Pattern matching is an important algorithm in intrusion detection system．The efficiency of this algorithm directly affects the intrusion detection system's performance. As in the process of traditional pattern matching algorithm, matches were done according to the character order in the pattern, a pattern matching algorithm based on statistics was proposed. By using the statistical characteristics of the string itself, the algorithm chooses the least frequency substring's characters in the main string as the key characters. According to this characters' position in the main string, jump matching are done. Thus the speed of pattern matching was accelerated greatly. The experiment results show that this algorithm is more efficient than other similar algorithms.

Nowadays, the procedure of IP fragments and TCP flows serial reassembling technology have not been satisfied with the high speed network requirements. Meanwhile, every whole conversation in the network is almost similar from each other. Little distinctions exist among protocols of different application layers. It is suitable for adopting parallel reassembling algorithm. A parallel reassembling algorithm in application layer was introduced. Through this method, the balance of IP fragments and TCP flows reassembling was distributed reasonably in parallel reassembly process. A two-dimensional linked list was used to save key information. Too heavy work load of NIDS was avoided. An example of SMTP protocol was analyzed thoroughly．At last, in the light of the weakness of original algorithm，an improved algorithm was put forward. The whole mission was distributed in parts and computing ability of each node was fully used. So the parallel reassembling was reached. The test result shows that the improved algorithm is much more efficient than that of the original algorithm.

Some association technologies were studied. A design model to the computer dynamic forensics system was put forward, and the detail design to the modules was given. According to the features of dynamic forensics, the method of applying data mining and multi-agent into the dynamic forensics, using multi-agent to build the architecture, using data mining technology to analyze the magnanimous data was raised. However, basic mining algorithms cannot be used to analyze digital evidence directly. So, relative improvements of basic algorithms and methods of pattern analysis were put forward, and experiment is performed to prove the feasibility.

On the basis of the browser/server application environment, uploading varied files and convenient management of upload files has become one of the problems of file management applications. The program of file upload without components was designed by using Java I/O flow. The operation of uploading files includes interfaces of submission, process and management of upload files. Upload files are able to be directly stored in the appointed catalog, and upload files can be managed through database. The implement principle of upload files using Java I/O flow and database management method were discussed. And detailed solutions and implement methods were given. 

Struts is a classic framework based on the MVC model, which integrates Java Servlets, Java ServerPages, self-defining tag and message resources into a whole framework. The software thinking of 3G communication of support services based on struts framework was discussed. According to the work principle of struts, the detailed design and implement were completed by using some software such as Windows 2000, SQL Server 2000, Tomcat 5.0 and JDK development environment. The advantages of the struts and website establishment were presented through detailed codes.