面向对象技术Java.pptVIP

面向对象技术Java 面向对象技术JavaObject-Oriental Technology Java 广东科学技术职业学院计算机工程技术学院曾文权老师 Email：bless365@126.com 第9章 Java小应用程序Applet 学习目标(Course Objectives) 了解小应用程序的原理 掌握小应用程序的开发步骤 能用Java语言编写小应用程序 第9章 Java小应用程序Applet 9.1 Applet入门 9.2 Applet的开发步骤 9.3 Applet的常用方法 9.4 Applet的多媒体(Multimedia)应用 9.5 Applet间的通信 小结 9.1 Applet Introduction 引入： （1）C/B应用模式中，如何使Browser界面更为生动，即在Browser环境中实现图像表示、声音播放等多媒体功能？ （2）具有对Browser客户的交互事件处理、多线程运行、网络访问等灵活的Web功能。 （3）安全、跨平台的网络应用程序。 9.1 Applet Introduction Solution： Java Applet 9.1 Applet Definition An applet is a program written in the JavaTM programming language that can be included in an HTML page, much in the same way an image is included. When you use a Java technology-enabled browser to view a page that contains an applet, the applets code is transferred to your system and executed by the browsers Java Virtual Machine (JVM). 9.1 Applet Secutiry Applications vs. Applets (1) Similarities They both are Java programs. (2) Differences An applet is a small program that is intended not to be run on its own, but rather to be embedded inside another application. Applications vs. Applets——Privileges (1) Applets are not allowed to read from, or write to, the file system of the computer viewing the applets. (2) Applets are not allowed to run any programs on the browser’s computer. (3) Applets are not allowed to establish connections between the user’s computer and another computer except with the server where the applets are stored. 9.2 Applet的开发步骤 编辑Applet的Java源文件( Edit Source Applet) 9.2 Applet程序开发步骤 Compiling Programs: On command line javac JavaWorld.java Creating an HTML File Embeded with Applet: html title java World! Appplettitle applet code=JavaWorld.class“ width=300 height=200 /applet html Viewing Java Applets: 9.2 Applet程序开发步骤 Applet Viewer Utility : appletviewer JavaWorld.html Example: appletviewer JavaWorld.html 9.2 Applet程序开发步骤 运行结果 9.2 Applet程序开发步骤_归纳 (1) 编译Applet javac JavaWorld.java (2)