groovy.lang.ExpandoMetaClass

All Implemented Interfaces:: GroovyObject, MetaClass, MetaObjectProtocol, MutableMetaClass

public class ExpandoMetaClass extends MetaClassImpl implements GroovyObject

ExpandoMetaClass is a MetaClass that behaves like an Expando, allowing the addition or replacement of methods, properties and constructors on the fly.

Some examples of usage:

 // defines or replaces instance method:
 metaClass.myMethod = { args -> }

 // defines a new instance method
 metaClass.myMethod << { args -> }

 // creates multiple overloaded methods of the same name
 metaClass.myMethod << { String s -> } << { Integer i -> }

 // defines or replaces a static method with the 'static' qualifier
 metaClass.'static'.myMethod = { args ->  }

 // defines a new static method with the 'static' qualifier
 metaClass.'static'.myMethod << { args ->  }

 // defines a new constructor
 metaClass.constructor << { String arg -> }

 // defines or replaces a constructor
 metaClass.constructor = { String arg -> }

 // defines a new property with an initial value of "blah"
 metaClass.myProperty = "blah"

ExpandoMetaClass also supports a DSL/builder like notation to combine multiple definitions together. So instead of this:

 Number.metaClass.multiply = { Amount amount -> amount.times(delegate) }
 Number.metaClass.div =      { Amount amount -> amount.inverse().times(delegate) }

You can also now do this:

 Number.metaClass {
     multiply { Amount amount -> amount.times(delegate) }
     div      { Amount amount -> amount.inverse().times(delegate) }
 }

ExpandoMetaClass also supports runtime mixins. While @Mixin allows you to mix in new behavior to classes you own and are designing, you can not easily mixin anything to types you didn't own, e.g. from third party libraries or from JDK library classes. Runtime mixins let you add a mixin on any type at runtime.

 interface Vehicle {
     String getName()
 }

 // Category annotation style
 @Category(Vehicle) class FlyingAbility {
     def fly() { "I'm the ${name} and I fly!" }
 }

 // traditional category style
 class DivingAbility {
     static dive(Vehicle self) { "I'm the ${self.name} and I dive!" }
 }

 // provided by a third-party, so can't augment using Mixin annotation
 class JamesBondVehicle implements Vehicle {
     String getName() { "James Bond's vehicle" }
 }

 // Can be added via metaClass, e.g.:
 // JamesBondVehicle.metaClass.mixin DivingAbility, FlyingAbility
 // Or using shorthand through DGM method on Class
 JamesBondVehicle.mixin DivingAbility, FlyingAbility

 assert new JamesBondVehicle().fly() ==
        "I'm the James Bond's vehicle and I fly!"
 assert new JamesBondVehicle().dive() ==
        "I'm the James Bond's vehicle and I dive!"

As another example, consider the following class definitions:

 class Student {
     List schedule = []
     def addLecture(String lecture) { schedule << lecture }
 }

 class Worker {
     List schedule = []
     def addMeeting(String meeting) { schedule << meeting }
 }

We can mimic a form of multiple inheritance as follows:

 class CollegeStudent {
     static { mixin Student, Worker }
 }
 new CollegeStudent().with {
     addMeeting('Performance review with Boss')
     addLecture('Learn about Groovy Mixins')
     println schedule
     println mixedIn[Student].schedule
     println mixedIn[Worker].schedule
 }

Which outputs these lines when run:

 [Performance review with Boss]
 [Learn about Groovy Mixins]
 [Performance review with Boss]

Perhaps some explanation is required here. The methods and properties of Student and Worker are added to CollegeStudent. Worker is added last, so for overlapping methods, its methods will be used, e.g. when calling schedule, it will be the schedule property (getSchedule method) from Worker that is used. The schedule property from Student will be shadowed but the mixedIn notation allows us to get to that too if we need as the last two lines show.

We can also be a little more dynamic and not require the CollegeStudent class to be defined at all, e.g.:

 def cs = new Object()
 cs.metaClass {
     mixin Student, Worker
     getSchedule {
         mixedIn[Student].schedule + mixedIn[Worker].schedule
     }
 }
 cs.with {
     addMeeting('Performance review with Boss')
     addLecture('Learn about Groovy Mixins')
     println schedule
 }

Which outputs this line when run:

 [Learn about Groovy Mixins, Performance review with Boss]

As another example, we can also define a no dup queue by mixing in some Queue and Set functionality as follows:

 def ndq = new Object()
 ndq.metaClass {
     mixin ArrayDeque
     mixin HashSet
     leftShift = { Object o  ->
         if (!mixedIn[Set].contains(o)) {
             mixedIn[Queue].push(o)
             mixedIn[Set].add(o)
         }
     }
 }
 ndq << 1
 ndq << 2
 ndq << 1
 assert ndq.size() == 2

