MetaObjectProtocol (groovy 3.0.4 API)

```
public interface MetaObjectProtocol
```
An interface that defines the API usable by clients of Groovy's Meta Object Protocol (MOP). These methods are implemented by the reference implementation of the MetaClass interface.
See Also:
MetaClassImpl

Methods Summary

Methods
Type Params	Return Type	Name and description
	`Object`	`getAttribute(Object object, String attribute)` Retrieves an attribute of an instance of the class returned by the getTheClass() method.
	`MetaMethod`	`getMetaMethod(String name, Object[] args)` Retrieves an instance MetaMethod for the given name and argument values, using the types of the argument values to establish the chosen MetaMethod
	`MetaProperty`	`getMetaProperty(String name)` Returns a MetaProperty for the given name or null if it doesn't exist
	`List<MetaMethod>`	`getMethods()` Obtain a list of all the meta methods available on this meta class
	`List<MetaProperty>`	`getProperties()` Obtain a list of all meta properties available on this meta class
	`Object`	`getProperty(Object object, String property)` Retrieves a property of an instance of the class returned by the getTheClass() method.
	`MetaMethod`	`getStaticMetaMethod(String name, Object[] args)` Retrieves a static MetaMethod for the given name and argument values, using the types of the arguments to establish the chosen MetaMethod
	`Class`	`getTheClass()` Retrieves that Java Class that the attached Meta behaviours apply to
	`MetaProperty`	`hasProperty(Object obj, String name)`
	`Object`	`invokeConstructor(Object[] arguments)` Invokes a constructor for the given arguments.
	`Object`	`invokeMethod(Object object, String methodName, Object[] arguments)` Invokes a method on the given Object with the given name and arguments.
	`Object`	`invokeMethod(Object object, String methodName, Object arguments)` Invokes a method on the given object, with the given name and single argument.
	`Object`	`invokeStaticMethod(Object object, String methodName, Object[] arguments)` Invokes a static method on the given Object with the given name and arguments.
	`List<MetaMethod>`	`respondsTo(Object obj, String name, Object[] argTypes)`
	`List<MetaMethod>`	`respondsTo(Object obj, String name)`
	`void`	`setAttribute(Object object, String attribute, Object newValue)` Sets an attribute of an instance of the class returned by the getTheClass() method.
	`void`	`setProperty(Object object, String property, Object newValue)` Sets a property of an instance of the class returned by the getTheClass() method.

- Method Detail
  - public Object getAttribute(Object object, String attribute)
    
    Retrieves an attribute of an instance of the class returned by the getTheClass() method.
    What this means is largely down to the MetaClass implementation, however the default case would result in attempt to read a field of the instance.
    See Also:
    MetaClassImpl
    Parameters:
    object - An instance of the class returned by the getTheClass() method
    attribute - The name of the attribute to retrieve the value for
    Returns:
    The attribute value
  - public MetaMethod getMetaMethod(String name, Object[] args)
    
    Retrieves an instance MetaMethod for the given name and argument values, using the types of the argument values to establish the chosen MetaMethod
    Parameters:
    name - The name of the MetaMethod
    args - Array containing - 1) the argument values (using which their types are then inferred), or 2) the corresponding argument types
    Returns:
    A MetaMethod or null if it doesn't exist
  - public MetaProperty getMetaProperty(String name)
    
    Returns a MetaProperty for the given name or null if it doesn't exist
    Parameters:
    name - The name of the MetaProperty
    Returns:
    A MetaProperty or null
  - public List<MetaMethod> getMethods()
    
    Obtain a list of all the meta methods available on this meta class
    See Also:
    MetaMethod
    Returns:
    A list of MetaMethod instances
  - public List<MetaProperty> getProperties()
    
    Obtain a list of all meta properties available on this meta class
    See Also:
    MetaProperty
    Returns:
    A list of MetaProperty instances
  - public Object getProperty(Object object, String property)
    
    Retrieves a property of an instance of the class returned by the getTheClass() method.
    What this means is largely down to the MetaClass implementation, however the default case would result in an attempt to invoke a JavaBean getter, or if no such getter exists a public field of the instance.
    See Also:
    MetaClassImpl
    Parameters:
    object - An instance of the class returned by the getTheClass() method
    property - The name of the property to retrieve the value for
    Returns:
    The properties value
  - public MetaMethod getStaticMetaMethod(String name, Object[] args)
    
    Retrieves a static MetaMethod for the given name and argument values, using the types of the arguments to establish the chosen MetaMethod
    Parameters:
    name - The name of the MetaMethod
    args - The argument types
    Returns:
    A MetaMethod or null if it doesn't exist
  - public Class getTheClass()
    
