com.iotabits.revisitor
Class BasicReflectiveVisitor

java.lang.Object
  com.iotabits.revisitor.BasicReflectiveVisitor

All Implemented Interfaces:

iReflectiveVisitor

Direct Known Subclasses:

BinaryTreeNode.BinaryTreeNodePrinter, GraphNode.GraphPrinter

public class BasicReflectiveVisitor

extends java.lang.Object

implements iReflectiveVisitor

This class an abstract class that implements the Visitor pattern via reflection. The visit method will look for a public method in the class that matches most closely the types of the arguments passed to it.

Subclasses will need to override the implementation of the 'body' methods that handle visiting when no other methods are found. By default, the body methods (named defaultVisit(...)) throw a ReflectiveDispatchException.

Subclasses should implement "visit(arg)" methods for the types of objects that are going to be encountered.

Field Summary

static java.lang.String

VISIT_METHOD_NAME

Constructor Summary

BasicReflectiveVisitor()

Method Summary

protected void	callAccept(java.lang.Object visiting) Override this if you want the revisitor to control traversal.
protected void	defaultVisit(java.lang.Object visiting) Override this to provide different default behavior for the default visit method.
void	dispatchToVisit(java.lang.Object visiting) Find a public method that most closely matches the given types and call it.
protected java.lang.reflect.Method	findMethod(java.lang.Object visiting) Look through the class and find a method that matches the classes of the parameters.
void	visit(java.lang.Object visiting) This implements the default visit method, simply calling defaultVisit(Object):void.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

VISIT_METHOD_NAME

public static final java.lang.String VISIT_METHOD_NAME

See Also:

Constant Field Values

Constructor Detail

BasicReflectiveVisitor

public BasicReflectiveVisitor()

Method Detail

findMethod

protected java.lang.reflect.Method findMethod(java.lang.Object visiting)
                                       throws java.lang.NoSuchMethodException

Look through the class and find a method that matches the classes of the parameters.

Override this if you want to control how methods are found. By default, this uses ReflectionUtils.findCovariantMethod().

Throws:

java.lang.NoSuchMethodException

callAccept

protected void callAccept(java.lang.Object visiting)
                   throws java.lang.Exception

Override this if you want the revisitor to control traversal.

Parameters:

visiting -

Throws:

java.lang.Exception

defaultVisit

protected void defaultVisit(java.lang.Object visiting)
                     throws java.lang.Exception

Override this to provide different default behavior for the default visit method.

Parameters:

visiting -

Throws:

java.lang.Exception

dispatchToVisit

public final void dispatchToVisit(java.lang.Object visiting)
                           throws java.lang.Exception

Find a public method that most closely matches the given types and call it.

This is a template method - subclasses can alter the behavior by implementing findMethod(), callAccept(), and defaultVisit().

Specified by:

dispatchToVisit in interface iReflectiveVisitor

Parameters:

visiting -

Throws:

java.lang.Exception - The visit method threw an exception.

visit

public final void visit(java.lang.Object visiting)
                 throws java.lang.Exception

This implements the default visit method, simply calling defaultVisit(Object):void.

Specified by:

visit in interface iReflectiveVisitor

Parameters:

visiting - The object being visited.

Throws:

java.lang.Exception