As a final example, we sometimes need to pass such mixed in classes or objects into Java methods which require a given static type but the ExpandoMetaClass mixin approach uses a very dynamic approach based on duck typing rather than static interface definitions, so doesn't by default produce objects matching the required static type. Luckily, there is a mixins capability within ExpandoMetaClass which supports the use of Groovy's common 'as StaticType' notation to produce an object having the correct static type so that it can be passed to the Java method call in question. A slightly contrived example illustrating this feature:

 class CustomComparator implements Comparator {
     int compare(Object a, b) { return a.size() - b.size() }
 }

 class CustomCloseable implements Closeable {
     void close() { println 'Lights out - I am closing' }
 }

 import static mypackage.IOUtils.closeQuietly
 import static java.util.Collections.sort
 def o = new Object()
 o.metaClass.mixin CustomComparator, CustomCloseable
 def items = ['a', 'bbb', 'cc']
 sort(items, o as Comparator)
 println items                // => [a, cc, bbb]
 closeQuietly(o as Closeable) // => Lights out - I am closing

Further details

When using the default implementations of MetaClass, methods are only allowed to be added before initialize() is called. In other words you create a new MetaClass, add some methods and then call initialize(). If you attempt to add new methods after initialize() has been called, an error will be thrown. This is to ensure that the MetaClass can operate appropriately in multithreaded environments as it forces you to do all method additions at the beginning, before using the MetaClass.

ExpandoMetaClass differs here from the default in that it allows you to add methods after initialize has been called. This is done by setting the initialize flag internally to false and then add the methods. Since this is not thread safe it has to be done in a synchronized block. The methods to check for modification and initialization are therefore synchronized as well. Any method call done through this metaclass will first check if the it is synchronized. Should this happen during a modification, then the method cannot be selected or called unless the modification is completed.

Since:: 1.5

Nested Class Summary

Nested Classes

Modifier and Type

Class

Description

protected class

ExpandoMetaClass.ExpandoMetaConstructor

Handles the ability to use the left shift operator to append new constructors

protected class

ExpandoMetaClass.ExpandoMetaProperty

Instances of this class are returned when using the << left shift operator.

Nested classes/interfaces inherited from class groovy.lang.MetaClassImpl
MetaClassImpl.MetaConstructor
Field Summary

Fields

Modifier and Type

Field

Description

static final String

CONSTRUCTOR

Pseudo-property used by the expando DSL to define constructors.

boolean

inRegistry

Indicates whether this expando meta class is registered in the global registry.

static final String

STATIC_QUALIFIER

Pseudo-property used by the expando DSL to define static members.

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

Description

ExpandoMetaClass(MetaClassRegistry registry, Class theClass, boolean register, boolean allowChangesAfterInit, MetaMethod[] add)

Creates an expando meta class bound to a specific registry.

ExpandoMetaClass(Class theClass)

Constructs a new ExpandoMetaClass instance for the given class

ExpandoMetaClass(Class theClass, boolean register)

Constructs a new ExpandoMetaClass instance for the given class optionally placing the MetaClass in the MetaClassRegistry automatically

ExpandoMetaClass(Class theClass, boolean register, boolean allowChangesAfterInit)

Constructs a new ExpandoMetaClass instance for the given class optionally placing the MetaClass in the MetaClassRegistry automatically

ExpandoMetaClass(Class theClass, boolean register, boolean allowChangesAfterInit, MetaMethod[] add)

Creates an expando meta class with explicit registry behaviour and additional methods.

ExpandoMetaClass(Class theClass, boolean register, MetaMethod[] add)

Creates an expando meta class with optional global registration and additional initial methods.

ExpandoMetaClass(Class theClass, MetaMethod[] add)

Creates an unregistered expando meta class with additional initial methods.
Method Summary

Modifier and Type

Method

Description

boolean

addMixinClass(MixinInMetaClass mixin)

void

addMixinClass$$bridge(MixinInMetaClass mixin)

Deprecated.
use addMixinClass(MixinInMetaClass)

Object

castToMixedType(Object obj, Class type)

Returns the mixed-in view of an object for the requested mixin type.

protected void

checkInitalised()

checks if the initialisation of the class id complete.

CallSite

createConstructorSite(CallSite site, Object[] args)

Create a CallSite

CallSite

createPogoCallCurrentSite(CallSite site, Class sender, String name, Object[] args)

Creates a call site for current-scope POGO dispatch that honours expando invokeMethod.

CallSite

createPogoCallSite(CallSite site, Object[] args)

Create a CallSite

CallSite

createPojoCallSite(CallSite site, Object receiver, Object[] args)

Create a CallSite

CallSite

createStaticSite(CallSite site, Object[] args)

Create a CallSite

ExpandoMetaClass

define(Closure closure)

Executes the expando definition DSL against this meta class.

static void

disableGlobally()

Call to disable the global use of ExpandoMetaClass

static void

enableGlobally()

Call to enable global use of ExpandoMetaClass within the registry.

