Exceptions - Beginning Java - page 354

NOTE The primary purpose for the try block is to identify code that may result in an excep-
tion being thrown. However, you can use it to contain code that doesn't throw exceptions for
the convenience of using a finally block. This can be useful when the code in the try block
hasseveralpossibleexitpoints— break or return statements,forexample—butyoualways
want to have a specific set of statements executed after the try block has been executed to
make sure things are tidied up, such as closing any open files. You can put these in a finally
block. Note that if avalue isreturned within a finally block, this return overrides anyreturn
statement executed in the try block.
Structuring a Method
You've looked at the blocks you can include in the body of a method, but it may not always be obvious how
they are combined. The first thing to get straight is that a try block plus any corresponding catch blocks
and the finally block all bunch together in that order:
try {
// Code that may throw exceptions...
} catch(ExceptionType1 e) {
// Code to handle exceptions of type ExceptionType1 or subclass
} catch(ExceptionType2 e) {
// Code to handle exceptions of type ExceptionType2 or subclass
... // more catch blocks if necessary
} finally {
// Code always to be executed after try block code
}
You can't have just a try block by itself. Each try block must always be followed by at least one block
that is either a catch block or a finally block.
You must not include other code between a try block and its catch blocks, or between the catch blocks
and the finally block. You can have other code that doesn't throw exceptions after the finally block, and
you can have multiple try blocks in a method. In this case, your method might be structured as shown in
Figure 7-2 .
FIGURE 7-2