ObjectStreamClass.java [plain text]
package java.io;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Member;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.security.DigestOutputStream;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.security.Security;
import java.util.Arrays;
import java.util.Comparator;
import java.util.Hashtable;
import java.util.Vector;
import gnu.java.io.NullOutputStream;
import gnu.java.lang.reflect.TypeSignature;
import gnu.java.security.provider.Gnu;
public class ObjectStreamClass implements Serializable
{
public static ObjectStreamClass lookup (Class cl)
{
if (cl == null)
return null;
if (! (Serializable.class).isAssignableFrom (cl))
return null;
ObjectStreamClass osc = (ObjectStreamClass)classLookupTable.get (cl);
if (osc != null)
return osc;
else
{
osc = new ObjectStreamClass (cl);
classLookupTable.put (cl, osc);
return osc;
}
}
public String getName ()
{
return name;
}
public Class forClass ()
{
return clazz;
}
public long getSerialVersionUID ()
{
return uid;
}
public ObjectStreamField[] getFields ()
{
ObjectStreamField[] copy = new ObjectStreamField[ fields.length ];
System.arraycopy (fields, 0, copy, 0, fields.length);
return copy;
}
public ObjectStreamField getField (String name)
{
for (int i=0; i < fields.length; i++)
if (fields[i].getName ().equals (name))
return fields[i];
return null;
}
public String toString ()
{
return "java.io.ObjectStreamClass< " + name + ", " + uid + " >";
}
boolean hasWriteMethod ()
{
return (flags & ObjectStreamConstants.SC_WRITE_METHOD) != 0;
}
boolean isSerializable ()
{
return (flags & ObjectStreamConstants.SC_SERIALIZABLE) != 0;
}
boolean isExternalizable ()
{
return (flags & ObjectStreamConstants.SC_EXTERNALIZABLE) != 0;
}
ObjectStreamClass getSuper ()
{
return superClass;
}
static ObjectStreamClass[] getObjectStreamClasses (Class clazz)
{
ObjectStreamClass osc = ObjectStreamClass.lookup (clazz);
ObjectStreamClass[] ret_val;
if (osc == null)
return new ObjectStreamClass[0];
else
{
Vector oscs = new Vector ();
while (osc != null)
{
oscs.addElement (osc);
osc = osc.getSuper ();
}
int count = oscs.size ();
ObjectStreamClass[] sorted_oscs = new ObjectStreamClass[ count ];
for (int i = count - 1; i >= 0; i--)
sorted_oscs[ count - i - 1 ] = (ObjectStreamClass)oscs.elementAt (i);
return sorted_oscs;
}
}
int getFlags ()
{
return flags;
}
ObjectStreamClass (String name, long uid, byte flags,
ObjectStreamField[] fields)
{
this.name = name;
this.uid = uid;
this.flags = flags;
this.fields = fields;
}
void setClass (Class cl) throws InvalidClassException
{
this.clazz = cl;
long class_uid = getClassUID (cl);
if (uid == 0)
{
uid = class_uid;
return;
}
if (uid != class_uid)
{
String msg = cl +
": Local class not compatible: stream serialVersionUID="
+ uid + ", local serialVersionUID=" + class_uid;
throw new InvalidClassException (msg);
}
}
void setSuperclass (ObjectStreamClass osc)
{
superClass = osc;
}
void calculateOffsets ()
{
int i;
ObjectStreamField field;
primFieldSize = 0;
int fcount = fields.length;
for (i = 0; i < fcount; ++ i)
{
field = fields[i];
if (! field.isPrimitive ())
break;
field.setOffset (primFieldSize);
switch (field.getTypeCode ())
{
case 'B':
case 'Z':
++ primFieldSize;
break;
case 'C':
case 'S':
primFieldSize += 2;
break;
case 'I':
case 'F':
primFieldSize += 4;
break;
case 'D':
case 'J':
primFieldSize += 8;
break;
}
}
for (objectFieldCount = 0; i < fcount; ++ i)