MetaMethod

findMixinMethod(String methodName, Class[] arguments)

Searches for a matching mixin method.

List<MetaMethod>

getExpandoMethods()

Returns a list of expando MetaMethod instances added to this ExpandoMetaClass

Collection<MetaProperty>

getExpandoProperties()

Returns a list of MetaBeanProperty instances added to this ExpandoMetaClass

Collection

getExpandoSubclassMethods()

Returns the subclass-scoped expando methods registered on this meta class.

Class

getJavaClass()

MetaClass

getMetaClass()

Returns the metaclass for a given class.

MetaProperty

getMetaProperty(String name)

Looks up an existing MetaProperty by name

List<MetaMethod>

getMethods()

Overrides the behavior of parent getMethods() method to make MetaClass aware of added Expando methods

List<MetaProperty>

getProperties()

Returns the available properties for this type.

Object

getProperty(Class sender, Object object, String name, boolean useSuper, boolean fromInsideClass)

Overrides default implementation just in case getProperty method has been overridden by ExpandoMetaClass

Object

getProperty(Object object, String name)

Overrides default implementation just in case getProperty method has been overridden by ExpandoMetaClass

Object

getProperty(String property)

Retrieves a property value.

String

getPropertyForSetter(String setterName)

Returns a property name equivalent for the given setter name or null if it is not a getter

protected Object

getSubclassMetaMethods(String methodName)

Returns subclass-scoped meta methods contributed by specialized meta classes.

boolean

hasCustomStaticInvokeMethod()

indicates is the metaclass method invocation for static methods is done through a custom invoker object.

boolean

hasMetaMethod(String name, Class[] args)

Checks whether a MetaMethod for the given name and arguments exists

boolean

hasMetaProperty(String name)

Returns true if the MetaClass has the given property

void

initialize()

Complete the initialisation process.

Object

invokeConstructor(Object[] arguments)

Invokes a constructor for the given arguments.

Object

invokeMethod(Class sender, Object object, String methodName, Object[] originalArguments, boolean isCallToSuper, boolean fromInsideClass)

Overrides default implementation just in case invokeMethod has been overridden by ExpandoMetaClass

Object

invokeMethod(String name, Object args)

Invokes the given method.

Object

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

Overrides default implementation just in case a static invoke method has been set on ExpandoMetaClass

protected boolean

isInitialized()

Checks if the metaclass is initialized.

boolean

isModified()

Returns whether this MetaClassImpl has been modified.

boolean

isSetter(String name, CachedClass[] args)

Determines whether the supplied method signature represents a Groovy bean setter.

static boolean

isValidExpandoProperty(String property)

Checks whether a property name is available for the expando DSL.

protected void

onGetPropertyFoundInHierarchy(MetaMethod method)

Callback invoked when a getProperty implementation is discovered.

protected void

onInvokeMethodFoundInHierarchy(MetaMethod method)

Callback invoked when an invokeMethod implementation is discovered.

protected void

onSetPropertyFoundInHierarchy(MetaMethod method)

Callback invoked when a setProperty implementation is discovered.

protected void

onSuperMethodFoundInHierarchy(MetaMethod method)

Callback invoked when a super-class method is discovered during initialization.

protected void

onSuperPropertyFoundInHierarchy(MetaBeanProperty property)

Callback invoked when a super-class bean property is discovered during initialization.

protected void

performOperationOnMetaClass(Runnable runner)

Performs a mutating expando operation while coordinating initialization state and locks.

void

refreshInheritedMethods(Set modifiedSuperExpandos)

Called from ExpandoMetaClassCreationHandle in the registry if it exists to set up inheritance handling

void

registerBeanProperty(String property, Object newValue)

Registers a new bean property.

void

registerInstanceMethod(MetaMethod metaMethod)

Registers a new instance method.

void

registerInstanceMethod(String name, Closure closure)

Registers a new instance method.

protected void

registerStaticMethod(String name, Closure callable)

Registers a new static expando method using the closure's declared parameter types.

protected void

registerStaticMethod(String name, Closure callable, Class[] paramTypes)

Registers a new static method for the given method name and closure on this MetaClass

void

registerSubclassInstanceMethod(MetaMethod metaMethod)

Registers a subclass-scoped meta method.

void

registerSubclassInstanceMethod(String name, Class klazz, Closure closure)

Registers an instance method contribution that only applies to the supplied subclass.

MetaMethod

retrieveConstructor(Object[] args)

This is a helper method which is used only by indy.

protected void

setInitialized(boolean b)

Updates the initialization flag for this meta class.

void

setMetaClass(MetaClass metaClass)

Allows the MetaClass to be replaced with a derived implementation.

void

setProperty(Class sender, Object object, String name, Object newValue, boolean useSuper, boolean fromInsideClass)

Overrides default implementation just in case setProperty method has been overridden by ExpandoMetaClass

void

setProperty(String property, Object newValue)

Sets the given property to the new value.

