Java and the Internet

1. Promotes all kinds of connectivity
   • TCP/IP stream support at application layer
   • UDP support
   • Protocol Handlers
   • Content Handlers

2. Security
   • Security Manager to establish permissions policy
   • Customizable Class Loaders allow class encryption
   • Support for public key crytosystems

3. Reliability
   • Close to a completely specified language
   • No pointer arithmetic
   • Automatic garbage collection

4. Portability
   • Java Virtual Machine - interpreter for every platform
     Layered ontop of native operating system

5. The speed issue
   • Just in time compilers
   • Native code compilers
   • Java workstations

Connectivity

• Webserver - TCP/IP example      How it works

• Teleportation: Client      Server

• Fancy Teleportation: Client      Server

• Remote Method Invocation

Security

• Security Manager      Example      SM class      SE class

• Class Loader: Hello.java      Encrypt class file      Use

• Encrypted Protocol: InputStream      URLConnect      Handler      Rotater      Use

• Encryption: Example Use      DHKeyObject      DHEngine      Cipher
  BigInteger Class      MessageDigest Class

International

• Example      Calendar Class      Locale Class      Date Class      Timezone Class