tailieunhanh - Thực hiện xử lý lỗi và gỡ lỗi

Trong khi phát triển một ứng dụng Web, bạn có thể đi qua một vài lỗi. Những lỗi này có thể xảy ra bởi vì dữ liệu không hợp lệ, hoàn cảnh bất ngờ, hoặc thậm chí thất bại phần cứng. Bất cứ khi nào một lỗi xảy ra, ứng dụng kết thúc đột ngột. Là một nhà phát triển Web chuyên nghiệp, bạn cần phải đảm bảo rằng ứng dụng của bạn có thể để xử lý lỗi. Đối với điều này, bạn cần phải xem xét tất cả các trường hợp có thể có sai sót có thể. | Implementing Error Handling and Debugging Chapter 8 While developing a Web application you may come across several errors. These errors can occur because of invalid data unexpected circumstances or even hardware failure. Whenever an error occurs the application ends abruptly. Being a professional Web developer you need to ensure that your application is able to handle errors. For this you need to consider all the possible cases of errors that can occur in an application. provides several error-handling and debugging techniques that you can use to secure your applications against common errors. This chapter discusses how to implement error-handling techniques to capture errors in a Web application. It also discusses how to add error messages to the event log. In addition it discusses how to debug Web applications. Objectives In this chapter you will learn to ỆI Handle and log errors ỆI Debug Web applications Handling and Logging Errors A Web application may contain various types of errors or bugs. Errors such as typing errors and syntax errors are detected at compile time. However run-time errors such as division by zero and type mismatch cannot be detected at compile time. Such errors can be dealt with by implementing effective error-handling and debugging techniques. For implementing effective error-handling techniques you should be able to classify errors and identify situations where errors can occur in your Web applications. This is possible only for the errors that can be anticipated such as division by zero. However there are errors such as logical errors that cannot be anticipated. To secure your application against such types of errors you need to implement debugging techniques to identify and solve the error. When an error occurs details about the error can be added to an event log. This logging of errors helps in debugging because the users can see the event log to know about the errors that occurred previously in the application. Handling