Methods inherited from class groovy.lang.MetaClassImpl
addMetaBeanProperty, addMetaMethod, addMetaMethodToIndex, addNewInstanceMethod, addNewStaticMethod, applyPropertyDescriptors, checkIfGroovyObjectMethod, chooseMethod, clearInvocationCaches, createErrorMessageForAmbiguity, createPogoCallCurrentSite, createTransformMetaMethod, doChooseMostSpecificParams, dropMethodCache, dropStaticMethodCache, findMethodInClassHierarchy, findOwnMethod, findPropertyInClassHierarchy, getAdditionalMetaMethods, getAttribute, getAttribute, getAttribute, getClassInfo, getClassNode, getEffectiveGetMetaProperty, getMetaMethod, getMetaMethods, getMethodWithCaching, getMethodWithoutCaching, getNonClosureOuter, getRegistry, getStaticMetaMethod, getSuperClasses, getTheCachedClass, getTheClass, getVersion, handleMatches, hasCustomInvokeMethod, hasProperty, incVersion, invokeMethod, invokeMethod, invokeMissingMethod, invokeMissingProperty, invokeStaticMissingProperty, isGroovyObject, isPermissivePropertyAccess, onMixinMethodFound, pickMethod, reinitialize, respondsTo, respondsTo, retrieveConstructor, retrieveStaticMethod, selectConstructorAndTransformArguments, setAttribute, setAttribute, setPermissivePropertyAccess, setProperties, setProperty, toString

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Details
- CONSTRUCTOR
  
  public static final String CONSTRUCTOR
  
  Pseudo-property used by the expando DSL to define constructors.
  See Also:
  
  Constant Field Values
- STATIC_QUALIFIER
  
  public static final String STATIC_QUALIFIER
  
  Pseudo-property used by the expando DSL to define static members.
  See Also:
  
  Constant Field Values
- inRegistry
  
  public boolean inRegistry
  
  Indicates whether this expando meta class is registered in the global registry.
Constructor Details
- ExpandoMetaClass
  
  public ExpandoMetaClass(Class theClass, boolean register, boolean allowChangesAfterInit, MetaMethod[] add)
  
  Creates an expando meta class with explicit registry behaviour and additional methods.
  
  Parameters:
  
  theClass - the enhanced class
  
  register - whether the meta class should be registered globally
  
  allowChangesAfterInit - whether mutation is allowed after initialization
  
  add - additional meta methods to seed the meta class with
- ExpandoMetaClass
  
  public ExpandoMetaClass(MetaClassRegistry registry, Class theClass, boolean register, boolean allowChangesAfterInit, MetaMethod[] add)
  
  Creates an expando meta class bound to a specific registry.
  
  Parameters:
  
  registry - the meta class registry to work with
  
  theClass - the enhanced class
  
  register - whether the meta class should be registered globally
  
  allowChangesAfterInit - whether mutation is allowed after initialization
  
  add - additional meta methods to seed the meta class with
- ExpandoMetaClass
  
  public ExpandoMetaClass(Class theClass)
  
  Constructs a new ExpandoMetaClass instance for the given class
  
  Parameters:
  
  theClass - The class that the MetaClass applies to
- ExpandoMetaClass
  
  public ExpandoMetaClass(Class theClass, MetaMethod[] add)
  
  Creates an unregistered expando meta class with additional initial methods.
  
  Parameters:
  
  theClass - the enhanced class
  
  add - additional meta methods to seed the meta class with
- ExpandoMetaClass
  
  public ExpandoMetaClass(Class theClass, boolean register)
  
  Constructs a new ExpandoMetaClass instance for the given class optionally placing the MetaClass in the MetaClassRegistry automatically
  
  Parameters:
  
  theClass - The class that the MetaClass applies to
  
  register - True if the MetaClass should be registered inside the MetaClassRegistry. This defaults to true and ExpandoMetaClass will affect all instances if changed
- ExpandoMetaClass
  
  public ExpandoMetaClass(Class theClass, boolean register, MetaMethod[] add)
  
  Creates an expando meta class with optional global registration and additional initial methods.
  
  Parameters:
  
  theClass - the enhanced class
  
  register - whether the meta class should be registered globally
  
  add - additional meta methods to seed the meta class with
- ExpandoMetaClass
  
  public ExpandoMetaClass(Class theClass, boolean register, boolean allowChangesAfterInit)
  
  Constructs a new ExpandoMetaClass instance for the given class optionally placing the MetaClass in the MetaClassRegistry automatically
  
  Parameters:
  
  theClass - The class that the MetaClass applies to
  
  register - True if the MetaClass should be registered inside the MetaClassRegistry. This defaults to true and ExpandoMetaClass will affect all instances if changed
  
  allowChangesAfterInit - Should the metaclass be modifiable after initialization. Default is false.
Method Details
- findMixinMethod
  
  public MetaMethod findMixinMethod(String methodName, Class[] arguments)
  
  Searches for a matching mixin method.
  
