Application background From the needs of the system can be drawn as follows: Veterinary, professional expertise, pet owners, pet types, pet and pet access. These entities can be designed for the JavaBean class, such as a pet with these properties: name, identity ID, type ID, and date of birth, etc.. Pet owners and pets have the following relationship: a pet owner can have a number of pets, each pet belongs to a master; each pet may go to the clinic for many times, each veterinarian has a number of expertise, and the same expertise may have more than one. Figure three describes the system's key abstractions, and they are the model of the system. Key Technology Server hardware requirements:Processor: Pentium 3 or more; memory > =512MB; > =40G; Server side software requirements:Operating system: Windows 2000 or Windows XP; Microsoft SQL ; SERVER Web container: Tomcat 5.x; Client software requir