J2ME(Java 2 Micro Edition)

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J2ME(Java 2 Micro Edition)
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Wireless Application ??(1)

• WAP(Wireless Application Protocol)
• 1995? ???? ???
• ????? PDA?? ?? ???? ??? ???? ??? ??? ??
• ?? ???? network server, WAP ????? ??, WAP ????,
  WML(Wireless Markup Language), WMLScript,
  microbrowser ?? ??????? ???? ?? ??? ??

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Wireless Application ??(2)

• i-Mode
• ??? NTT DoCoMo? ??
• Packet-switched network? ?? ?? ???? ???? ????? ??
  ??
• cHTML(compact HTML)??? ?? markup language? ?? ??
• cHTML? HTML? ? ????? i-Mode ????? ???? ? ???????
  ? ? ??

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J2ME? ??

• WAP? i-Mode? ??
• ??? ??, ??? ??? ?????, ????? ??? ?? ??? ?? ??
• J2ME
• ????? ?? ??? wireless application, ????
  interactive? application, ?????/??? application??
  ??? application?? ??
• ??? ???? ???? ?? ??

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J2ME? ??(1)

• ??? ???
• Write Once, Run Anywhere? ?? ??? ?? ???? ??
• ??? ??? ??? ?? ??????? ?? ?? ???? ?? ????? ??
• ????? ???? ?? ??

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J2ME? ??(2)

• ?? ????? ??
• ??? ???? ?? ??? ??? ??? ? ?? ??? ???? ??? ??? ?
  ??
• ??? network ??
• network? ??? ?? ??
• ???? ????? ?? ?? ?? ? ?? ??? ???? ????? ??

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J2ME? ??(3)

• ??? ?? ??
• Class loader, Bytecode verifier??? Security
  Manager? ????? ? ??? ??? ??
• ?? ???? ??
• ???? ???? ?? ???? ???????? ??? ???? ??? ?? ??
• J2ME? ?? network? ?? ???? ??????? ?????? ??? ? ??
  ?? ?? ????? ??
• ? ?????? ???? ???? ?? ???

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J2ME? ??(4)

• ?? ???
• J2ME? ??? ??? ???????? ??? ?? ??????? ??? ? Back
  End? ??? ?? J2EE? ?? ??? ? ??
• GUI
• ???? ??? ????? ??? ??? ??? ? ?? UI? ??? ???
  ??????? ???? ??
• ??? UI? ??? ?? ????? ?? ??? ??? ???? ??? ???
  ??????? ?? ? ??

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J2ME? ??(5)

• ????, PDA, ????, ??? TV ?? ??, ???? ????? ???,
  network ???, ? ????? ?? ???? ??????? ??? ???
• ??? ??? ??? ???? ?? ???? ???? ?? ??? ??

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Java 2? Edition

• Java 2 Enterprise Edition(J2EE)
• ???? ??? ???????
• Java 2 Standard Edition(J2SE)
• ???? ???? ???????
• Java 2 Micro Edition(J2ME)
• ?? ??? ???? ??? ?? ??? ???????

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Java 2? ???
Profile Profile Foundation Profile Personal Profile RMI Profile PDA Profile MID Profile Profile
J2EE J2SE CDC CDC CDC CLDC CLDC Configuration Edition
J2EE J2SE J2ME J2ME J2ME J2ME J2ME Configuration Edition
Hot Spot VM JVM CVM CVM CVM KVM KVM Vritual Machine
Memory 10MB 1MB 512KB 32KB Memory 10MB 1MB 512KB 32KB Memory 10MB 1MB 512KB 32KB Memory 10MB 1MB 512KB 32KB Memory 10MB 1MB 512KB 32KB Memory 10MB 1MB 512KB 32KB Memory 10MB 1MB 512KB 32KB
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J2ME? Layer(1)

• ??? OS?? 3??? ??
• Java Virtual Machine Layer
• ?? J2ME? ??? ???? ?? ??? OS? ??? ?? ??? ??? ??
• CVM? KVM
• Configuration Layer
• ?? ???? ?? ??? ??? ???? ???? ???? ??? ?? ?? ???
  ??????? ??
• Profile Layer
• ??? ???? ??? ??? ???? ?? ??? ??????? ??

