org.xwiki.velocity.introspection
Class LinkingUberspector

java.lang.Object
  org.apache.velocity.util.introspection.UberspectImpl
      org.xwiki.velocity.introspection.LinkingUberspector

All Implemented Interfaces:

org.apache.velocity.util.introspection.Uberspect, org.apache.velocity.util.introspection.UberspectLoggable, org.apache.velocity.util.RuntimeServicesAware

public class LinkingUberspector
extends org.apache.velocity.util.introspection.UberspectImpl
implements org.apache.velocity.util.introspection.Uberspect, org.apache.velocity.util.RuntimeServicesAware, org.apache.velocity.util.introspection.UberspectLoggable

Since the current version of the Velocity engine (1.5) does not allow more than one uberspector, this class is a workaround. It manually constructs an array of uberspectors, loading the classes in the order defined in the "runtime.introspector.uberspect.arrayClasses" property, and after that forwards calls to each of the uberspectors, in order, until one of them returns something different than null. Note that the calls will be made from the leftmost class to the rightmost one. This allows building and combining different small uberspectors that perform a specialised search for methods, instead of bloating a single class with different introspection tricks.

This is not actually part of the array, but is more of a handle that allows the calls intended for only one uberspector to reach the array. It duplicates some of the code from the velocity runtime initialization code, hoping that a future version of the engine will support this natively.

The array is defined using the configuration parameter runtime.introspector.uberspect.arrayClasses. This property should contain a list of canonical class names. Any wrong entry in the list will be ignored. If this property is not defined or contains only wrong classnames, then by default a SecureUberspector is used as the only entry in the array.

Since:

1.5RC1

Version:

$Id: LinkingUberspector.java 10959 2008-07-01 00:12:29Z sdumitriu $

See Also:

ChainingUberspector

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.velocity.util.introspection.UberspectImpl

org.apache.velocity.util.introspection.UberspectImpl.VelGetterImpl, org.apache.velocity.util.introspection.UberspectImpl.VelMethodImpl, org.apache.velocity.util.introspection.UberspectImpl.VelSetterImpl

Field Summary

static java.lang.String

UBERSPECT_ARRAY_CLASSNAMES The key of the parameter that allows defining the array of uberspectors.

Fields inherited from class org.apache.velocity.util.introspection.UberspectImpl

introspector, log

Constructor Summary

LinkingUberspector()

Method Summary

java.util.Iterator	getIterator(java.lang.Object obj, org.apache.velocity.util.introspection.Info i)
org.apache.velocity.util.introspection.VelMethod	getMethod(java.lang.Object obj, java.lang.String methodName, java.lang.Object[] args, org.apache.velocity.util.introspection.Info i)
org.apache.velocity.util.introspection.VelPropertyGet	getPropertyGet(java.lang.Object obj, java.lang.String identifier, org.apache.velocity.util.introspection.Info i)
org.apache.velocity.util.introspection.VelPropertySet	getPropertySet(java.lang.Object obj, java.lang.String identifier, java.lang.Object arg, org.apache.velocity.util.introspection.Info i)
void	init()
protected void	initializeUberspector(java.lang.String classname) Instantiates and initializes an uberspector class and adds it to the array.
protected org.apache.velocity.util.introspection.Uberspect	instantiateUberspector(java.lang.String classname) Tries to create an uberspector instance using reflection.
void	setRuntimeServices(org.apache.velocity.runtime.RuntimeServices rs)

Methods inherited from class org.apache.velocity.util.introspection.UberspectImpl

setLog, setRuntimeLogger

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.velocity.util.introspection.UberspectLoggable

setLog, setRuntimeLogger

Field Detail

UBERSPECT_ARRAY_CLASSNAMES

public static final java.lang.String UBERSPECT_ARRAY_CLASSNAMES

The key of the parameter that allows defining the array of uberspectors.

See Also:

Constant Field Values

Constructor Detail

LinkingUberspector

public LinkingUberspector()

Method Detail

setRuntimeServices

public void setRuntimeServices(org.apache.velocity.runtime.RuntimeServices rs)

Specified by:

setRuntimeServices in interface org.apache.velocity.util.RuntimeServicesAware

See Also:

RuntimeServicesAware.setRuntimeServices(org.apache.velocity.runtime.RuntimeServices)

init

public void init()

This implementation initializes the array of uberspectors.

Specified by:

init in interface org.apache.velocity.util.introspection.Uberspect

Overrides:

init in class org.apache.velocity.util.introspection.UberspectImpl

See Also:

Uberspect.init()

initializeUberspector

protected void initializeUberspector(java.lang.String classname)

Instantiates and initializes an uberspector class and adds it to the array. Also set the log and runtime services, if the class implements the proper interfaces.

Parameters:

classname - The name of the uberspector class to add to the chain.

instantiateUberspector

protected org.apache.velocity.util.introspection.Uberspect instantiateUberspector(java.lang.String classname)

Tries to create an uberspector instance using reflection.

Parameters:

classname - The name of the uberspector class to instantiate.

Returns:

An instance of the specified Uberspector. If the class cannot be instantiated using the default constructor, or does not implement Uberspect, null is returned.

getIterator

public java.util.Iterator getIterator(java.lang.Object obj,
                                      org.apache.velocity.util.introspection.Info i)
                               throws java.lang.Exception

Specified by:

getIterator in interface org.apache.velocity.util.introspection.Uberspect

Overrides:

getIterator in class org.apache.velocity.util.introspection.UberspectImpl

Throws:

java.lang.Exception

See Also:

Uberspect.getIterator(java.lang.Object, org.apache.velocity.util.introspection.Info)

getMethod

public org.apache.velocity.util.introspection.VelMethod getMethod(java.lang.Object obj,
                                                                  java.lang.String methodName,
                                                                  java.lang.Object[] args,
                                                                  org.apache.velocity.util.introspection.Info i)
                                                           throws java.lang.Exception

Specified by:

getMethod in interface org.apache.velocity.util.introspection.Uberspect

Overrides:

getMethod in class org.apache.velocity.util.introspection.UberspectImpl

Throws:

java.lang.Exception

See Also:

Uberspect.getMethod(java.lang.Object, java.lang.String, java.lang.Object[], org.apache.velocity.util.introspection.Info)

getPropertyGet

public org.apache.velocity.util.introspection.VelPropertyGet getPropertyGet(java.lang.Object obj,
                                                                            java.lang.String identifier,
                                                                            org.apache.velocity.util.introspection.Info i)
                                                                     throws java.lang.Exception

Specified by:

getPropertyGet in interface org.apache.velocity.util.introspection.Uberspect

Overrides:

getPropertyGet in class org.apache.velocity.util.introspection.UberspectImpl

Throws:

java.lang.Exception

See Also:

Uberspect.getPropertyGet(java.lang.Object, java.lang.String, org.apache.velocity.util.introspection.Info)

getPropertySet

public org.apache.velocity.util.introspection.VelPropertySet getPropertySet(java.lang.Object obj,
                                                                            java.lang.String identifier,
                                                                            java.lang.Object arg,
                                                                            org.apache.velocity.util.introspection.Info i)
                                                                     throws java.lang.Exception

Specified by:

getPropertySet in interface org.apache.velocity.util.introspection.Uberspect

Overrides:

getPropertySet in class org.apache.velocity.util.introspection.UberspectImpl

Throws:

java.lang.Exception

See Also:

Uberspect.getPropertySet(java.lang.Object, java.lang.String, java.lang.Object, org.apache.velocity.util.introspection.Info)