CIS 644 Aug 25 1999 tour of Java

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. Together. J 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 Hello. World. App. java /** * The Hello. World. App class implements an application that * simply displays "Hello World!" to the standard output. */ class Hello. World. App { 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) n 1. Finalize n 2. garbage collection

Interface <Name> extends <name> <block> package <Name> synchronized <block> try <block> catch ( <exception> ) <block>

Java. TM Platform 1. 1. 6 Core API Specification package java. applet 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. zip …. And more

http: //www. lne. com/Web/Java 1. 1/ http: //www. cis. ksu. edu/ Systems/Info/JDK 1. 2/index. html

Collections Implementations: Hash Table, Resizable Array, Balanced Tree, Linked List Interfaces: Set … as Hash. Set, Tree. Set List … as Array. List, Linked. List Map … as Hash. Map, Tree. Map

Communication: parameters, return parameter event … isa parameter Listener classes and interfaces, methods as: public void mose. Pressed( Mouse. Event e) adapter class exception …. implicit parameter Threads …. Runnable interface

Storage and deployment: *. java *. class *. jar …. Source file …. Compiled (byte codes) ………. Archive (zipped) Beans … reusable component, with standard bean interface, …. COM wrapper classes

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