  Overrides:
  
  findMixinMethod in class MetaClassImpl
  
  Parameters:
  
  methodName - the method name
  
  arguments - the parameter types
  
  Returns:
  
  the matching mixin method, or null if none is found
- onInvokeMethodFoundInHierarchy
  
  protected void onInvokeMethodFoundInHierarchy(MetaMethod method)
  
  Callback invoked when an invokeMethod implementation is discovered.
  
  Overrides:
  
  onInvokeMethodFoundInHierarchy in class MetaClassImpl
  
  Parameters:
  
  method - the discovered handler
- onSuperMethodFoundInHierarchy
  
  protected void onSuperMethodFoundInHierarchy(MetaMethod method)
  
  Callback invoked when a super-class method is discovered during initialization.
  
  Overrides:
  
  onSuperMethodFoundInHierarchy in class MetaClassImpl
  
  Parameters:
  
  method - the inherited method
- onSuperPropertyFoundInHierarchy
  
  protected void onSuperPropertyFoundInHierarchy(MetaBeanProperty property)
  
  Callback invoked when a super-class bean property is discovered during initialization.
  
  Overrides:
  
  onSuperPropertyFoundInHierarchy in class MetaClassImpl
  
  Parameters:
  
  property - the inherited property
- onSetPropertyFoundInHierarchy
  
  protected void onSetPropertyFoundInHierarchy(MetaMethod method)
  
  Callback invoked when a setProperty implementation is discovered.
  
  Overrides:
  
  onSetPropertyFoundInHierarchy in class MetaClassImpl
  
  Parameters:
  
  method - the discovered handler
- onGetPropertyFoundInHierarchy
  
  protected void onGetPropertyFoundInHierarchy(MetaMethod method)
  
  Callback invoked when a getProperty implementation is discovered.
  
  Overrides:
  
  onGetPropertyFoundInHierarchy in class MetaClassImpl
  
  Parameters:
  
  method - the discovered handler
- isModified
  
  public boolean isModified()
  
  Returns whether this MetaClassImpl has been modified. Since MetaClassImpl is not designed for modification this method always returns false
  
  Specified by:
  
  isModified in interface MutableMetaClass
  
  Overrides:
  
  isModified in class MetaClassImpl
  
  Returns:
  
  false
- registerSubclassInstanceMethod
  
  public void registerSubclassInstanceMethod(String name, Class klazz, Closure closure)
  
  Registers an instance method contribution that only applies to the supplied subclass.
  
  Parameters:
  
  name - the method name
  
  klazz - the subclass receiving the method
  
  closure - the implementation closure
- registerSubclassInstanceMethod
  
  public void registerSubclassInstanceMethod(MetaMethod metaMethod)
  
  Registers a subclass-scoped meta method.
  
  Parameters:
  
  metaMethod - the method to register
- addMixinClass$$bridge
  
  @Deprecated public void addMixinClass$$bridge(MixinInMetaClass mixin)
  
  Deprecated.
  use addMixinClass(MixinInMetaClass)
  
  Legacy bridge retained for binary compatibility with earlier expando mixin APIs.
  
  Parameters:
  
  mixin - the mixin definition to add
- addMixinClass
  
  public boolean addMixinClass(MixinInMetaClass mixin)
  
  Since:
  
  6.0.0
- castToMixedType
  
  public Object castToMixedType(Object obj, Class type)
  
  Returns the mixed-in view of an object for the requested mixin type.
  
  Parameters:
  
  obj - the receiver object
  
  type - the requested mixin type
  
  Returns:
  
  the mixin instance, or null if the type is not mixed in
- enableGlobally
  
  public static void enableGlobally()
  
  Call to enable global use of ExpandoMetaClass within the registry. This has the advantage that inheritance will function correctly and metaclass modifications will also apply to existing objects, but has a higher memory usage on the JVM than normal Groovy
- disableGlobally
  
  public static void disableGlobally()
  
  Call to disable the global use of ExpandoMetaClass
- initialize
  
  public void initialize()
  
  Complete the initialisation process. After this method is called no methods should be added to the metaclass. 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
- isInitialized
  
  protected boolean isInitialized()
  
  Checks if the metaclass is initialized.
  Overrides:
  
  isInitialized in class MetaClassImpl
  
  Returns:
  
  true once initialization completed
  
  See Also:
  
  MetaClassImpl.isInitialized()
- setInitialized
  
  protected void setInitialized(boolean b)
  
  Updates the initialization flag for this meta class.
  
