The Design And Implementation Of Road Guidance For Java Mobile Phone

The dissertation aims at providing shortest-path information for mobile user by combinating high accurate electronic map with Java mobile phone which is becoming the technology standard of mobile phone. So user can enjoy the shortest-path serve anytime and anywhere either at home or in the move.In order to achieve this, based on Java mobile phone and electronic map, with focusing on obtaining shortest-path, how to build a map containing shortest-path is discussed. Then some key problems are studied in detail, for example, how to improve the performance of server, how to decrease the search time of getting shortest-path, how to process electronic map to make it feasible for searching shortest-path and how to implement one kind of especial shortest-path with necessary locations and avoided locations. The following four finish the task above:1 Design a three-layer architecture to implement the road guidance service for Java mobile phone. Some functions need to be implemented in each layer are explored. Many emphasis and difficulties in each layer are analyzed.2 Finish displaying shortest-path with text format or map format in mobile phone. Some extra functions are provided: save shortest-path; pan and zoom map; delete all records and delete selected record; the progress to display downloading and cancel downloading.3 How to obtain a map containing shortest-path is discussed in detail. How to improve the performance of server with share-pool technology is studied.4 A kind of heuristic function in artificial intelligence is applied to make improvement on Dijkstra's algorithm. The reason why electronic map unable to search shortest-path is analyzed, then an algorithm of connecting road and an algorithm of decomposing road are designed to process electronic map. Finish mapping starting point and end point to road network Based on electronic map. At last, one kind of special shortest path search algorithm is studied, that is some locations should go and some locations should be avoid are considered.