Java Web 应用开发： J2EE 和 Tomcat 蔡 剑, Ph.D.

本讲内容 信息系统实施的基本概念 面向对象的程序开发 Java 技术综述

Object Technology

What is OT?

What OT is Not?

Why OT?

Data and Function

Data, Function, Objects

Modeling and Coding

Modeling and Coding 2

Reuse

Reuse of Code

Language of Design, Analysis, and Programming

Avoid Miscommunication

Benefit Provided by Objects

Procedure Language

Object Approach

Procedure Language Example

COBOL Calling Structure

Object Calling Structure

Object Program Structure

Three OOP Principles Encapsulation: binds together code and the data it manipulates; keeps both safe from outside interference and misuse Inheritance: one object acquires the properties of another object Polymorphism: allows one interface to be used for a general class of actions

Encapsulation Public instance variables Private instance variables Private method Public method

Inheritance Automobile Car Truck Sedan SUV

Polymorphism

Unified Modeling Language Cname attr:Atype op(par:Type):Rtype class oname :Class[Role] object > association 联系 generalization 泛化 realization 实现 dependency 依赖 text notes interfacepackage actor use case 类 对象 标签 接口包 动作者 用例 (extends) (implements)

Java Language

Code Compile

Java Virtual Machine

JIT Compiler

Aims of Java