org.codehaus.groovy.grails.commons.metaclass
Class ProxyMetaClass

java.lang.Object
  groovy.lang.MetaClassImpl
      org.codehaus.groovy.grails.commons.metaclass.ProxyMetaClass

All Implemented Interfaces:

groovy.lang.AdaptingMetaClass, groovy.lang.MetaClass, groovy.lang.MetaObjectProtocol, groovy.lang.MutableMetaClass

public class ProxyMetaClass
extends groovy.lang.MetaClassImpl
implements groovy.lang.AdaptingMetaClass

As subclass of MetaClass, ProxyMetaClass manages calls from Groovy Objects to POJOs. It enriches MetaClass with the feature of making method invokations interceptable by an Interceptor. To this end, it acts as a decorator (decorator pattern) allowing to add or withdraw this feature at runtime. This is based on original code by Dierk Koenig, but uses a callback object for thread safety and supports not only method interception, but property and constructor interception too.

Author:

Dierk Koenig, Graeme Rocher

Nested Class Summary

Nested classes/interfaces inherited from class groovy.lang.MetaClassImpl

groovy.lang.MetaClassImpl.Index

Field Summary

protected groovy.lang.MetaClass	adaptee
protected Interceptor	interceptor

Fields inherited from class groovy.lang.MetaClassImpl

EMPTY_CLASS_ARRAY, isGroovyObject, isMap, LOG, METHOD_MISSING, PROPERTY_MISSING, registry, STATIC_METHOD_MISSING, STATIC_PROPERTY_MISSING, theCachedClass, theClass

Constructor Summary

ProxyMetaClass(groovy.lang.MetaClassRegistry registry, Class theClass, groovy.lang.MetaClass adaptee)

Method Summary

groovy.lang.MetaClass	getAdaptee()
static ProxyMetaClass	getInstance(Class theClass) convenience factory method for the most usual case.
Interceptor	getInterceptor()
Object	getProperty(Class aClass, Object object, String property, boolean b, boolean b1) Interceptors the call to getProperty if a PropertyAccessInterceptor is available
Object	invokeConstructor(Object[] arguments) Call invokeConstructor on adaptee with logic like in MetaClass unless we have an Interceptor.
Object	invokeMethod(Class aClass, Object object, String methodName, Object[] arguments, boolean b, boolean b1) Call invokeMethod on adaptee with logic like in MetaClass unless we have an Interceptor.
Object	invokeStaticMethod(Object object, String methodName, Object[] arguments) Call invokeStaticMethod on adaptee with logic like in MetaClass unless we have an Interceptor.
void	setAdaptee(groovy.lang.MetaClass adaptee)
void	setInterceptor(Interceptor interceptor)
void	setProperty(Class aClass, Object object, String property, Object newValue, boolean b, boolean b1) Interceptors the call to a property setter if a PropertyAccessInterceptor is available
void	use(groovy.lang.Closure closure) Use the ProxyMetaClass for the given Closure.
void	use(groovy.lang.GroovyObject object, groovy.lang.Closure closure) Use the ProxyMetaClass for the given Closure.

Methods inherited from class groovy.lang.MetaClassImpl

addMetaBeanProperty, addMetaMethod, addNewInstanceMethod, addNewStaticMethod, checkInitalised, clearInvocationCaches, dropMethodCache, dropStaticMethodCache, getAttribute, getAttribute, getAttribute, getClassNode, getMetaMethod, getMetaMethods, getMetaProperty, getMethods, getMethodWithCaching, getMethodWithoutCaching, getProperties, getProperty, getStaticMetaMethod, getTheClass, hasProperty, initialize, invokeConstructorAt, invokeMethod, invokeMethod, invokeMissingMethod, invokeMissingProperty, invokeStaticMissingProperty, isGroovyObject, isInitialized, isModified, pickMethod, respondsTo, respondsTo, retrieveConstructor, retrieveMethod, retrieveStaticMethod, selectConstructorAndTransformArguments, setAttribute, setAttribute, setProperties, setProperty, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface groovy.lang.MetaClass

getAttribute, getClassNode, getMetaMethods, getMethods, getProperties, initialize, invokeMissingMethod, invokeMissingProperty, pickMethod, selectConstructorAndTransformArguments, setAttribute

Methods inherited from interface groovy.lang.MetaObjectProtocol

getAttribute, getMetaMethod, getMetaProperty, getProperty, getStaticMetaMethod, getTheClass, hasProperty, invokeMethod, invokeMethod, respondsTo, respondsTo, setAttribute, setProperty

