Java All-in-One For Dummies, 5th Edition

Chapter 8

Handling Exceptions

IN THIS CHAPTER

Seeing what to do when bad things happen to good programs

Finding out all about exceptions

Using try, catch, and finally

Preventing exceptions from happening in the first place

This chapter is about what happens when Java encounters an error situation that it can’t deal with. Over the years, computer programming languages have devised many ways to deal with these types of errors. The earliest programming languages dealt with them rudely, by abruptly terminating the program and printing out the entire contents of the computer’s memory in hexadecimal. This output was called a dump.

Later programming languages tried various ways to keep the program running when serious errors occurred. In some languages, the statements that could potentially cause an error had elements added to them that would provide feedback about errors. A statement that read data from a disk file, for example, might return an error code if an I/O error occurred. Still other languages let you create a special error processing section of the program to which control would ...