public interface MetaClass extends MetaObjectProtocol
A MetaClass within Groovy defines the behaviour of any given Groovy or Java class. The MetaClass interface defines two parts. The client API, which is defined via the extend MetaObjectProtocol interface and the contract with the Groovy runtime system. In general the compiler and Groovy runtime engine interact with methods on this class whilst MetaClass clients interact with the method defined by the MetaObjectProtocol interface
| Type Params | Return Type | Name and description |
|---|---|---|
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public Object |
getAttribute(Class sender, Object receiver, String messageName, boolean useSuper)Retrieves the value of an attribute (field). |
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public ClassNode |
getClassNode()Obtains a reference to the original AST for the MetaClass if it is available at runtime |
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public List<MetaMethod> |
getMetaMethods()Retrieves a list of MetaMethods held by this class. |
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public List<MetaMethod> |
getMethods()Retrieves a list of MetaMethods held by the class. |
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public List<MetaProperty> |
getProperties()Retrieves a list of MetaProperty instances that the MetaClass has |
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public Object |
getProperty(Class sender, Object receiver, String property, boolean isCallToSuper, boolean fromInsideClass) |
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public void |
initialize()Complete the initialisation process. |
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public Object |
invokeMethod(Class sender, Object receiver, String methodName, Object[] arguments, boolean isCallToSuper, boolean fromInsideClass) |
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public Object |
invokeMissingMethod(Object instance, String methodName, Object[] arguments) |
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public Object |
invokeMissingProperty(Object instance, String propertyName, Object optionalValue, boolean isGetter)Invokes the propertyMissing method otherwise throws a MissingPropertyException |
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public MetaMethod |
pickMethod(String methodName, Class[] arguments)Selects a method by name and argument classes. |
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public int |
selectConstructorAndTransformArguments(int numberOfConstructors, Object[] arguments)Internal method to support Groovy runtime. |
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public void |
setAttribute(Class sender, Object receiver, String messageName, Object messageValue, boolean useSuper, boolean fromInsideClass)Sets the value of an attribute (field). |
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public void |
setProperty(Class sender, Object receiver, String property, Object value, boolean isCallToSuper, boolean fromInsideClass) |
| Methods inherited from class | Name |
|---|---|
interface MetaObjectProtocol |
getAttribute, getMetaMethod, getMetaProperty, getMethods, getProperties, getProperty, getStaticMetaMethod, getTheClass, hasProperty, invokeConstructor, invokeMethod, invokeMethod, invokeStaticMethod, respondsTo, respondsTo, setAttribute, setProperty |
Retrieves the value of an attribute (field). This method is to support the Groovy runtime and not for general client API usage.
sender - The class of the object that requested the attributereceiver - The instancemessageName - The name of the attributeuseSuper - Whether to look-up on the super class or notObtains a reference to the original AST for the MetaClass if it is available at runtime
Retrieves a list of MetaMethods held by this class. This list includes MetaMethods added by groovy.lang.ExpandoMetaClass.
Retrieves a list of MetaMethods held by the class. This list does not include MetaMethods added by groovy.lang.ExpandoMetaClass.
Retrieves a list of MetaProperty instances that the MetaClass has
Retrieves a property on the given receiver for the specified arguments. The sender is the class that is requesting the property from the object. The MetaClass will attempt to establish the method to invoke based on the name and arguments provided.
The isCallToSuper and fromInsideClass help the Groovy runtime perform optimisations on the call to go directly to the super class if necessary
sender - The java.lang.Class instance that requested the propertyreceiver - The Object which the property is being retrieved fromproperty - The name of the propertyisCallToSuper - Whether the call is to a super class propertyfromInsideClass - ??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.
Invokes a method on the given receiver for the specified arguments. The sender is the class that invoked the method on the object. The MetaClass will attempt to establish the method to invoke based on the name and arguments provided.
The isCallToSuper and fromInsideClass help the Groovy runtime perform optimisations on the call to go directly to the super class if necessary
sender - The java.lang.Class instance that invoked the methodreceiver - The object which the method was invoked onmethodName - The name of the methodarguments - The arguments to the methodisCallToSuper - Whether the method is a call to a super class methodfromInsideClass - Whether the call was invoked from the inside or the outside of the class
Attempts to invoke the methodMissing method otherwise throws a MissingMethodException
instance - The instance to invoke methodMissing onmethodName - The name of the methodarguments - The arguments to the methodInvokes the propertyMissing method otherwise throws a MissingPropertyException
instance - The instance of the classpropertyName - The name of the propertyoptionalValue - The value of the property which could be null in the case of a getterisGetter - Whether the missing property event was the result of a getter or a setterSelects a method by name and argument classes. This method does not search for an exact match, it searches for a compatible method. For this the method selection mechanism is used as provided by the implementation of this MetaClass. pickMethod may or may not be used during the method selection process when invoking a method. There is no warranty for that.
methodName - the name of the method to pickarguments - the method argumentsInternal method to support Groovy runtime. Not for client usage.
numberOfConstructors - The number of constructorsarguments - The argumentsSets the value of an attribute (field). This method is to support the Groovy runtime and not for general client API usage.
sender - The class of the object that requested the attributereceiver - The instancemessageName - The name of the attributemessageValue - The value of the attributeuseSuper - Whether to look-up on the super class or notfromInsideClass - Whether the call happened from the inside or the outside of a class
Sets a property on the given receiver for the specified arguments. The sender is the class that is setting the property from the object. The MetaClass will attempt to establish the method to invoke based on the name and arguments provided.
The isCallToSuper and fromInsideClass help the Groovy runtime perform optimisations on the call to go directly to the super class if necessary
sender - The java.lang.Class instance that is mutating the propertyreceiver - The Object which the property is being set onproperty - The name of the propertyvalue - The new value of the property to setisCallToSuper - Whether the call is to a super class propertyfromInsideClass - Whether the call was invoked from the inside or the outside of the class