objectstreamclass_1_3_1.java

JAVA的一些源码 JAVA2 STANDARD EDITION DEVELOPMENT KIT 5.0

		     * size once the number of fields is known.
		     */
                    Field[] actualfields = cl.getDeclaredFields();

		    int numFields = 0;
		    ObjectStreamField[] tempFields =
			new ObjectStreamField[actualfields.length];
		    for (int i = 0; i < actualfields.length; i++) {
			int modifiers = actualfields[i].getModifiers();
			if (!Modifier.isStatic(modifiers) &&
			    !Modifier.isTransient(modifiers)) {
			    tempFields[numFields++] =
				new ObjectStreamField(actualfields[i]);
			}
		    }
		    fields = new ObjectStreamField[numFields];
		    System.arraycopy(tempFields, 0, fields, 0, numFields);

		} else {
		    // For each declared persistent field, look for an actual
		    // reflected Field. If there is one, make sure it's the correct
		    // type and cache it in the ObjectStreamClass_1_3_1 for that field.
		    for (int j = fields.length-1; j >= 0; j--) {
			try {
                            Field reflField = cl.getDeclaredField(fields[j].getName());
			    if (fields[j].getType() == reflField.getType()) {
				// reflField.setAccessible(true);
				fields[j].setField(reflField);
			    }
			} catch (NoSuchFieldException e) {
			    // Nothing to do
			}
		    }
		}
	        return null;
	    }
	    });

	    if (fields.length > 1)
		Arrays.sort(fields);

	    /* Set up field data for use while writing using the API api. */
	    computeFieldInfo();
	}

        /* Get the serialVersionUID from the class.
         * It uses the access override mechanism so make sure
         * the field objects is only used here.
         *
         * NonSerializable classes have a serialVerisonUID of 0L.
         */
         if (isNonSerializable()) {
             suid = 0L;
         } else {
             // Lookup special Serializable members using reflection.
             AccessController.doPrivileged(new PrivilegedAction() {
                public Object run() {
                if (forProxyClass) {
                    // proxy classes always have serialVersionUID of 0L
                    suid = 0L;
                } else {
	            try {
                        final Field f = cl.getDeclaredField("serialVersionUID");
	                int mods = f.getModifiers();
		    // SerialBug 5:  static final SUID should be read
	                if (Modifier.isStatic(mods) && 
                            Modifier.isFinal(mods) ) {
                            f.setAccessible(true);
		            suid = f.getLong(cl);
	                    // get rid of native code
	                    // suid = getSerialVersionUIDField(cl);
	            // SerialBug 2: should be computed after writeObject
	            // actualSuid = computeStructuralUID(cl);
	                } else {
		            suid = ObjectStreamClass.getSerialVersionUID(cl);
	                    // SerialBug 2: should be computed after writeObject
	                    // actualSuid = computeStructuralUID(cl);
	                }
	            } catch (NoSuchFieldException ex) {
	                suid = ObjectStreamClass.getSerialVersionUID(cl);
	                // SerialBug 2: should be computed after writeObject
	                // actualSuid = computeStructuralUID(cl);
                    } catch (IllegalAccessException ex) {
                        suid = ObjectStreamClass.getSerialVersionUID(cl);
                    }
	        }


	        try {
                    writeReplaceObjectMethod = cl.getDeclaredMethod("writeReplace", noTypesList);
	            if (Modifier.isStatic(writeReplaceObjectMethod.getModifiers())) {
	                writeReplaceObjectMethod = null;
                    } else {
                        writeReplaceObjectMethod.setAccessible(true);
                    } 

	        } catch (NoSuchMethodException e2) {

	        }
	
	        try {
                    readResolveObjectMethod = cl.getDeclaredMethod("readResolve", noTypesList);
	            if (Modifier.isStatic(readResolveObjectMethod.getModifiers())) {
	               readResolveObjectMethod = null;
                    } else {
                       readResolveObjectMethod.setAccessible(true);
                    }

	        } catch (NoSuchMethodException e2) {

	        }
	
                /* Cache lookup of writeObject and readObject for
                 * Serializable classes. (Do not lookup for
                 * Externalizable)
                 */

                if (serializable && !forProxyClass) {

	            /* Look for the writeObject method
	             * Set the accessible flag on it here. ObjectOutputStream
	             * will call it as necessary.
	             */
	            try {
	              Class[] args = {java.io.ObjectOutputStream.class};
                      writeObjectMethod = cl.getDeclaredMethod("writeObject", args);
	              hasWriteObjectMethod = true;
	              int mods = writeObjectMethod.getModifiers();

