Master

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s Thesis 2006 

FACHHOCHSCHULE

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LI Hui 

STUTTGART

TECHNIK

Background 

        STUTTGART UNIVERSITY OF APPLIED 

SCIENCES 

End to End Security:

 MIDP provides a robust security  model that complies 

with  open  standards  and  protects  the  network,  applications,  and  mobile 

information devices.   

2.5.4  MIDlets 

All  applications  for  the  MID  Profile  must  be  derived  from  a  special  class,  MIDlet. 

The MIDlet class manages the life cycle of the application. It is located in the package 

javax. microedition.midlet. 

MIDlets can be compared to J2SE applets, except that their state is more independent 

from  the  display  state.  A  MIDlet  can  exist  in  four  different  states:  loaded,  active, 

paused,  and  destroyed.  Figure  5  gives  an  overview  of  the  MIDlet  lifecycle.  When  a 

MIDlet is loaded into the device and the constructor is called, it is in the loaded state. 

This  can  happen  at  any  time  before  the  program  manager  starts  the  application  by 

calling  the 

startApp()

  method.  After 

startApp() 

is  called,  the  MIDlet  is  in  the  active 

state until the program manager calls 

pauseApp()

 or 

destroyApp()

; 

pauseApp()

 pauses 

the  MIDlet,  and 

desroyApp()

  terminates  the  MIDlet.  All  state  change  callback 

methods should terminate quickly, because the state is not changed completely before 

the method returns. 

Loaded/pause

d 

DestroyApp() 

Active 

startApp() 

pauseApp(

Destroyed 

) 

Pause 

DestroyApp() 

Fig. 5: 

The life cycle of a MIDlet 

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