Dynamic Code Update For Java Debugging

With the rapid development of information technology, software has been widely used in almost every corner of our society. It is a huge challenge for software de-velopers to ensure the quality of software and the efficiency of software development process. As is known, software testing and debugging are the key to software quality assurance. However, for existing debuggers, if developers want to fix bugs by chang-ing software code during debugging, the debugging process needs to be stopped for code fixing and restarted after the fix is done, which incurs unnecessary time cost for developers.Dynamic software update (DSU) is the technique that updates a software system without stopping and restarting. As an attempt to eliminate the stopping of debugging process for code fix, we aim to apply DSU technique to software debugging. Through the study on existing DSU techniques we discovered that most existing DSU technique provides no support for update in debugging mode while some others only support default transformers for object update.In this thesis, we proposed a novel dynamic software update mechanism for de-bugging. Our technique supports code update in debugging mode and utilizes cus-tomized object transformer to complete object update. We implemented our approach on an existing debugger. We categorized the code update into different types based on which our approach determine whether object transformer is needed for updates.We also conducted thorough case studies in this thesis. Firstly we compared our approach with other existing techniques on some update instances. The experimen-tal result shows that our method supports more types of update. Besides, we evalu-ated both our approach and existing work on an application system. The experimental results reported that our approach can ensure correct object update with customized object transformers.