Package jadex.commons.transformation.traverser

Class Traverser

java.lang.Object

jadex.commons.transformation.traverser.Traverser

public class Traverser
extends java.lang.Object

The traverser allows to traverse an object graph deeply. Traversal processors can be used to perform specific actions on traversed object, e.g. object modifications. Does currently not allow transforming objects to other objects of another type (replacements), because objects have to be saved in the graph itself (no extra table for exchanged objects). The traverser can be used as a cloner when processors always return copies of the original objects. todo: introduce classloaders to allows for creating objects with other classloaders (e.g. convert a parameter from a sender to a receiver resource id).

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	Traverser.MODE	Available modes: PREPROCESS - Preprocess objects using the conversion processors POSTPROCESS - Postprocess objects using the conversion processors PLAIN - Ignore conversion processors

Field Summary

Fields

Modifier and Type	Field	Description
static java.lang.Object	IGNORE_RESULT
protected static Traverser	instance	The default cloner.
protected java.util.Map<java.lang.Class<?>,ITraverseProcessor>	processorcache
protected static java.util.List<ITraverseProcessor>	processors	The default traversal processors with no special actions.

Constructor Summary

Constructors

Constructor	Description
Traverser()

Method Summary

Modifier and Type	Method	Description
java.lang.Object	doTraverse(java.lang.Object object, java.lang.reflect.Type type, java.util.List<ITraverseProcessor> conversionprocessors, java.util.List<ITraverseProcessor> processors, Traverser.MODE mode, java.lang.ClassLoader targetcl, java.lang.Object context)	Traverse an object.
void	finalizeProcessing(java.lang.Object inputobject, java.lang.Object outputobject, ITraverseProcessor convproc, ITraverseProcessor proc, java.lang.Object context)	Handle objects after all processing steps have been done before object is returned.
java.lang.Class<?>	findClazz(java.lang.Object object, java.lang.ClassLoader cl)	Find the class of an object.
static java.util.List<ITraverseProcessor>	getDefaultProcessors()	Get the default traversal processors.
static Traverser	getInstance()	Get the default cloner instance.
java.lang.Object	preemptProcessing(java.lang.Object inputobject, java.lang.reflect.Type inputtype, java.lang.Object context)	Allows preemption of processing, if the return value is not null, the returned object is used and processing is skipped.
java.lang.Object	traverse(java.lang.Object object, java.lang.reflect.Type clazz, java.util.List<ITraverseProcessor> conversionprocessors, java.util.List<ITraverseProcessor> processors, Traverser.MODE mode, java.lang.ClassLoader targetcl, java.lang.Object context)	Traverse an object.
static java.lang.Object	traverseObject(java.lang.Object object, java.lang.Class<?> clazz, java.util.List<ITraverseProcessor> conversionprocessors, java.util.List<ITraverseProcessor> processors, Traverser.MODE mode, java.lang.ClassLoader targetcl, java.lang.Object context)	Traverse an object.
static java.lang.Object	traverseObject(java.lang.Object object, java.lang.Class<?> clazz, java.util.List<ITraverseProcessor> conversionprocessors, java.util.List<ITraverseProcessor> processors, Traverser.MODE mode, java.lang.Object context)	Traverse an object.
static java.lang.Object	traverseObject(java.lang.Object object, java.util.List<ITraverseProcessor> conversionprocessors, java.util.List<ITraverseProcessor> processors, Traverser.MODE mode, java.lang.ClassLoader targetcl, java.lang.Object context)	Traverse an object.
static java.lang.Object	traverseObject(java.lang.Object object, java.util.List<ITraverseProcessor> conversionprocessors, java.util.List<ITraverseProcessor> processors, Traverser.MODE mode, java.lang.Object context)	Traverse an object.

Methods inherited from class java.lang.Object

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

Field Detail

IGNORE_RESULT

public static final java.lang.Object IGNORE_RESULT

instance

protected static volatile Traverser instance

The default cloner.

processors

protected static final java.util.List<ITraverseProcessor> processors

The default traversal processors with no special actions.

processorcache

protected java.util.Map<java.lang.Class<?>,ITraverseProcessor> processorcache

Constructor Detail

Traverser

public Traverser()

Method Detail

getDefaultProcessors

public static java.util.List<ITraverseProcessor> getDefaultProcessors()

Get the default traversal processors.