fields[i].setOffset (objectFieldCount++);
}
private ObjectStreamClass (Class cl)
{
uid = 0;
flags = 0;
clazz = cl;
name = cl.getName ();
setFlags (cl);
setFields (cl);
uid = getClassUID (cl);
superClass = lookup (cl.getSuperclass ());
}
private void setFlags (Class cl)
{
if ((java.io.Externalizable.class).isAssignableFrom (cl))
flags |= ObjectStreamConstants.SC_EXTERNALIZABLE;
else if ((java.io.Serializable.class).isAssignableFrom (cl))
flags |= ObjectStreamConstants.SC_SERIALIZABLE;
try
{
Method writeMethod = cl.getDeclaredMethod ("writeObject",
writeMethodArgTypes);
int modifiers = writeMethod.getModifiers ();
if (writeMethod.getReturnType () == Void.TYPE
&& Modifier.isPrivate (modifiers)
&& !Modifier.isStatic (modifiers))
flags |= ObjectStreamConstants.SC_WRITE_METHOD;
}
catch (NoSuchMethodException oh_well)
{}
}
private void setFields (Class cl)
{
if (! isSerializable () || isExternalizable ())
{
fields = NO_FIELDS;
return;
}
try
{
Field serialPersistentFields
= cl.getDeclaredField ("serialPersistentFields");
int modifiers = serialPersistentFields.getModifiers ();
if (Modifier.isStatic (modifiers)
&& Modifier.isFinal (modifiers)
&& Modifier.isPrivate (modifiers))
{
fields = getSerialPersistentFields (cl);
Arrays.sort (fields);
calculateOffsets ();
return;
}
}
catch (NoSuchFieldException ignore)
{}
int num_good_fields = 0;
Field[] all_fields = cl.getDeclaredFields ();
int modifiers;
for (int i=0; i < all_fields.length; i++)
{
modifiers = all_fields[i].getModifiers ();
if (Modifier.isTransient (modifiers)
|| Modifier.isStatic (modifiers))
all_fields[i] = null;
else
num_good_fields++;
}
fields = new ObjectStreamField[ num_good_fields ];
for (int from=0, to=0; from < all_fields.length; from++)
if (all_fields[from] != null)
{
Field f = all_fields[from];
fields[to] = new ObjectStreamField (f.getName (), f.getType ());
to++;
}
Arrays.sort (fields);
calculateOffsets ();
}
private long getClassUID (Class cl)
{
try
{
Field suid = cl.getDeclaredField ("serialVersionUID");
int modifiers = suid.getModifiers ();
if (Modifier.isStatic (modifiers) && Modifier.isFinal (modifiers))
return suid.getLong (null);
}
catch (NoSuchFieldException ignore)
{
}
catch (IllegalAccessException ignore)
{
}
try
{
MessageDigest md = null;
DigestOutputStream digest_out = null;
DataOutputStream data_out = null;
try
{
md = MessageDigest.getInstance ("SHA");
}
catch (NoSuchAlgorithmException e)
{
Gnu gnuProvider = new Gnu();
Security.addProvider(gnuProvider);
md = MessageDigest.getInstance ("SHA");
}
digest_out = new DigestOutputStream (nullOutputStream, md);
data_out = new DataOutputStream (digest_out);
data_out.writeUTF (cl.getName ());
int modifiers = cl.getModifiers ();
modifiers = modifiers & (Modifier.ABSTRACT | Modifier.FINAL
| Modifier.INTERFACE | Modifier.PUBLIC);
data_out.writeInt (modifiers);
if (! cl.isArray ())
{
Class[] interfaces = cl.getInterfaces ();
Arrays.sort (interfaces, interfaceComparator);
for (int i=0; i < interfaces.length; i++)
data_out.writeUTF (interfaces[i].getName ());
}
Field field;
Field[] fields = cl.getDeclaredFields ();
Arrays.sort (fields, memberComparator);
for (int i=0; i < fields.length; i++)
{
field = fields[i];
modifiers = field.getModifiers ();
if (Modifier.isPrivate (modifiers)
&& (Modifier.isStatic (modifiers)
|| Modifier.isTransient (modifiers)))
continue;
data_out.writeUTF (field.getName ());
data_out.writeInt (modifiers);