  Overrides:
  
  setInitialized in class MetaClassImpl
  
  Parameters:
  
  b - the new initialization state
- invokeConstructor
  
  public Object invokeConstructor(Object[] arguments)
  
  Invokes a constructor for the given arguments. The MetaClass will attempt to pick the best argument which matches the types of the objects passed within the arguments array
  
  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
- getMetaClass
  
  public MetaClass getMetaClass()
  
  Returns the metaclass for a given class.
  
  Specified by:
  
  getMetaClass in interface GroovyObject
  
  Returns:
  
  the metaClass of this instance
- getProperty
  
  public Object getProperty(String property)
  
  Retrieves a property value.
  
  Specified by:
  
  getProperty in interface GroovyObject
  
  Parameters:
  
  property - the name of the property of interest
  
  Returns:
  
  the given property
- isValidExpandoProperty
  
  public static boolean isValidExpandoProperty(String property)
  
  Checks whether a property name is available for the expando DSL.
  
  Parameters:
  
  property - the property name to test
  
  Returns:
  
  true if the name can be used by the expando DSL
- invokeMethod
  
  public Object invokeMethod(String name, Object args)
  
  Invokes the given method.
  
  Specified by:
  
  invokeMethod in interface GroovyObject
  
  Parameters:
  
  name - the name of the method to call
  
  args - the arguments to use for the method call
  
  Returns:
  
  the result of invoking the method
- setMetaClass
  
  public void setMetaClass(MetaClass metaClass)
  
  Allows the MetaClass to be replaced with a derived implementation.
  
  Specified by:
  
  setMetaClass in interface GroovyObject
  
  Parameters:
  
  metaClass - the new metaclass
- setProperty
  
  public void setProperty(String property, Object newValue)
  
  Sets the given property to the new value.
  
  Specified by:
  
  setProperty in interface GroovyObject
  
  Parameters:
  
  property - the name of the property of interest
  
  newValue - the new value for the property
- define
  
  public ExpandoMetaClass define(@ClosureParams(value=SimpleType.class,options="java.lang.Object") @DelegatesTo(value=groovy.lang.ExpandoMetaClass.DefiningClosure.class,strategy=3) Closure closure)
  
  Executes the expando definition DSL against this meta class.
  
  Parameters:
  
  closure - the definition closure
  
  Returns:
  
  this meta class
- performOperationOnMetaClass
  
  protected void performOperationOnMetaClass(Runnable runner)
  
  Performs a mutating expando operation while coordinating initialization state and locks.
  
  Parameters:
  
  runner - the operation to execute
- checkInitalised
  
  protected void checkInitalised()
  
  checks if the initialisation of the class id complete. This method should be called as a form of assert, it is no way to test if there is still initialisation work to be done. Such logic must be implemented in a different way.
  
  Overrides:
  
  checkInitalised in class MetaClassImpl
- registerBeanProperty
  
  public void registerBeanProperty(String property, Object newValue)
  
  Registers a new bean property.
  
  Parameters:
  
  property - the property name
  
  newValue - the properties initial value
- registerInstanceMethod
  
  public void registerInstanceMethod(String name, Closure closure)
  
  Registers a new instance method.
  
  Parameters:
  
  name - the method name or "constructor" for a constructor
  
  closure - the implementation
- registerInstanceMethod
  
  public void registerInstanceMethod(MetaMethod metaMethod)
  
  Registers a new instance method.
- getMethods
  
  public List<MetaMethod> getMethods()
  
  Overrides the behavior of parent getMethods() method to make MetaClass aware of added Expando methods
  Specified by:
  
  getMethods in interface MetaClass
  
  Specified by:
  
  getMethods in interface MetaObjectProtocol
  
  Overrides:
  
  getMethods in class MetaClassImpl
  
  Returns:
  
  A list of MetaMethods
  
  See Also:
  
  MetaObjectProtocol.getMethods()
- getProperties
  
  public List<MetaProperty> getProperties()
  
  Returns the available properties for this type.
  Specified by:
  
  getProperties in interface MetaClass
  
  Specified by:
  
  getProperties in interface MetaObjectProtocol
  
  Overrides:
  
  getProperties in class MetaClassImpl
  
  Returns:
  
  a list of MetaProperty objects
  
  See Also:
  
  MetaProperty
- registerStaticMethod
  
  protected void registerStaticMethod(String name, Closure callable)
  
  Registers a new static expando method using the closure's declared parameter types.
  
  Parameters:
  
  name - the method name
  
  callable - the implementation closure
- registerStaticMethod
  
  protected void registerStaticMethod(String name, Closure callable, Class[] paramTypes)
  
  Registers a new static method for the given method name and closure on this MetaClass
  
  Parameters:
  
  name - The method name
  
  callable - The callable Closure
- getSubclassMetaMethods
  
  protected Object getSubclassMetaMethods(String methodName)
  
  Returns subclass-scoped meta methods contributed by specialized meta classes.
  
