Exception Handling - Java - page 478

And suppose the following is a catch block immediately following the try block:
catch (Exception e)
{
System.out.println(e.getMessage());
System.out.println("Program aborted.");
System.exit(0);
}
In this case, the method call e.getMessage() returns the string
"Input must be positive."
Exception Classes
There are more exception classes than just the single class Exception . There are more
exception classes in the standard Java libraries and you can define your own exception
classes. All the exception classes in the Java libraries have—and the exception classes
you define should have—the following properties:
1. There is a constructor that takes a single argument of type String .
2. The class has an accessor method getMessage() that can recover the string given as
an argument to the constructor when the exception object was created.
try-throw-catch
When used together, the try , throw , and catch statements are the basic mechanism for
throwing and catching exceptions. The throw statement throws the exception. The catch
block catches the exception. The throw statement is normally included in a try block. When
the exception is thrown, the try block ends and then the code in the catch block is executed.
After the catch block is completed, the code after the catch block(s) is executed (provided the
catch block has not ended the program or performed some other special action).
If no exception is thrown in the try block, then after the try block is completed, program
execution continues with the code after the catch block(s). (In other words, if no exception is
thrown, the catch block(s) are ignored.)
SYNTAX
try
{
Some_Statements
< Either a throw statement or
a method invocation that might throw an exception
or other statement that might throw an exception. >
Some_More_Statements
}