Dr. Dobb's Journal - September 2008 - (Page 43)

d09thom_p3ds 7/14/08 9:33 AM Page 43 Instantly Search Terabytes of Text N dozens of indexed, unindexed, fielded data and full-text search options (including Unicode support for hundreds of international languages) N file parsers / converters for hit-highlighted display of all popular file types N Spider supports static and dynamic web data; highlights hits while displaying links, formatting and images intact N API supports .NET, C++, Java, databases, etc. New .NET Spider API Mobile Java: The Next Generation When you compare the lifecycle of Java ME Mobile Information Device Profile (MIDP) applications to Android applications, differences stand out. Figure 2 is the lifecycle for a MIDP application (a “MIDlet”). A typical mobile phone then might have a black-and-white 96×54 pixel screen, with 128 KB of RAM and 256 KB of nonvolatile memory. In such a constrained platform, only one MIDlet executes at a time. A MIDlet spends most of its lifecycle shuttling between two states—active, where it does work, and paused, where the phone switches the MIDlet out so that it can handle a call. However, a MIDlet isn’t completely inactive while in the paused state. It can use timers to schedule work, and create background threads to execute tasks that don’t require the UI. One problem when writing a MIDlet is that its startApp() method is called every time the phone returns it to the active state. This complicates the MIDlet’s design because you often place the initialization code in the startApp() method. The reason for locating code there (rather than in the MIDlet’s constructor) is that the specification requires that if an error occurs in the constructor’s code, the stack throws a fatal exception. This behavior rules out the possibility of recovering gracefully or displaying messages that could tell users what went wrong. Many MIDlet applications therefore set a Boolean flag so that for subsequent calls of startApp(), the initialization code is bypassed. Another complication is that there’s no set mechanism to preserve the state of a complex MIDlet when it is paused. You must save the values of key variables into its RMS yourself when pauseApp() is invoked, then restore these values when the MIDlet becomes active. h Spider Desktop wit h Spider Network wit CD/DVDs Publish for ider Web with Sp Win & .NET Engine for Linux Engine for New 64-bit The Smart Choice for Text Retrieval ® since 1991 N “Bottom line: dtSearch manages a terabyte of text in a single index and returns results in less than a second” – InfoWorld N “For combing through large amounts of data,” dtSearch “leads the market” – Network Computing N dtSearch “covers all data sources powerful Web-based engines”– eWEEK N dtSearch “searches at blazing speeds” – Computer Reseller News Test Center See www.dtsearch.com for hundreds more reviews, and hundreds of developer case studies Contact dtSearch for fully-functional evaluations 1-800-IT-FINDS www.dtsearch.com Figure 2: Lifecycle for a MIDP application. September 2008 l www.ddj.com l Dr. Dobb’s Journal 43 http://www.dtsearch.com http://www.dtsearch.com http://www.dtsearch.com http://www.ddj.com

Table of Contents Feed for the Digital Edition of Dr. Dobb's Journal - September 2008

Dr. Dobb's Journal - September 2008 Contents Friday Night Fish Fry Alia Vox Developer Diaries Developer’s Notebook A Conversation With Erik Demaine Application Lifecycle Management Meets Model-Driven Development Building a Robust Development Environment Real Users Really Matter Matching Wildcards: An Algorithm The Android Mobile Phone Platform Managing Application Thread Use Signalling Integer Overflows in Java .NET Development & the IBM WebSphere Portal Server The Agile Edge Effective Concurrency Swaine’s Flames

Dr. Dobb's Journal - September 2008

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