org.metasyntactic.io
Class ClassDescriptor

java.lang.Object
  |
  +--org.metasyntactic.io.ClassDescriptor

public class ClassDescriptor

extends java.lang.Object

XMLSerializer's descriptor for classes. It contains the name and serialVersionUID of the class. The ClassDescriptor for a specific class loaded in this Java VM can be found/created using the lookup method.

Comments for fields and methods will often refer to 'clazz'. 'clazz' is the class that the current ClassDescriptor is a descriptor for.

Field Summary

protected static java.util.Map	classToDescriptor Cache of classes to their descriptors.
protected java.lang.Class	clazz Class that this is a descriptor for
protected java.lang.reflect.Field[]	fields Cached non-static and non-transient fields of clazz.
protected boolean	includeEverything
protected java.lang.reflect.Method	readResolveMethod Cached pointer to clazz's readResolve method (if clazz has such a method).
protected boolean	serializable True if and only if clazz is serializable, or inherits from a serializable class
protected long	suid Cached serial version UID for clazz
protected ClassDescriptor	superclassDescriptor Class descriptor for clazz's superclass
protected java.lang.reflect.Method	writeReplaceMethod Cached pointer to clazz's writeReplace method (if clazz has such a method).

Constructor Summary

protected

ClassDescriptor(java.lang.Class clazz, ClassDescriptor superclassDescriptor, boolean serializable, boolean includeEverything) Creates a new Class Descriptor with all (non-cached) fields filled in.

Method Summary

java.lang.Class	forClass() Returns the class that this is a descriptor for
java.lang.String	getClassName() Returns clazz's class name
java.lang.reflect.Field[]	getFields() Returns all the non-static non-transient fields of clazz.
long	getSerialVersionUID() Returns clazz's serial version UID
ClassDescriptor	getSuperclassDescriptor() Returns the class descriptor for clazz's superclass.
protected void	init() Initializes thi class descriptor.
static ClassDescriptor	lookup(java.lang.Class cl) Returns a ClassDescriptor for cl if cl is serializable, otherwise null.
static ClassDescriptor	lookup(java.lang.Class cl, boolean includeEverything)
protected static ClassDescriptor	lookupInternal(java.lang.Class cl, boolean includeEverything) Finds the actual class descriptor for cl.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

classToDescriptor

protected static java.util.Map classToDescriptor

Cache of classes to their descriptors. This map is not synchronized so all accessing methods must synchronize on it.

clazz

protected java.lang.Class clazz

Class that this is a descriptor for

fields

protected java.lang.reflect.Field[] fields

Cached non-static and non-transient fields of clazz.

superclassDescriptor

protected ClassDescriptor superclassDescriptor

Class descriptor for clazz's superclass

serializable

protected boolean serializable

True if and only if clazz is serializable, or inherits from a serializable class

suid

protected long suid

Cached serial version UID for clazz

See Also:

org.metasyntactic.util.StreamUniqueIdentifier#compute(java.lang.Class)

writeReplaceMethod

protected java.lang.reflect.Method writeReplaceMethod

Cached pointer to clazz's writeReplace method (if clazz has such a method). Otherwise, this is null.

readResolveMethod

protected java.lang.reflect.Method readResolveMethod

Cached pointer to clazz's readResolve method (if clazz has such a method). Otherwise, this is null.

includeEverything

protected boolean includeEverything

Constructor Detail

ClassDescriptor

protected ClassDescriptor(java.lang.Class clazz,
                          ClassDescriptor superclassDescriptor,
                          boolean serializable,
                          boolean includeEverything)

Creates a new Class Descriptor with all (non-cached) fields filled in. This should only be called from within lookup or lookupInternal

Parameters:

clazz - The class this is a descriptor for

superclassDescriptor - The descriptor for clazz's superclass

serializable - Whether or not clazz is serialiable

See Also:

lookup(java.lang.Class), #lookupInternal(java.lang.Class)

Method Detail

getClassName

public java.lang.String getClassName()

Returns clazz's class name

Returns:

clazz's class name

getSerialVersionUID

public long getSerialVersionUID()

Returns clazz's serial version UID

Returns:

clazz's serial version UID

getSuperclassDescriptor

public ClassDescriptor getSuperclassDescriptor()

Returns the class descriptor for clazz's superclass.

Returns:

The class descriptor for clazz's superclass

forClass

public java.lang.Class forClass()

Returns the class that this is a descriptor for

Returns:

The class that this is a descriptor for

getFields

public java.lang.reflect.Field[] getFields()

Returns all the non-static non-transient fields of clazz. This may be computationally intensive the first time it is called. But the results are cached, and all subsequent calls return the cached result

Returns:

The non-static non-transient fields of clazz.

lookup

public static ClassDescriptor lookup(java.lang.Class cl)

Returns a ClassDescriptor for cl if cl is serializable, otherwise null. Note! Just how there is only one instance of a class ever in memory, there is only ever one instance of each ClassDescriptor in memory

Parameters:

cl - The class to get a descriptor for.

Returns:

The ClassDescriptor for cl.

lookup

public static ClassDescriptor lookup(java.lang.Class cl,
                                     boolean includeEverything)

lookupInternal

protected static ClassDescriptor lookupInternal(java.lang.Class cl,
                                                boolean includeEverything)

Finds the actual class descriptor for cl. If one does not exist, it is created and then initialized

Parameters:

cl - The class to get the ClassDescriptor for

Returns:

The ClassDescriptor for cl.

init

protected void init()

Initializes thi class descriptor. This method fills in values such as 'fields', 'suid', 'writeReplaceMethod', and 'readResolveMethod'.

See Also:

fields, suid, writeReplaceMethod, readResolveMethod