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J2ME? Layer(2)

• Configuration? Profile? J2ME? ???? ??
• Configuration? Profile? ??? virtual machine? ???
  ?????? ??? ?? ???? ???

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CDC? CDLC

• CDC(Connected Limited Device Configuration)
• ????? ??? ??? ?????, 216MB? ???, 32 ?? ??? CPU?
  ??? ??, ??? TCP/IP? ???? ????? network? ????? ??
• TV ?? ??, ??? TV, ??? ????, ?? ?? ??, ???? ?????
  ???
• CDLC
• ??? ?? ??? ??? ??
• ??? ??? ?????, 128KB?? 1MB? ???, 16??? 32?? CPU?
  ???, ????? TCP/IP? ???? ?? ????? ????? network?
  ??
• ???? ???, ??? ?? ???, Palm OS? ???? PDA

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J2SE, CDC, CLDC ??? ?????? ??
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J2ME Profile

• Foundation Profile
• J2SE? API? ??? ??? JVM? ??? ?? ??? ?? Profile
• RMI Profile
• J2SE 1.3? RMI API? ?? ??? ??? CDC ??? Profile
• Personal Profile
• Personal Java ???? ??? CDC Profile
• PDAP Profile
• ???? ?? ???? ?? ??(PDA)? ?? ??? ?????? ??? ?????
  ???? CLDC Profile
• MIDP(Mobile Information Device Profile)
• ???, ??? ?? ???? ?? ??? ??? ??? ?????,
  persistence storage, network, ?????? ?? API??
  ???? Profile

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MIDP/CLDC/KVM

• MID Mobile Information Device? ????
• Native System Software Device?? ???? OS? ??
  ??????
• MIDP Applications CLDC? MIDP?? ??? ????? ????
  ??? ?? ??????
• OEM-Specific Applications CLDC? MIDP? ???? ??
  ???? ? ??? ???? ??? ????(OEM-specific Classes ??
  OEM-specific service API) ???? ??? ?? ??????
• Native Applications J2ME?? ??? ??? ??? ??? ??
  ??? ???????? ?? ?? ?? ??? decode ?? ??

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CLDC ?????

• javax.microedition.io. ???? ??
• java.io, java.net ???? ???? ?? ????? ???? ?
• ???? ??? ??
• byte, short, int, long, char, boolean
• CLDC? ??? ?? ???? ???? ??, ?? ???? ???? ????? ???
  ???? ??? float? double? ???? ???

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MIDP ?????(1)

• CLDC ??????? ??? ???? ??? ???? ??, MIDP ???????
  ??? ???? ??? ??
• javax.microedition.midlet ???? ??
• ?? MIDP ???????? ? ???? MIDlet ???? ????,
  startApp(), pauseApp(), destroyApp()? 3?? ?? ????
  ???? ?

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MIDP ?????(2)

• GUI
• ??? ???? ??? ?? ?? ??? API
• ?? ???? ???? ??? ??? ???? ?? ????? ??? ?? ?? ???
  API
• GUI? ??? ???? ??? ????? javax.microedition.lcdui
  ???? ??

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MIDP ?????(3)

• Persistent Storage
• ???? ???? ???? ????? ? ??? ??
• javax.microedition.rms ???? ??
• Network
• HttpConnection ?????? ?? MIDP ??? ????? ??. ?, ??
  MIDP? ???? HTTP ??? ??
• javax.microedition.io ???? ??

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MIDlet

• MIDP? ???? ??? ??????
• ???? ??. main() ? ?? ?? javax.microedition.MIDlet
  ???? ???? startApp(), pauseApp(), destroyApp()?
  ???? ?
• MIDlet? ??? ???

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AMS(Application Management Software)

• ???? ?? ??? ??? ????? ???? ?? MIDlet? ????? ????
  ??? ??
• MIDlet? ?? ??? ??. MIDlet? ????? AMS? CLDC????
  MIDP ???, KVM ? MIDlet?? ??? ? ?? ??? ??? ???
• ??????? ???? ??? ? ??? ? ?? ?? ???? ??? ???? ??