Based On Java Database Access Engine

Java have many kinds of data accessing technologies, but data accessing technologies and code mapping is adopted in all the existing mappings between data base accessing and Java object. This mapping means that if the database form changed, the code also need to be changed, which is inconvenient for modifying and upgrading.This paper mainly works over the problems in Java database accessing, probes into the existing technologies, particularly expounds the advantages, disadvantages, adaptabilities and capabilities of each technology, introduces database accessing engine (DAE) which developed from the former technologies based on Java.The paper describes the function, structure,principle and code realization of DAE in detail. The advantages of this system are embodied through vadidating of several examples and contrasting with the traditional ones.DAE based on Java uses object / relation mapping technology, namely uses XML to describe database object mode, and dynamic mapping is shaped through XML and form. Mapping is realized by the functioning Java. In this way, the database model is separated from the code, so even the database changes, we only have to modify the database model description.Meanwhile, the disadvantdges in mapping between database accessing and Java direct code will be overcome. In terms of operating database, object-faced technique is used. SQL is grouped in object-faced way, and its operating interface is reserved. The work is lightened without having to be familiar with the new tools.