Returns:

The traversal processors.

getInstance

public static Traverser getInstance()

Get the default cloner instance.

traverseObject

public static java.lang.Object traverseObject(java.lang.Object object,
                                              java.util.List<ITraverseProcessor> conversionprocessors,
                                              java.util.List<ITraverseProcessor> processors,
                                              Traverser.MODE mode,
                                              java.lang.Object context)

Traverse an object.

Parameters:

object - The object to traverse.

processors - The lists of processors.

Returns:

The traversed (or modified) object.

traverseObject

public static java.lang.Object traverseObject(java.lang.Object object,
                                              java.util.List<ITraverseProcessor> conversionprocessors,
                                              java.util.List<ITraverseProcessor> processors,
                                              Traverser.MODE mode,
                                              java.lang.ClassLoader targetcl,
                                              java.lang.Object context)

Traverse an object.

Parameters:

object - The object to traverse.

processors - The lists of processors.

targetcl - If not null, the traverser should make sure that the result object is compatible with the class loader, e.g. by cloning the object using the class loaded from the target class loader.

Returns:

The traversed (or modified) object.

traverseObject

public static java.lang.Object traverseObject(java.lang.Object object,
                                              java.lang.Class<?> clazz,
                                              java.util.List<ITraverseProcessor> conversionprocessors,
                                              java.util.List<ITraverseProcessor> processors,
                                              Traverser.MODE mode,
                                              java.lang.Object context)

Traverse an object.

Parameters:

object - The object to traverse.

processors - The lists of processors.

Returns:

The traversed (or modified) object.

traverseObject

public static java.lang.Object traverseObject(java.lang.Object object,
                                              java.lang.Class<?> clazz,
                                              java.util.List<ITraverseProcessor> conversionprocessors,
                                              java.util.List<ITraverseProcessor> processors,
                                              Traverser.MODE mode,
                                              java.lang.ClassLoader targetcl,
                                              java.lang.Object context)

Traverse an object.

Parameters:

object - The object to traverse.

processors - The lists of processors.

targetcl - If not null, the traverser should make sure that the result object is compatible with the class loader, e.g. by cloning the object using the class loaded from the target class loader.

Returns:

The traversed (or modified) object.

traverse

public java.lang.Object traverse(java.lang.Object object,
                                 java.lang.reflect.Type clazz,
                                 java.util.List<ITraverseProcessor> conversionprocessors,
                                 java.util.List<ITraverseProcessor> processors,
                                 Traverser.MODE mode,
                                 java.lang.ClassLoader targetcl,
                                 java.lang.Object context)

Traverse an object.

Parameters:

object - The object.

targetcl - If not null, the traverser should make sure that the result object is compatible with the class loader, e.g. by cloning the object using the class loaded from the target class loader.

Returns:

The processed object.

doTraverse

public java.lang.Object doTraverse(java.lang.Object object,
                                   java.lang.reflect.Type type,
                                   java.util.List<ITraverseProcessor> conversionprocessors,
                                   java.util.List<ITraverseProcessor> processors,
                                   Traverser.MODE mode,
                                   java.lang.ClassLoader targetcl,
                                   java.lang.Object context)

Traverse an object.

Parameters:

object - The object.

targetcl - If not null, the traverser should make sure that the result object is compatible with the class loader, e.g. by cloning the object using the class loaded from the target class loader.

Returns:

The processed object.

findClazz

public java.lang.Class<?> findClazz(java.lang.Object object,
                                    java.lang.ClassLoader cl)

Find the class of an object.

Parameters:

object - The object.

cl - The classloader.

Returns:

The objects class.

preemptProcessing

public java.lang.Object preemptProcessing(java.lang.Object inputobject,
                                          java.lang.reflect.Type inputtype,
                                          java.lang.Object context)

Allows preemption of processing, if the return value is not null, the returned object is used and processing is skipped.

Parameters:

inputobject - The input object

inputtype - The input class.

context - The context.

Returns:

Null to process as normal, any other object skips normal processing.

finalizeProcessing

public void finalizeProcessing(java.lang.Object inputobject,
                               java.lang.Object outputobject,
                               ITraverseProcessor convproc,
                               ITraverseProcessor proc,
                               java.lang.Object context)

Handle objects after all processing steps have been done before object is returned. Not called for objects returned by preHandle().

Parameters:

inputobject - The input object

outputobject - The object after processing.

context - The context.