IP addresses
Used to identify a communication address of the network entity. Communication entity may be a computer, router or the like.
IP address classification
IPV4: 32-bit address in dotted decimal notation, such as 192.168.0.1
IPV6: 128 bits (16 bytes) is written as eight 16-bit unsigned integers, each integer expressed by four hexadecimal digits, numbers by colons (:)
Separately, such as: 3ffe: 3201: 1401: 1280: c8ff: fe4d: db39: 1984
Special IP
Local address 127.0.0.1
192.168.0.0--192.168.255.255 private address, is a non-registered address, used exclusively for the internal organization.
InetAddress:
Multiple static method
1, getLocalHost: this machine
2, getByName: according to domain DNS | IP addresses -> IP
two members of method
1, getHostAddress: return address
2, getHostName: return the computer name
port
To distinguish between different programs on your computer, it is necessary to use the port.
It indicates the port is a 16-bit binary integer, 2 bytes, corresponding to the decimal 0-65535.
Oracle, MySQL, Tomcat, QQ, msn, Thunder, 360 and other network program has its own port
For example, 0-1023 recognized port 80 port assigned to the WWW, 21 port assigned to the FTP
registered ports 1024-49151 assigned to the user process or application
dynamic / private ports 49152--65535
cmd window view ports and processes:
See all ports: netstat -ano
Check the specified port: netstat -aon | findstr "808"
Check the specified process: tasklist | findstr "808"
View specific program: Use Task Manager to view PID
InetSocketAddress
Comprising a port for a socket communication
URL
URN: Universal Resource Name Uniform Resource Name to identify resources through specific namespace a unique name or ID.
On the www, each has a unified information resource and a unique address, or Uniform Resource Locator Uniform Resource Locator.
Such as: http: //www.google.com: 80 / index.html, consists of four parts:
• http protocol
• storage resource host domain name www.google.com
• Port 80
• Resource file name index.html
API