CIS 644

Aug. 25, 1999

tour of Java

First … about the media lectures…

we are experimenting with the media format

please give feedback

... not (much) programming in Java.

We will write and compile Java declarations

(framework) for some sample problems.

TogetherJ design tool generates Java frameworks.

Classes

objects

methods

class / instance variables

constructors

observers (“get”)

generators (“set”)

mutators

inheritance (single)

signature

interface

Software architecture:

applications applets servlets

beans

file named HelloWorldApp.java

/** * The HelloWorldApp class implements an application that * simply displays "Hello World!" to the standard output. */ class HelloWorldApp { public static void main(String[ ] args) { System.out.println("Hello World!"); //out the string. } }

Import <packages>

<c_modifier> class <Name> extend <parent>

implements <interface>

{

<variables>

<methods>

}

c_modifiers: final

abstract

public

Method / variable modifiers

abstract

static

native

final

synchronized

public

private

protected

Objects:

1. declaration: 2. instantiation: new 3. initialization: 4*. Use… reference (observers) , update (mutators)

n1. Finalizen2. garbage collection

Interface <Name> extends <name>

<block>

package <Name>

synchronized <block>

try <block> catch ( <exception> ) <block>

JavaTM Platform 1.1.6 Core API Specification

package java.applet package java.awt package java.awt.event package java.awt.image package java.beans package java.io package java.lang package java.math package java.net package java.rmi package java.text package java.util package java.util.zip …. And more

http://www.lne.com/Web/Java1.1/

http://www.cis.ksu.edu/ Systems/Info/JDK1.2/index.html

Collections Implementations: Hash Table, Resizable Array, Balanced Tree, Linked List Interfaces: Set … as HashSet, TreeSet List … as ArrayList, LinkedList

Map … as HashMap, TreeMap

Communication:

parameters, return parameter

event … isa parameter

Listener classes and interfaces, methods as: public void mosePressed( MouseEvent e) adapter class

exception …. implicit parameter

Threads …. Runnable interface

Storage and deployment: *.java …. Source file *.class …. Compiled (byte codes)

*.jar ………. Archive (zipped)

Beans … reusable component, with standard bean interface, …. COM wrapper classes

End