groovy.lang

Class ProxyMetaClass

java.lang.Object

groovy.lang.MetaClassImpl

groovy.lang.ProxyMetaClass

All Implemented Interfaces:

AdaptingMetaClass, MetaClass, MetaObjectProtocol, MutableMetaClass

Direct Known Subclasses:

MockProxyMetaClass

public class ProxyMetaClass
extends MetaClassImpl
implements 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. See groovy/lang/InterceptorTest.groovy for details.

WARNING: This implementation of ProxyMetaClass is NOT thread-safe and hence should only be used for as a per-instance MetaClass running in a single thread. Do not place this MetaClass in the MetaClassRegistry as it will result in unpredictable behaviour

Author:

Dierk Koenig, Graeme Rocher

See Also:

MetaClassRegistry

Nested Class Summary

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

MetaClassImpl.Index, MetaClassImpl.MetaConstructor

Field Summary

Fields

Modifier and Type	Field and Description
protected MetaClass	adaptee
protected Interceptor	interceptor

Fields inherited from class groovy.lang.MetaClassImpl

EMPTY_ARGUMENTS, getPropertyMethod, INVOKE_METHOD_METHOD, invokeMethodMethod, isGroovyObject, isMap, metaMethodIndex, METHOD_MISSING, PROPERTY_MISSING, registry, setPropertyMethod, STATIC_METHOD_MISSING, STATIC_PROPERTY_MISSING, theCachedClass, theClass

Constructor Summary

Constructors

Constructor and Description
ProxyMetaClass(MetaClassRegistry registry, Class theClass, MetaClass adaptee)

Method Summary

Methods

Modifier and Type	Method and Description
MetaClass	getAdaptee() Returns the MetaClass that this adapter adapts
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
void	initialize() complete the initialisation process.
Object	invokeConstructor(Object[] arguments) Call invokeConstructor on adaptee with logic like in MetaClass unless we have an Interceptor.
Object	invokeMethod(Object object, String methodName, Object[] arguments) 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(MetaClass metaClass) Sets the MetaClass adapted by this MetaClass
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
Object	use(Closure closure) Use the ProxyMetaClass for the given Closure.
Object	use(GroovyObject object, Closure closure) Use the ProxyMetaClass for the given Closure.

Methods inherited from class groovy.lang.MetaClassImpl

addMetaBeanProperty, addMetaMethod, addMetaMethodToIndex, addNewInstanceMethod, addNewStaticMethod, applyPropertyDescriptors, checkIfGroovyObjectMethod, checkInitalised, chooseMethod, clearInvocationCaches, createConstructorSite, createPogoCallCurrentSite, createPogoCallSite, createPojoCallSite, createStaticSite, dropMethodCache, dropStaticMethodCache, findMethodInClassHierarchy, findMixinMethod, findOwnMethod, findPropertyInClassHierarchy, getAdditionalMetaMethods, getAttribute, getAttribute, getAttribute, getClassInfo, getClassNode, getEffectiveGetMetaProperty, getMetaMethod, getMetaMethods, getMetaProperty, getMethods, getMethodWithCaching, getMethodWithoutCaching, getProperties, getProperty, getRegistry, getStaticMetaMethod, getSubclassMetaMethods, getSuperClasses, getTheCachedClass, getTheClass, getVersion, hasProperty, incVersion, invokeMethod, invokeMethod, invokeMissingMethod, invokeMissingProperty, invokeStaticMissingProperty, isGroovyObject, isInitialized, isModified, onGetPropertyFoundInHierarchy, onInvokeMethodFoundInHierarchy, onMixinMethodFound, onSetPropertyFoundInHierarchy, onSuperMethodFoundInHierarchy, onSuperPropertyFoundInHierarchy, pickMethod, respondsTo, respondsTo, retrieveConstructor, retrieveConstructor, 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, invokeMethod, invokeMissingMethod, invokeMissingProperty, pickMethod, selectConstructorAndTransformArguments, setAttribute

Methods inherited from interface groovy.lang.MetaObjectProtocol

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

Field Detail

adaptee

protected MetaClass adaptee

interceptor

protected Interceptor interceptor

Constructor Detail

ProxyMetaClass

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

Parameters:

adaptee - the MetaClass to decorate with interceptability

Throws:

IntrospectionException

Method Detail

getInstance

public static ProxyMetaClass getInstance(Class theClass)
                                  throws IntrospectionException

convenience factory method for the most usual case.

Throws:

IntrospectionException

initialize

public void initialize()

Description copied from interface: MetaClass

complete the initialisation process. After this method is called no methods should be added to the meta class. Invocation of methods or access to fields/properties is forbidden unless this method is called. This method should contain any initialisation code, taking a longer time to complete. An example is the creation of the Reflector. It is suggested to synchronize this method.

Specified by:

initialize in interface MetaClass

Overrides:

initialize in class MetaClassImpl

use

public Object use(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 Object use(GroovyObject object,
         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

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

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 MetaObjectProtocol

Overrides:

invokeMethod in class MetaClassImpl

Parameters:

object - The instance which the method is invoked on

methodName - The name of the method

arguments - The arguments to the method

Returns:

The return value of the method which is null if the return type is void

See Also:

MissingMethodException

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 MetaObjectProtocol

Overrides:

invokeStaticMethod in class MetaClassImpl

Parameters:

object - An instance of the class returned by the getTheClass() method or the class itself

methodName - The name of the method

arguments - The arguments to the method

Returns:

The return value of the method which is null if the return type is void

See Also:

MissingMethodException

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 MetaObjectProtocol

Overrides:

invokeConstructor in class MetaClassImpl

Parameters:

arguments - The arguments to the constructor

Returns:

An instance of the java.lang.Class that this MetaObjectProtocol object applies to

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 MetaClass

Overrides:

getProperty in class MetaClassImpl

Parameters:

object - the object to invoke the getter on

property - the property name

aClass - The java.lang.Class instance that requested the property

b - Whether the call is to a super class property

b1 - ??

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 MetaClass

Overrides:

setProperty in class MetaClassImpl

Parameters:

object - The object to invoke the setter on

property - The property name to set

newValue - The new value of the property

aClass - The java.lang.Class instance that is mutating the property

b - Whether the call is to a super class property

b1 - ??

getAdaptee

public MetaClass getAdaptee()

Description copied from interface: AdaptingMetaClass

Returns the MetaClass that this adapter adapts

Specified by:

getAdaptee in interface AdaptingMetaClass

Returns:

The MetaClass instance

setAdaptee

public void setAdaptee(MetaClass metaClass)

Description copied from interface: AdaptingMetaClass

Sets the MetaClass adapted by this MetaClass

Specified by:

setAdaptee in interface AdaptingMetaClass

Parameters:

metaClass - The MetaClass to adapt