Package org.codehaus.groovy.reflection

Class ClassInfo

java.lang.Object
org.codehaus.groovy.reflection.ClassInfo
All Implemented Interfaces:
Finalizable
public class ClassInfo extends Object implements Finalizable
Handle for all information we want to keep about the class

This class handles caching internally and it's advisable to not store references directly to objects of this class. The static factory method getClassInfo(Class) should be used to retrieve an instance from the cache. Internally the Class associated with a ClassInfo instance is kept as WeakReference, so it not safe to reference and instance without the Class being either strongly or softly reachable.

  • Field Details

  • Method Details

    • getVersion

      public int getVersion()
      Returns the version number of this class information. The version increments when the metaclass is modified (e.g., methods/properties added).
      Returns:
      the current version

    • incVersion

      public void incVersion()
      Increments the version number and invalidates call sites. Called when metaclass modifications occur (e.g., adding methods to an ExpandoMetaClass).

    • getModifiedExpando

      public ExpandoMetaClass getModifiedExpando()
      Returns the modified ExpandoMetaClass for this class, if one exists.
      Returns:
      the modified expando metaclass, or null if not modified or not an ExpandoMetaClass

    • clearModifiedExpandos

      public static void clearModifiedExpandos()
      Clears all modified ExpandoMetaClass instances for all classes. Removes strong references to metaclasses and disassociates them from their class information.

    • getTheClass

      public final Class<?> getTheClass()
      Returns the Class associated with this ClassInfo.

      This method can return null if the Class is no longer reachable through any strong or soft references. A non-null return value indicates that this ClassInfo is valid.

      Returns:
      the Class associated with this ClassInfo, else null

    • getCachedClass

      public CachedClass getCachedClass()
      Returns the cached class representation for this class. Lazily initializes on first access.
      Returns:
      the cached class

    • getArtifactClassLoader

      public ClassLoaderForClassArtifacts getArtifactClassLoader()
      Returns the class loader for loading class artifacts (e.g., compiled bytecode). Lazily initializes on first access.
      Returns:
      the artifact class loader

    • getClassInfo

      public static ClassInfo getClassInfo(Class cls)
      Retrieves the ClassInfo for the given class. Lazily creates one if not already cached.
      Parameters:
      cls - the class to get information for
      Returns:
      the class information, or null if cls is null

    • remove

      public static void remove(Class<?> cls)
      Removes a ClassInfo from the cache. This is useful in cases where the Class is parsed from a script, such as when using GroovyClassLoader#parseClass, and is executed for its result but the Class is not retained or cached. Removing the ClassInfo associated with the Class will make the Class and its ClassLoader eligible for garbage collection sooner that it would otherwise.
      Parameters:
      cls - the Class associated with the ClassInfo to remove from cache

    • getAllClassInfo

      public static Collection<ClassInfo> getAllClassInfo()
      Returns all cached class information across the runtime.
      Returns:
      a collection of all cached class info objects

    • onAllClassInfo

      public static void onAllClassInfo(ClassInfo.ClassInfoAction action)
      Executes the given action on all cached class information. Allows processing of all classes currently tracked by the runtime.
      Parameters:
      action - the action to execute on each ClassInfo

    • getStrongMetaClass

      public MetaClass getStrongMetaClass()
      Returns the strong (immutable) metaclass for this class, if one has been set. A strong reference keeps the metaclass in memory regardless of garbage collection.
      Returns:
      the strong metaclass, or null if not set

    • setStrongMetaClass

      public void setStrongMetaClass(MetaClass answer)
      Sets the strong (immutable) metaclass for this class. Increments the version number and manages ExpandoMetaClass registry.
      Parameters:
      answer - the metaclass to set, or null to clear

    • getWeakMetaClass

      public MetaClass getWeakMetaClass()
      Returns the weak (mutable) metaclass for this class, if one has been set. A weak reference allows garbage collection of the metaclass when no longer needed.
      Returns:
      the weak metaclass, or null if not set or if it has been garbage collected

    • setWeakMetaClass

      public void setWeakMetaClass(MetaClass answer)
      Sets the weak (mutable) metaclass for this class. Clears the strong metaclass and increments the version number.
      Parameters:
      answer - the metaclass to set, or null to clear

    • getMetaClassForClass

      public MetaClass getMetaClassForClass()
      Returns the most appropriate metaclass for this class. Prefers strong metaclass if available, then weak metaclass if valid, otherwise the default.
      Returns:
      the metaclass for this class

    • getMetaClass

      public final MetaClass getMetaClass()
      Returns the MetaClass for the Class associated with this ClassInfo. If no MetaClass exists one will be created.

      It is not safe to call this method without a Class associated with this ClassInfo. It is advisable to always retrieve a ClassInfo instance from the cache by using the static factory method getClassInfo(Class) to ensure the referenced Class is strongly reachable.

      Returns:
      a MetaClass instance

    • getMetaClass

      public MetaClass getMetaClass(Object obj)
      Returns the metaclass for an object. If the object has a per-instance metaclass, returns that; otherwise returns this class's metaclass.
      Parameters:
      obj - the object to get the metaclass for
      Returns:
      the metaclass for the object

    • size

      public static int size()
      Returns the number of cached class information entries.
      Returns:
      the count of cached ClassInfo instances

    • fullSize

      public static int fullSize()
      Returns the total size including soft-referenced (potentially garbage-collectable) entries.
      Returns:
      the full count of class information entries

    • lock

      public void lock()
      Acquires a lock for this class information. Used to synchronize modifications to metaclass and per-instance metaclass maps.

    • unlock

      public void unlock()
      Releases the lock for this class information.

    • getPerInstanceMetaClass

      public MetaClass getPerInstanceMetaClass(Object obj)
      Returns the per-instance metaclass for the given object, if one has been set.
      Parameters:
      obj - the object to get the per-instance metaclass for
      Returns:
      the per-instance metaclass, or null if not set

    • setPerInstanceMetaClass

      public void setPerInstanceMetaClass(Object obj, MetaClass metaClass)
      Sets the per-instance metaclass for the given object. Per-instance metaclasses override the class-level metaclass for that specific object.
      Parameters:
      obj - the object to associate with a metaclass
      metaClass - the metaclass to set, or null to remove the association

    • hasPerInstanceMetaClasses

      public boolean hasPerInstanceMetaClasses()
      Returns whether this class has any per-instance metaclasses associated with its objects.
      Returns:
      true if one or more per-instance metaclasses have been set; false otherwise

    • finalizeReference

      public void finalizeReference()
      Description copied from interface: Finalizable
      Performs any cleanup required after the associated reference has been cleared.
      Specified by:
      finalizeReference in interface Finalizable