  Overrides:
  
  getSubclassMetaMethods in class MetaClassImpl
  
  Parameters:
  
  methodName - the method name
  
  Returns:
  
  subclass methods for the name, or null if none are registered
- getJavaClass
  
  public Class getJavaClass()
  
  Returns:
  
  The Java class enhanced by this MetaClass
- refreshInheritedMethods
  
  public void refreshInheritedMethods(Set modifiedSuperExpandos)
  
  Called from ExpandoMetaClassCreationHandle in the registry if it exists to set up inheritance handling
  
  Parameters:
  
  modifiedSuperExpandos - A list of modified super ExpandoMetaClass
- getExpandoMethods
  
  public List<MetaMethod> getExpandoMethods()
  
  Returns a list of expando MetaMethod instances added to this ExpandoMetaClass
  
  Returns:
  
  the expandoMethods
- getExpandoSubclassMethods
  
  public Collection getExpandoSubclassMethods()
  
  Returns the subclass-scoped expando methods registered on this meta class.
  
  Returns:
  
  an unmodifiable view of the registered subclass method entries
- getExpandoProperties
  
  public Collection<MetaProperty> getExpandoProperties()
  
  Returns a list of MetaBeanProperty instances added to this ExpandoMetaClass
  
  Returns:
  
  the expandoProperties
- invokeMethod
  
  public Object invokeMethod(Class sender, Object object, String methodName, Object[] originalArguments, boolean isCallToSuper, boolean fromInsideClass)
  
  Overrides default implementation just in case invokeMethod has been overridden by ExpandoMetaClass
  Specified by:
  
  invokeMethod in interface MetaClass
  
  Overrides:
  
  invokeMethod in class MetaClassImpl
  
  Parameters:
  
  sender - The java.lang.Class instance that invoked the method
  
  object - The object which the method was invoked on
  
  methodName - The name of the method
  
  originalArguments - The arguments to the method
  
  isCallToSuper - Whether the method is a call to a super class method
  
  fromInsideClass - Whether the call was invoked from the inside or the outside of the class
  
  Returns:
  
  The return value of the method.
  
  See Also:
  
  MetaClassImpl.invokeMethod(Class, Object, String, Object[], boolean, boolean)
- invokeStaticMethod
  
  public Object invokeStaticMethod(Object object, String methodName, Object[] arguments)
  
  Overrides default implementation just in case a static invoke method has been set on ExpandoMetaClass
  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:
  
  MetaClassImpl.invokeStaticMethod(Object, String, Object[])
- getProperty
  
  public Object getProperty(Class sender, Object object, String name, boolean useSuper, boolean fromInsideClass)
  
  Overrides default implementation just in case getProperty method has been overridden by ExpandoMetaClass
  Specified by:
  
  getProperty in interface MetaClass
  
  Overrides:
  
  getProperty in class MetaClassImpl
  
  Parameters:
  
  sender - The java.lang.Class instance that requested the property
  
  object - The Object which the property is being retrieved from
  
  name - The name of the property
  
  useSuper - Whether the call is to a super class property
  
  fromInsideClass - ??
  
  Returns:
  
  The property's value.
  
  See Also:
  
  MetaClassImpl.getProperty(Class, Object, String, boolean, boolean)
- getProperty
  
  public Object getProperty(Object object, String name)
  
  Overrides default implementation just in case getProperty method has been overridden by ExpandoMetaClass
  Specified by:
  
  getProperty in interface MetaObjectProtocol
  
  Overrides:
  
  getProperty in class MetaClassImpl
  
  Parameters:
  
  object - The Object which the property is being retrieved from
  
  name - The name of the property
  
  Returns:
  
  The properties value
  
  See Also:
  
  MetaClassImpl.getProperty(Object, String)
- setProperty
  
  public void setProperty(Class sender, Object object, String name, Object newValue, boolean useSuper, boolean fromInsideClass)
  
  Overrides default implementation just in case setProperty method has been overridden by ExpandoMetaClass
  Specified by:
  
  setProperty in interface MetaClass
  
  Overrides:
  
  setProperty in class MetaClassImpl
  
  Parameters:
  
  sender - The java.lang.Class instance that is mutating the property
  
  object - The Object which the property is being set on
  
  name - The name of the property
  
  newValue - The new value of the property to set
  
  useSuper - Whether the call is to a super class property
  
  fromInsideClass - Whether the call was invoked from the inside or the outside of the class.
  