	              // Method must be private and non-static
	              if (!Modifier.isPrivate(mods) ||
		        Modifier.isStatic(mods)) {
		        writeObjectMethod = null;
		        hasWriteObjectMethod = false;
	              }

	            } catch (NoSuchMethodException e) {
	            }

	            /* Look for the readObject method
	             * set the access override and save the reference for
	             * ObjectInputStream so it can all the method directly.
	             */
	            try {
	              Class[] args = {java.io.ObjectInputStream.class};
                      readObjectMethod = cl.getDeclaredMethod("readObject", args);
	              int mods = readObjectMethod.getModifiers();

	              // Method must be private and non-static
	              if (!Modifier.isPrivate(mods) ||
		        Modifier.isStatic(mods)) {
		        readObjectMethod = null;
	              }
	            } catch (NoSuchMethodException e) {
                    }
                    // Compute the structural UID.  This must be done after the
                    // calculation for writeObject.  Fixed 4/20/2000, eea1
	            // SerialBug 2: to have correct value in RepId
	        }
	        return null;
	    }
	  });
	}

        actualSuid = computeStructuralUID(this, cl);
      }

    }

    /*
     * Create an empty ObjectStreamClass_1_3_1 for a class about to be read.
     * This is separate from read so ObjectInputStream can assign the
     * wire handle early, before any nested ObjectStreamClass_1_3_1 might
     * be read.
     */
    ObjectStreamClass_1_3_1(String n, long s) {
	name = n;
	suid = s;
	superclass = null;
    }

    private static Object[] translateFields(Object objs[])
        throws NoSuchFieldException {
        try{
            java.io.ObjectStreamField fields[] = (java.io.ObjectStreamField[])objs;
            Object translation[] = null;
                       
            if (translatedFields == null)
                translatedFields = new Hashtable();
                       
            translation = (Object[])translatedFields.get(fields);
                       
            if (translation != null)
                return translation;
            else {
                Class osfClass = com.sun.corba.se.impl.orbutil.ObjectStreamField.class;

                translation = (Object[])java.lang.reflect.Array.newInstance(osfClass, objs.length);
                Object arg[] = new Object[2];
                Class types[] = {String.class, Class.class};
                Constructor constructor = osfClass.getDeclaredConstructor(types);
                for (int i = fields.length -1; i >= 0; i--){
                    arg[0] = fields[i].getName();
                    arg[1] = fields[i].getType();
                       
                    translation[i] = constructor.newInstance(arg);
                }
                translatedFields.put(fields, translation);
                       
            }

            return (Object[])translation;
        }
        catch(Throwable t){
            throw new NoSuchFieldException();
        }
    }

    /* Compare the base class names of streamName and localName.
     *
     * @return  Return true iff the base class name compare.
     * @parameter streamName	Fully qualified class name.
     * @parameter localName	Fully qualified class name.
     * @parameter pkgSeparator	class names use either '.' or '/'.
     *
     * Only compare base class name to allow package renaming.
     */
    static boolean compareClassNames(String streamName,
				     String localName,
				     char pkgSeparator) {
	/* compare the class names, stripping off package names. */
	int streamNameIndex = streamName.lastIndexOf(pkgSeparator);
	if (streamNameIndex < 0)
	    streamNameIndex = 0;

	int localNameIndex = localName.lastIndexOf(pkgSeparator);
	if (localNameIndex < 0)
	    localNameIndex = 0;

	return streamName.regionMatches(false, streamNameIndex,
					localName, localNameIndex,
					streamName.length() - streamNameIndex);
    }

    /*
     * Compare the types of two class descriptors.
     * They match if they have the same class name and suid
     */
    final boolean typeEquals(ObjectStreamClass_1_3_1 other) {
	return (suid == other.suid) &&
	    compareClassNames(name, other.name, '.');
    }

    /*
     * Return the superclass descriptor of this descriptor.
     */
    final void setSuperclass(ObjectStreamClass_1_3_1 s) {
	superclass = s;
    }

    /*
     * Return the superclass descriptor of this descriptor.
     */
    final ObjectStreamClass_1_3_1 getSuperclass() {
	return superclass;
    }