data_out.writeUTF (TypeSignature.getEncodingOfClass (field.getType ()));
}
boolean has_init;
try
{
has_init = hasClassInitializer (cl);
}
catch (NoSuchMethodError e)
{
has_init = false;
}
if (has_init)
{
data_out.writeUTF ("<clinit>");
data_out.writeInt (Modifier.STATIC);
data_out.writeUTF ("()V");
}
Constructor constructor;
Constructor[] constructors = cl.getDeclaredConstructors ();
Arrays.sort (constructors, memberComparator);
for (int i=0; i < constructors.length; i++)
{
constructor = constructors[i];
modifiers = constructor.getModifiers ();
if (Modifier.isPrivate (modifiers))
continue;
data_out.writeUTF ("<init>");
data_out.writeInt (modifiers);
data_out.writeUTF (
TypeSignature.getEncodingOfConstructor (constructor).replace ('/','.'));
}
Method method;
Method[] methods = cl.getDeclaredMethods ();
Arrays.sort (methods, memberComparator);
for (int i=0; i < methods.length; i++)
{
method = methods[i];
modifiers = method.getModifiers ();
if (Modifier.isPrivate (modifiers))
continue;
data_out.writeUTF (method.getName ());
data_out.writeInt (modifiers);
data_out.writeUTF (
TypeSignature.getEncodingOfMethod (method).replace ('/', '.'));
}
data_out.close ();
byte[] sha = md.digest ();
long result = 0;
int len = sha.length < 8 ? sha.length : 8;
for (int i=0; i < len; i++)
result += (long)(sha[i] & 0xFF) << (8 * i);
return result;
}
catch (NoSuchAlgorithmException e)
{
throw new RuntimeException ("The SHA algorithm was not found to use in computing the Serial Version UID for class "
+ cl.getName ());
}
catch (IOException ioe)
{
throw new RuntimeException (ioe.getMessage ());
}
}
private ObjectStreamField[] getSerialPersistentFields (Class clazz)
{
ObjectStreamField[] o = null;
try
{
Field f = clazz.getDeclaredField ("getSerialPersistentFields");
o = (ObjectStreamField[])f.get (null);
}
catch (java.lang.NoSuchFieldException e)
{
}
catch (java.lang.IllegalAccessException e)
{
}
return o;
}
private static boolean hasClassInitializer (Class clazz)
throws java.lang.NoSuchMethodError
{
Method m = null;
try
{
Class classArgs[] = {};
m = clazz.getDeclaredMethod ("<clinit>", classArgs);
}
catch (java.lang.NoSuchMethodException e)
{
throw new java.lang.NoSuchMethodError ();
}
return m != null;
}
public static final ObjectStreamField[] NO_FIELDS = {};
private static Hashtable classLookupTable = new Hashtable ();
private static final NullOutputStream nullOutputStream = new NullOutputStream ();
private static final Comparator interfaceComparator = new InterfaceComparator ();
private static final Comparator memberComparator = new MemberComparator ();
private static final
Class[] writeMethodArgTypes = { java.io.ObjectOutputStream.class };
private ObjectStreamClass superClass;
private Class clazz;
private String name;
private long uid;
private byte flags;
ObjectStreamField[] fields;
int primFieldSize = -1; int objectFieldCount;
private static final long serialVersionUID = -6120832682080437368L;
}
class InterfaceComparator implements Comparator
{
public int compare (Object o1, Object o2)
{
return ((Class)o1).getName ().compareTo (((Class)o2).getName ());
}
}
class MemberComparator implements Comparator
{
public int compare (Object o1, Object o2)
{
Member m1 = (Member)o1;
Member m2 = (Member)o2;
int comp = m1.getName ().compareTo (m2.getName ());
if (comp == 0)
return TypeSignature.getEncodingOfMember (m1).
compareTo (TypeSignature.getEncodingOfMember (m2));
else
return comp;
}
}