    Retrieves that Java Class that the attached Meta behaviours apply to
    Returns:
    The java.lang.Class instance
  - public MetaProperty hasProperty(Object obj, String name)
    
    Returns true of the implementing MetaClass has a property of the given name
    Note that this method will only return true for realised properties and does not take into account implementation of getProperty or propertyMissing
    Parameters:
    obj - The object to inspect
    name - The name of the property
    Returns:
    The MetaProperty or null if it doesn't exist
  - 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
    Parameters:
    arguments - The arguments to the constructor
    Returns:
    An instance of the java.lang.Class that this MetaObjectProtocol object applies to
  - public Object invokeMethod(Object object, String methodName, Object[] arguments)
    
    Invokes a method on the given Object with the given name and arguments. The MetaClass will attempt to pick the best method for the given name and arguments. If a method cannot be invoked a MissingMethodException will be thrown.
    See Also:
    MissingMethodException
    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
  - public Object invokeMethod(Object object, String methodName, Object arguments)
    
    Invokes a method on the given object, with the given name and single argument.
    See Also:
    invokeMethod(Object, String, Object[])
    Parameters:
    object - The Object to invoke the method on
    methodName - The name of the method
    arguments - The argument to the method
    Returns:
    The return value of the method which is null if the return type is void
  - public Object invokeStaticMethod(Object object, String methodName, Object[] arguments)
    
    Invokes a static method on the given Object with the given name and arguments.
    The Object can either be an instance of the class that this MetaObjectProtocol instance applies to or the java.lang.Class instance itself. If a method cannot be invoked a MissingMethodException is will be thrown
    See Also:
    MissingMethodException
    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
  - public List<MetaMethod> respondsTo(Object obj, String name, Object[] argTypes)
    
    Returns an object satisfying Groovy truth if the implementing MetaClass responds to a method with the given name and arguments types.
    Note that this method's return value is based on realised methods and does not take into account objects or classes that implement invokeMethod or methodMissing
    This method is "safe" in that it will always return a value and never throw an exception
    Parameters:
    obj - The object to inspect
    name - The name of the method of interest
    argTypes - The argument types to match against
    Returns:
    A List of MetaMethods matching the argument types which will be empty if no matching methods exist
  - public List<MetaMethod> respondsTo(Object obj, String name)
    
    Returns an object satisfying Groovy truth if the implementing MetaClass responds to a method with the given name regardless of arguments. In other words this method will return for foo() and foo(String).
    Note that this method's return value is based on realised methods and does not take into account objects or classes that implement invokeMethod or methodMissing
    This method is "safe" in that it will always return a value and never throw an exception
    Parameters:
    obj - The object to inspect
    name - The name of the method of interest
    Returns:
    A List of MetaMethods which will be empty if no methods with the given name exist
  - public void setAttribute(Object object, String attribute, Object newValue)
    
    Sets an attribute of an instance of the class returned by the getTheClass() method.
    What this means is largely down to the MetaClass implementation, however the default case would result in an attempt to set a field of the instance.
    See Also:
    MetaClassImpl
    Parameters:
    object - An instance of the class returned by the getTheClass() method
    attribute - The name of the attribute to set
    newValue - The new value of the attribute
  - public void setProperty(Object object, String property, Object newValue)
    
    Sets a property of an instance of the class returned by the getTheClass() method.
    What this means is largely down to the MetaClass implementation, however the default case would result in an attempt to invoke a JavaBean setter, or if no such setter exists to set a public field of the instance.
    See Also:
    MetaClassImpl
    Parameters:
    object - An instance of the class returned by the getTheClass() method
    property - The name of the property to set
    newValue - The new value of the property

Summary:
Method

| Detail:
Method

[Java] Interface MetaObjectProtocol

Methods Summary

Method Detail

public Object getAttribute(Object object, String attribute)

public MetaMethod getMetaMethod(String name, Object[] args)

public MetaProperty getMetaProperty(String name)

public List<MetaMethod> getMethods()

public List<MetaProperty> getProperties()

public Object getProperty(Object object, String property)

public MetaMethod getStaticMetaMethod(String name, Object[] args)

public Class getTheClass()

public MetaProperty hasProperty(Object obj, String name)

public Object invokeConstructor(Object[] arguments)

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

public Object invokeMethod(Object object, String methodName, Object arguments)

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

public List<MetaMethod> respondsTo(Object obj, String name, Object[] argTypes)

public List<MetaMethod> respondsTo(Object obj, String name)

public void setAttribute(Object object, String attribute, Object newValue)

public void setProperty(Object object, String property, Object newValue)