    /*
     * Return whether the class has a writeObject method
     */
    final boolean hasWriteObject() {
	return hasWriteObjectMethod;
    }

    final boolean isCustomMarshaled() {
	return (hasWriteObject() || isExternalizable());
    }

    /*
     * Return true if all instances of 'this' Externalizable class
     * are written in block-data mode from the stream that 'this' was read
     * from. <p>
     *
     * In JDK 1.1, all Externalizable instances are not written
     * in block-data mode.
     * In JDK 1.2, all Externalizable instances, by default, are written
     * in block-data mode and the Externalizable instance is terminated with
     * tag TC_ENDBLOCKDATA. Change enabled the ability to skip Externalizable
     * instances.
     *
     * IMPLEMENTATION NOTE:
     *   This should have been a mode maintained per stream; however,
     *   for compatibility reasons, it was only possible to record
     *   this change per class. All Externalizable classes within
     *   a given stream should either have this mode enabled or
     *   disabled. This is enforced by not allowing the PROTOCOL_VERSION
     *   of a stream to he changed after any objects have been written.
     *
     * @see ObjectOutputStream#useProtocolVersion
     * @see ObjectStreamConstants#PROTOCOL_VERSION_1
     * @see ObjectStreamConstants#PROTOCOL_VERSION_2
     *
     * @since JDK 1.2
     */
    boolean hasExternalizableBlockDataMode() {
	return hasExternalizableBlockData;
    }

    /*
     * Return the ObjectStreamClass_1_3_1 of the local class this one is based on.
     */
    final ObjectStreamClass_1_3_1 localClassDescriptor() {
	return localClassDesc;
    }

    /*
     * Get the Serializability of the class.
     */
    boolean isSerializable() {
	return serializable;
    }

    /*
     * Get the externalizability of the class.
     */
    boolean isExternalizable() {
	return externalizable;
    }

    boolean isNonSerializable() {
        return ! (externalizable || serializable);
    }

    /*
     * Calculate the size of the array needed to store primitive data and the
     * number of object references to read when reading from the input
     * stream.
     */
    private void computeFieldInfo() {
	primBytes = 0;
	objFields = 0;

	for (int i = 0; i < fields.length; i++ ) {
	    switch (fields[i].getTypeCode()) {
	    case 'B':
	    case 'Z':
	    	primBytes += 1;
	    	break;
	    case 'C':
	    case 'S':
	    	primBytes += 2;
	    	break;

	    case 'I':
	    case 'F':
	    	primBytes += 4;
	    	break;
	    case 'J':
	    case 'D' :
	    	primBytes += 8;
	    	break;

	    case 'L':
	    case '[':
	    	objFields += 1;
	    	break;
	    }
	}
    }

    private static long computeStructuralUID(ObjectStreamClass_1_3_1 osc, Class cl) {
	ByteArrayOutputStream devnull = new ByteArrayOutputStream(512);
		
	long h = 0;
	try {

	    if ((!java.io.Serializable.class.isAssignableFrom(cl)) ||
		(cl.isInterface())){
		return 0;
	    }
			
	    if (java.io.Externalizable.class.isAssignableFrom(cl)) {
		return 1;
	    }

	    MessageDigest md = MessageDigest.getInstance("SHA");
	    DigestOutputStream mdo = new DigestOutputStream(devnull, md);
	    DataOutputStream data = new DataOutputStream(mdo);

	    // Get SUID of parent
	    Class parent = cl.getSuperclass();
	    if ((parent != null))  
	    // SerialBug 1; acc. to spec the one for 
	    // java.lang.object
	    // should be computed and put
	    //     && (parent != java.lang.Object.class)) 
	    {
				//data.writeLong(computeSerialVersionUID(null,parent));
		data.writeLong(computeStructuralUID(lookup(parent), parent));
	    }

	    if (osc.hasWriteObject())
		data.writeInt(2);
	    else
		data.writeInt(1);

	    /* Sort the field names to get a deterministic order */
            // Field[] field = ObjectStreamClass_1_3_1.getDeclaredFields(cl);

            ObjectStreamField[] fields = osc.getFields();

            // Must make sure that the Field array we allocate
            // below is exactly the right size.  Bug fix for
            // 4397133.
            int numNonNullFields = 0;
            for (int i = 0; i < fields.length; i++)
                if (fields[i].getField() != null)
                    numNonNullFields++;

            Field [] field = new java.lang.reflect.Field[numNonNullFields];
            for (int i = 0, fieldNum = 0; i < fields.length; i++) {