Optimize Transparence Persistence Store In J2EE Environment And Implements With JDO

Transparent persistence technology is one of the prominent object-oriented technologies, which includes entity beans based on J2EE platform and the third party object-relation mapping tools and JDO. It is problem in enterprise software development how to ensure performance in processing persistence date and maintain legible software architecture in the meantime. For resolving this problem, we study the characteristics of the transparent persistence technologies, and analyze the JDO architecture, life cycle management, API package structure and implementation details of persistence. Moreover, we offer optimized solution about query through transparent persistence technology.To improve the efficiency of query, author realizes that object access tier can be introduced into business tier and persistence tier in three-tier model of persistence implement. This tier introduces two data structures: index object and instance cache, so we can implement query from business tier by interpreting index object as Object ID. Object ID including physical storage information, compared with traversing JDO Object in JDO environment Object, so the method can cut down the time for accessing to disk in case index filter factor is smaller.JDO concerning the potential reduction in efficiency and performance, which results in longer delay, This thesis provide Refsort-loops connection algorithm, which refers cache-relation Object and query relation Object relies on reference sequences after sorting afresh. It can avoid reading the same reference instance and records in the same data block repeatedly. Meanwhile it can convert random reading disk into doing by table. The comparison with the Hash-loops and Probe-loops algorithm, It is proved that it can cut down the time for accessing to disk at expense of caching exterior Object in JDO environment.The concept of JDO implements the mapping between Object model and relation model smoothly, as is significant to improve development efficiency and maintain legible software architecture. This thesis provides a feasible solution to improve transparent persistence performance, based on analysis on JDO and optimization for query technology.