Sample classes.
- By Chi-keong Iong
- August 16, 2001
Java To Go!
Exception handling using the VISITOR pattern
by Chi-keong Iong
Listing 1. Sample classes.
class A
{
public void method()
throws Exception
{
B b = new B();
try
{
b.method();
}
// Implicit Accept
catch (VisitorException ve)
{
// Callback
ve.visit(this);
}
finally { }
}
}
class B
{
public void method()
throws Exception
{
C c = new C();
try
{
c.method();
}
// Implicit Accept
catch (VisitorException ve)
{
// Callback
ve.visit(this);
}
finally { }
}
}
class C
{
public void method()
throws Exception
{
try
{
throw new
VisitorException(this);
}
// Implicit Accept
catch (VisitorException ve)
{
// Callback
ve.visit(this);
}
finally { }
}
}
class TestVisitorException
{
public void method()
throws Exception
{
A a = new A();
try
{
a.method();
}
// implicit Accept
catch (VisitorException ve)
{
// Callback
ve.visit(this);
}
finally { }
}
static void main(String[] args)
throws Exception
{
TestVisitorException tve =
new TestVisitorException();
tve.method();
}
}