Class ClassMetaobject

  • All Implemented Interfaces:
    Serializable

    public class ClassMetaobject
    extends Object
    implements Serializable
    A runtime class metaobject.

    A ClassMetaobject is created for every class of reflective objects. It can be used to hold values shared among the reflective objects of the same class.

    To obtain a class metaobject, calls _getClass() on a reflective object. For example,

    ClassMetaobject cm = ((Metalevel)reflectiveObject)._getClass();
     
    See Also:
    Metaobject, Metalevel, Serialized Form
    • Field Detail

      • useContextClassLoader

        public static boolean useContextClassLoader
        Specifies how a java.lang.Class object is loaded.

        If true, it is loaded by:

        Thread.currentThread().getContextClassLoader().loadClass()

        If false, it is loaded by Class.forName(). The default value is false.

    • Constructor Detail

      • ClassMetaobject

        public ClassMetaobject​(String[] params)
        Constructs a ClassMetaobject.
        Parameters:
        params - params[0] is the name of the class of the reflective objects.
    • Method Detail

      • getJavaClass

        public final Class<?> getJavaClass()
        Obtains the java.lang.Class representing this class.
      • getName

        public final String getName()
        Obtains the name of this class.
      • isInstance

        public final boolean isInstance​(Object obj)
        Returns true if obj is an instance of this class.
      • trapFieldRead

        public Object trapFieldRead​(String name)
        Is invoked when static fields of the base-level class are read and the runtime system intercepts it. This method simply returns the value of the field.

        Every subclass of this class should redefine this method.

      • trapFieldWrite

        public void trapFieldWrite​(String name,
                                   Object value)
        Is invoked when static fields of the base-level class are modified and the runtime system intercepts it. This method simply sets the field to the given value.

        Every subclass of this class should redefine this method.

      • trapMethodcall

        public Object trapMethodcall​(int identifier,
                                     Object[] args)
                              throws Throwable
        Is invoked when static methods of the base-level class are called and the runtime system intercepts it. This method simply executes the intercepted method invocation with the original parameters and returns the resulting value.

        Every subclass of this class should redefine this method.

        Throws:
        Throwable
      • getReflectiveMethods

        public final Method[] getReflectiveMethods()
        Returns an array of the methods defined on the given reflective object. This method is for the internal use only.
      • getMethod

        public final Method getMethod​(int identifier)
        Returns the java.lang.reflect.Method object representing the method specified by identifier.

        Note that the actual method returned will be have an altered, reflective name i.e. _m_2_...

        Parameters:
        identifier - the identifier index given to trapMethodcall() etc.
        See Also:
        Metaobject.trapMethodcall(int,Object[]), trapMethodcall(int,Object[])
      • getMethodName

        public final String getMethodName​(int identifier)
        Returns the name of the method specified by identifier.
      • getParameterTypes

        public final Class<?>[] getParameterTypes​(int identifier)
        Returns an array of Class objects representing the formal parameter types of the method specified by identifier.
      • getReturnType

        public final Class<?> getReturnType​(int identifier)
        Returns a Class objects representing the return type of the method specified by identifier.
      • getMethodIndex

        public final int getMethodIndex​(String originalName,
                                        Class<?>[] argTypes)
                                 throws NoSuchMethodException
        Returns the identifier index of the method, as identified by its original name.

        This method is useful, in conjuction with getMethod(int), to obtain a quick reference to the original method in the reflected class (i.e. not the proxy method), using the original name of the method.

        Written by Brett Randall and Shigeru Chiba.

        Parameters:
        originalName - The original name of the reflected method
        argTypes - array of Class specifying the method signature
        Returns:
        the identifier index of the original method
        Throws:
        NoSuchMethodException - if the method does not exist
        See Also:
        getMethod(int)