  See Also:
  
  MetaClassImpl.setProperty(Class, Object, String, Object, boolean, boolean)
- getMetaProperty
  
  public MetaProperty getMetaProperty(String name)
  
  Looks up an existing MetaProperty by name
  Specified by:
  
  getMetaProperty in interface MetaObjectProtocol
  
  Overrides:
  
  getMetaProperty in class MetaClassImpl
  
  Parameters:
  
  name - The name of the MetaProperty
  
  Returns:
  
  The MetaProperty or null if it doesn't exist
  
  See Also:
  
  MetaObjectProtocol.getMetaProperty(String)
- hasMetaProperty
  
  public boolean hasMetaProperty(String name)
  
  Returns true if the MetaClass has the given property
  
  Parameters:
  
  name - The name of the MetaProperty
  
  Returns:
  
  True it exists as a MetaProperty
- hasMetaMethod
  
  public boolean hasMetaMethod(String name, Class[] args)
  
  Checks whether a MetaMethod for the given name and arguments exists
  
  Parameters:
  
  name - The name of the MetaMethod
  
  args - The arguments to the meta method
  
  Returns:
  
  True if the method exists otherwise null
- getPropertyForSetter
  
  public String getPropertyForSetter(String setterName)
  
  Returns a property name equivalent for the given setter name or null if it is not a getter
  
  Parameters:
  
  setterName - The setter name
  
  Returns:
  
  The property name equivalent
- isSetter
  
  public boolean isSetter(String name, CachedClass[] args)
  
  Determines whether the supplied method signature represents a Groovy bean setter.
  
  Parameters:
  
  name - the candidate method name
  
  args - the candidate parameter types
  
  Returns:
  
  true if the signature represents a setter
- createPojoCallSite
  
  public CallSite createPojoCallSite(CallSite site, Object receiver, Object[] args)
  
  Create a CallSite
  
  Overrides:
  
  createPojoCallSite in class MetaClassImpl
- createStaticSite
  
  public CallSite createStaticSite(CallSite site, Object[] args)
  
  Create a CallSite
  
  Overrides:
  
  createStaticSite in class MetaClassImpl
- hasCustomStaticInvokeMethod
  
  public boolean hasCustomStaticInvokeMethod()
  
  indicates is the metaclass method invocation for static methods is done through a custom invoker object.
  
  Overrides:
  
  hasCustomStaticInvokeMethod in class MetaClassImpl
  
  Returns:
  
  true - if the method invocation is not done by the metaclass itself
- createPogoCallSite
  
  public CallSite createPogoCallSite(CallSite site, Object[] args)
  
  Create a CallSite
  
  Overrides:
  
  createPogoCallSite in class MetaClassImpl
- createPogoCallCurrentSite
  
  public CallSite createPogoCallCurrentSite(CallSite site, Class sender, String name, Object[] args)
  
  Creates a call site for current-scope POGO dispatch that honours expando invokeMethod.
  
  Parameters:
  
  site - the original call site
  
  sender - the calling class
  
  name - the method name being invoked
  
  args - the invocation arguments
  
  Returns:
  
  the adapted call site
- retrieveConstructor
  
  public MetaMethod retrieveConstructor(Object[] args)
  
  This is a helper method which is used only by indy. It is for internal use.
  
  Overrides:
  
  retrieveConstructor in class MetaClassImpl
- createConstructorSite
  
  public CallSite createConstructorSite(CallSite site, Object[] args)
  
  Create a CallSite
  
  Overrides:
  
  createConstructorSite in class MetaClassImpl

Class ExpandoMetaClass

Nested Class Summary

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

Field Summary

Fields inherited from class groovy.lang.MetaClassImpl

Constructor Summary

Method Summary

Methods inherited from class groovy.lang.MetaClassImpl

Methods inherited from class java.lang.Object

Field Details

CONSTRUCTOR

STATIC_QUALIFIER

inRegistry

Constructor Details

ExpandoMetaClass

ExpandoMetaClass

ExpandoMetaClass

ExpandoMetaClass

ExpandoMetaClass

ExpandoMetaClass

ExpandoMetaClass

Method Details

findMixinMethod

onInvokeMethodFoundInHierarchy

onSuperMethodFoundInHierarchy

onSuperPropertyFoundInHierarchy

onSetPropertyFoundInHierarchy

onGetPropertyFoundInHierarchy

isModified

registerSubclassInstanceMethod

registerSubclassInstanceMethod

addMixinClass$$bridge

addMixinClass

castToMixedType

enableGlobally

disableGlobally

initialize

isInitialized

setInitialized

invokeConstructor

getMetaClass

getProperty

isValidExpandoProperty

invokeMethod

setMetaClass

setProperty

define

performOperationOnMetaClass

checkInitalised

registerBeanProperty

registerInstanceMethod

registerInstanceMethod

getMethods

getProperties

registerStaticMethod

registerStaticMethod

getSubclassMetaMethods

getJavaClass

refreshInheritedMethods

getExpandoMethods

getExpandoSubclassMethods

getExpandoProperties

invokeMethod

invokeStaticMethod

getProperty

getProperty

setProperty

getMetaProperty

hasMetaProperty

hasMetaMethod

getPropertyForSetter

isSetter

createPojoCallSite

createStaticSite

hasCustomStaticInvokeMethod

createPogoCallSite

createPogoCallCurrentSite

retrieveConstructor

createConstructorSite