Socket<--->Receiver
Table of Contents
About This JDK Tutorial Book
JDK (Java Development Kit)
Java Date-Time API
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
Character Set Encoding Maps
Encoding Conversion Programs for Encoded Text Files
Socket Network Communication
►Datagram Network Communication
►What Is a Datagram?
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
SAX (Simple API for XML)
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
SSL Client Authentication
HTTPS (Hypertext Transfer Protocol Secure)
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