Language of Internet Programming

Language of Internet Programming

Java Applets

Security

Portability

1. Applets:

Special java program that can transmitted over the network and 

automatically executed by a java-compatible web browser.

2. Security:

Java compatible web browser can download java applets without 

fear of viral infection and malicious agent.

3. Portable:

Java applets can be dynamically downloaded to all the various 

types of platforms connected to the internet

Why portable and Secure?

The output of java compiler is not executable code.

 Once JVM exists for a platform, any java program can run on it.

 The execution of byte code by the JVM makes java programs portable.

 Java program is confined within  the java execution environment and cannot access the other part of the computer.

Basics of Java Environments

Java programs normally undergo five phases

Edit

Programmer writes program (and stores program on disk)

Compile

Compiler creates bytecodes from program

Load

Class loader stores bytecodes in memory

Verify

Verifier ensures bytecodes do not violate security requirements

Execute

Interpreter translates bytecodes into machine language