A Virtual Laboratory Platform Based On Integration Of Heterogeneous Resources

At present, distance learning is an important part of teaching reform, and virtual laboratory fills the gaps in the distance teaching pratice. However, the current virtual laboratories generally can not support the integration of heterogeneous resources, limiting their reuse and increasing the difficulty of platform development and reducing the efficiency of platform development. Also most of the experiments are demonstrative, and this limits practical ability and innovative thinking of the user. In this condition, web services technology privides a good solution to deal with these problems.Web services technology adopts XML-based and open standard protocols, shielding the software platform and programming language differences, to achieve interoperability of heterogeneous resources. And with web serivces technology, the paper proposes a virtual laboratory platform based on integration of heterogeneous resources. There are some important aspects of the platform. First, it employs the Java Applet technology, which makes users can access it anytime and anywhere. Then, all the components in the platform are developed with JavaBean and web services technology, so that the platform realizes the interaction of heterogeneous components and improves the reusability. Besides, the platform uses an independent service registry center to save the information of components, so that it can separate from the components and improve scalability and flexibility. In addition, in order to reduce the amount of data transmission and improve the efficiency of running experiments, it is presented that a scheduling mechanism based on web service composition to run experiments. What is more, users are allowed to set up experiment procedures by themselves to carry out innovative experiments. And the platform provides some interfaces for users to release components. So users can make use of their familiar programming language to develop components, and these components will be automatically deployed as web services, which users can use as same as web services provided by the platform.The paper focuses on how to use web services technology in the virtual laboratory platform, and gives a running instance. Finally, the paper summarizes the research works, and elaborates how to make the platform better in the future.