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 invocations 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, java.lang.Class theClass, MetaClass adaptee)`

  - ### Method Summary

    All Methods Static Methods Instance Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `MetaClass` | `getAdaptee()` Returns the MetaClass that this adapter adapts
    `static ProxyMetaClass` | `getInstance(java.lang.Class theClass)` convenience factory method for the most usual case.
    `Interceptor` | `getInterceptor()`
    `java.lang.Object` | `getProperty(java.lang.Class aClass, java.lang.Object object, java.lang.String property, boolean b, boolean b1)` Interceptors the call to getProperty if a PropertyAccessInterceptor is available
    `void` | `initialize()` Complete the initialisation process.
    `java.lang.Object` | `invokeConstructor(java.lang.Object[] arguments)` Call invokeConstructor on adaptee with logic like in MetaClass unless we have an Interceptor.
    `java.lang.Object` | `invokeMethod(java.lang.Object object, java.lang.String methodName, java.lang.Object[] arguments)` Call invokeMethod on adaptee with logic like in MetaClass unless we have an Interceptor.
    `java.lang.Object` | `invokeStaticMethod(java.lang.Object object, java.lang.String methodName, java.lang.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(java.lang.Class aClass, java.lang.Object object, java.lang.String property, java.lang.Object newValue, boolean b, boolean b1)` Interceptors the call to a property setter if a PropertyAccessInterceptor is available
    `java.lang.Object` | `use(Closure closure)` Use the ProxyMetaClass for the given Closure.
    `java.lang.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, createErrorMessageForAmbiguity, createPogoCallCurrentSite, createPogoCallSite, createPojoCallSite, createStaticSite, createTransformMetaMethod, doChooseMostSpecificParams, 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, handleMatches, hasCustomInvokeMethod, hasCustomStaticInvokeMethod, 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,
                                java.lang.Class theClass,
                                MetaClass adaptee)

      Parameters:
        `adaptee` - the MetaClass to decorate with interceptability

  - ### Method Detail

    - #### getInstance

          public static ProxyMetaClass getInstance(java.lang.Class theClass)

      convenience factory method for the most usual case.

    - #### initialize

          public void initialize()

      Description copied from class: `MetaClassImpl`
      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 java.lang.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 java.lang.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 java.lang.Object invokeMethod(java.lang.Object object,
                                               java.lang.String methodName,
                                               java.lang.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 object which the method was invoked on
        `methodName` - The name of the method
        `arguments` - The arguments to the method
      Returns:
        The return value of the method
      See Also:
        `MetaClass.invokeMethod(Class, Object, String, Object[], boolean, boolean)`

    - #### invokeStaticMethod

          public java.lang.Object invokeStaticMethod(java.lang.Object object,
                                                     java.lang.String methodName,
                                                     java.lang.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 java.lang.Object invokeConstructor(java.lang.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 java.lang.Object getProperty(java.lang.Class aClass,
                                              java.lang.Object object,
                                              java.lang.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(java.lang.Class aClass,
                                  java.lang.Object object,
                                  java.lang.String property,
                                  java.lang.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` - Whether the call was invoked from the inside or the outside of the class.

    - #### 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