Field Detail

adaptee

protected groovy.lang.MetaClass adaptee

interceptor

protected Interceptor interceptor

Constructor Detail

ProxyMetaClass

public ProxyMetaClass(groovy.lang.MetaClassRegistry registry,
                      Class theClass,
                      groovy.lang.MetaClass adaptee)
               throws IntrospectionException

Parameters:

adaptee - the MetaClass to decorate with interceptability

registry - The MetaClassRegistry instance

theClass - The class to apply this ProxyMetaClass to

Throws:

IntrospectionException - Thrown when the class cannot be introspected

Method Detail

getAdaptee

public groovy.lang.MetaClass getAdaptee()

Specified by:

getAdaptee in interface groovy.lang.AdaptingMetaClass

setAdaptee

public void setAdaptee(groovy.lang.MetaClass adaptee)

Specified by:

setAdaptee in interface groovy.lang.AdaptingMetaClass

Parameters:

adaptee - the adaptee to set

getInstance

public static ProxyMetaClass getInstance(Class theClass)
                                  throws IntrospectionException

convenience factory method for the most usual case.

Parameters:

theClass - The class to create a ProxyMetaClass for

Returns:

A new ProxyMetaClass instance

Throws:

IntrospectionException - When the class canot be introspected

use

public void use(groovy.lang.Closure closure)

Use the ProxyMetaClass for the given Closure. Cares for balanced register/unregister.

Parameters:

closure - piece of code to be executed with registered ProxyMetaClass

use

public void use(groovy.lang.GroovyObject object,
                groovy.lang.Closure closure)

Use the ProxyMetaClass for the given Closure. Cares for balanced setting/unsetting ProxyMetaClass.

Parameters:

closure - piece of code to be executed with ProxyMetaClass

object - The GroovyObject to use this ProxyMetaClass with

getInterceptor

public Interceptor getInterceptor()

Returns:

the interceptor in use or null if no interceptor is used

setInterceptor

public void setInterceptor(Interceptor interceptor)

Parameters:

interceptor - may be null to reset any interception

invokeMethod

public Object invokeMethod(Class aClass,
                           Object object,
                           String methodName,
                           Object[] arguments,
                           boolean b,
                           boolean b1)

Call invokeMethod on adaptee with logic like in MetaClass unless we have an Interceptor. With Interceptor the call is nested in its beforeInvoke and afterInvoke methods. The method call is suppressed if Interceptor.doInvoke() returns false. See Interceptor for details.

Specified by:

invokeMethod in interface groovy.lang.MetaClass

Overrides:

invokeMethod in class groovy.lang.MetaClassImpl

invokeStaticMethod

public Object invokeStaticMethod(Object object,
                                 String methodName,
                                 Object[] arguments)

Call invokeStaticMethod on adaptee with logic like in MetaClass unless we have an Interceptor. With Interceptor the call is nested in its beforeInvoke and afterInvoke methods. The method call is suppressed if Interceptor.doInvoke() returns false. See Interceptor for details.

Specified by:

invokeStaticMethod in interface groovy.lang.MetaObjectProtocol

Overrides:

invokeStaticMethod in class groovy.lang.MetaClassImpl

invokeConstructor

public Object invokeConstructor(Object[] arguments)

Call invokeConstructor on adaptee with logic like in MetaClass unless we have an Interceptor. With Interceptor the call is nested in its beforeInvoke and afterInvoke methods. The method call is suppressed if Interceptor.doInvoke() returns false. See Interceptor for details.

Specified by:

invokeConstructor in interface groovy.lang.MetaObjectProtocol

Overrides:

invokeConstructor in class groovy.lang.MetaClassImpl

getProperty

public Object getProperty(Class aClass,
                          Object object,
                          String property,
                          boolean b,
                          boolean b1)

Interceptors the call to getProperty if a PropertyAccessInterceptor is available

Specified by:

getProperty in interface groovy.lang.MetaClass

Overrides:

getProperty in class groovy.lang.MetaClassImpl

Parameters:

object - the object to invoke the getter on

property - the property name

Returns:

the value of the property

setProperty

public void setProperty(Class aClass,
                        Object object,
                        String property,
                        Object newValue,
                        boolean b,
                        boolean b1)

Interceptors the call to a property setter if a PropertyAccessInterceptor is available

Specified by:

setProperty in interface groovy.lang.MetaClass

Overrides:

setProperty in class groovy.lang.MetaClassImpl

Parameters:

object - The object to invoke the setter on

property - The property name to set

newValue - The new value of the property