Programming Wireless Devices with the Java 2 Platform, Micro Edition

Transcription

1 Programming Wireless Devices with the Java 2 Platform, Micro Edition J2ME Connected Limited Device Configuration (CLDC) Mobile Information Device Profile (MIDP) Roger Riggs Antero Taivalsaari Mark VandenBrink Jim Holliday, Editor ADDISON-WESLEY Boston San Francisco New York Toronto Montreal London Munich Paris Madrid Capetown Sydney Tokyo Singapore Mexico City

2 Contents Figures Foreword Preface Acknowledgments xiii xv xvii xxi Introduction The Wireless Internet Revolution Why Java Technology for Wireless Devices? A Bit of History J2ME Standardization Efforts 4 Overview of Java 2 Platform, Micro Edition (J2ME ) Java 2 Platform Java 2 Platform, Micro Edition (J2ME) Key Concepts of the J2ME Architecture Profiles Configurations The K Virtual Machine (KVM) 16 Goals, Requirements, and Scope High-Level Goals Dynamic delivery of Java applications and content Third-party application development Independence of network technology standards Compatibility with other wireless application standards Target Devices General Notes on Consumer Devices and Embedded Systems Requirements Hardware requirements of CLDC 27 Vll

3 3.4.2 Hardware requirements of MIDP Software requirements of CLDC Software requirements of MIDP J2ME requirements Scope of the CLDC and MIDP Standardization Efforts Scope of CLDC Scope of MIDP 31 4 High-Level Architecture and Security High-Level Architecture Security Low-level (virtual machine) security Application-level security End-to-end security 41 5 Connected Limited Device Configuration CLDC Expert Group CLDC Application Model Architectural overview The concept of a Java application Application management Java Language Specification Compatibility No floating point support No finalization Error handling limitations Java Virtual Machine Specification Compatibility No floating point support Other differences Class file verification Class file format and class loading 55 6 CLDC Libraries Background and Goals Classes Derived from J2SE System classes Data type classes Collection classes Input/output classes Calendar and time classes Additional classes 62

4 6.2.7 Exception and error classes Internationalization support Property support CLDC-Specific Classes Background and motivation The Generic Connection framework No network protocol implementations defined in CLDC Design of the Generic Connection framework Additional remarks Sample code 71 7 Mobile Information Device Profile MIDP Expert Group Areas Covered by the MIDP Specification 80 8 MIDP Application Model Limitations of the CLDC Application Model MIDlets MIDlet states MIDlet Suites MIDlet suite packaging MIDlet suite execution environment MIDP System Software Application management functionality 98 9 MIDP User Interface Libraries Structure of the MIDP User Interface API Screen model Low-level user interface High-level user interface Abstract Commands Commands and command types Command listeners Interactions with MIDlet Application Lifecycle Graphics and Canvas in the Low-Level API Redrawing mechanism Drawing model Coordinate system Clipping and translation Color model 110

5 CONTENTS Line styles Ill Fonts Ill Canvas visibility Low-level API for Events in Canvases Key events Action keys Pointer events Graphics Drawing Primitives Scaling to the Canvas Drawing lines Drawing and filling arcs Drawing and filling rectangles Drawing and filling rounded rectangles Drawing text and images Creating and Using Images Mutable and immutable images Drawing to a mutable image Animation using images Using Screens List TextBox Alert Ticker Form Using Items Item String and Stringltem Image and Imageltem TextField DateField ChoiceGroup Gauge ItemStateListener A Note on Concurrency MIDP Networking Libraries Characteristics of Wireless Data Networks Network Interface Considerations The HttpConnection Interface 138

6 States of a network connection Parsing URLs Establishing a connection HTTP request headers Using an HTTP connection HTTP response headers Sample Code (NetClientMIDlet.java) MIDP Persistence Libraries The Record Management System Manipulating Record Stores and Records Manipulating a record store Manipulating records in a record store Converting record data to and from byte arrays Filtering, comparing, listening and enumerating records Sample Code (RMSMIDlet.java) Additional MIDP APIs Timer Support Using one-shot timers Using repeating timers Sample code (TimerMIDlet.java) System Properties Application Resource Files Exiting a MIDlet Sample Applications The PhotoAlbum Application Class PhotoAlbum Class PhotoFrame Class Animation Descriptor file PhotoAlbum.jad The AddressBook Application Class AddressBookMIDlet Class SimpleRecord Class SimpleFilter Class SimpleComparator Class NetworkQuery The Sokoban Game Application Class Sokoban 237

7 CONTENTS Class SokoCanvas Class Board Class Score Development Environments for J2ME Summary 267 Appendix A: CLDC Application Programming Interface 271 Almanac Legend 274 java.lang 277 java.io 291 java.util 299 javax.microedition.io 305 Appendix B: MIDP Application Programming Interface 309 java.lang 311 java.util 313 javax.microedition.io 315 javax.microedition.lcdui 317 javax.microedition.midlet 329 javax.microedition.rms 331 Index 335