Java Network Programming

Network programming:

b/S Browser/server browser server

C/S Client/server client Server

TCP/IP N computers comply with protocols and specifications to generate a communication =====> network

Original ip===> 00000000.00000000.00000000.00000000 Pure digit 32 bit, inconvenient memory

IPv4 ===> 255.255.255.255

IPv6 ===> is a 128-bit composed of numbers, Alphabet symbols! It's 4 times times the IPv4.

Ipconfig querying the IP address of this machine

Ping Localhost/127.0.0.1/::1 Testing the connectivity of this machine

119.75.213.61 If this is Baidu's website, we have to enter this value every day, not remember

Www.baidu.com is easy for us to remember

DNS Domain name Resolution!

01. Convert IP address to domain name

02. Resolve the domain name to an IP address

Port number value is 0-65535

But the port number between 0-1024 is reserved by the system, not recommended!

1 a computer

2. All computers meet the TCP/IP protocol

3. Know each other's IP and port number

4. Start communication

Network server

Mail server

Web server

Cache server

is to provide users with services of one or n computers!

TCP protocol: (transmisstion Control Protocol) transmission protocol!

1. Connection-oriented, reliable

2. Security

3. Transmission Communication protocol based on Byte stream

4. Slow transmission speed

UDP protocol: (User Datagram Protocol) Subscriber Datagram Protocol!

1. For non-connected

2. Unsafe

3. The client and server do not establish a connection prior to transmitting data

4. Fast transmission speed

Java Network Programming