CONTENTS | PREV | NEXT Java Object Serialization Specification


6.4.1 Rules of the Grammar

A Serialized stream is represented by any stream satisfying the stream rule.

stream:
  magic version contents
contents:
  content
  contents content
content:
  object
  blockdata
object:
  newObject
  newClass
  newArray
  newString
  newClassDesc
  prevObject
  nullReference
  exception
  TC_RESET
newClass:
  TC_CLASS classDesc newHandle
classDesc:
  newClassDesc
  nullReference
  (ClassDesc)prevObject      // an object required to be of type
                               // ClassDesc
superClassDesc:
  classDesc
newClassDesc:
  TC_CLASSDESC className serialVersionUID newHandle classDescInfo
  TC_PROXYCLASSDESC newHandle proxyClassDescInfo
classDescInfo:
  classDescFlags fields classAnnotation superClassDesc 
className:
  (utf)
serialVersionUID:
  (long)
classDescFlags:
  (byte)                  // Defined in Terminal Symbols and
                            // Constants
proxyClassDescInfo:
  (int)<count> proxyInterfaceName[count] classAnnotation
      superClassDesc
proxyInterfaceName:
  (utf)
fields:
  (short)<count>  fieldDesc[count]
fieldDesc:
  primitiveDesc
  objectDesc
primitiveDesc:
  prim_typecode fieldName
objectDesc:
  obj_typecode fieldName className1
fieldName:
  (utf)
className1:
  (String)object             // String containing the field's type
classAnnotation:
  endBlockData
  contents endBlockData      // contents written by annotateClass
prim_typecode:
  `B'	// byte
  `C'	// char
  `D'	// double
  `F'	// float
  `I'	// integer
  `J'	// long
  `S'	// short
  `Z'	// boolean
obj_typecode:
  `[`	// array
  `L'	// object
newArray:
  TC_ARRAY classDesc newHandle (int)<size> values[size]
newObject:
  TC_OBJECT classDesc newHandle classdata[]  // data for each class
classdata:
  nowrclass                 // SC_SERIALIZABLE & classDescFlag &&
                            // !(SC_WRITE_METHOD & classDescFlags)
  wrclass objectAnnotation  // SC_SERIALIZABLE & classDescFlag &&
                            // SC_WRITE_METHOD & classDescFlags
  externalContents          // SC_EXTERNALIZABLE & classDescFlag &&
                            // !(SC_BLOCKDATA  & classDescFlags
  objectAnnotation          // SC_EXTERNALIZABLE & classDescFlag&& 
                            // SC_BLOCKDATA & classDescFlags
nowrclass:
  values                    // fields in order of class descriptor
wrclass:
  nowrclass
objectAnnotation:
  endBlockData
  contents endBlockData     // contents written by writeObject
                            // or writeExternal PROTOCOL_VERSION_2.
blockdata:
  blockdatashort
  blockdatalong
blockdatashort:
  TC_BLOCKDATA (unsigned byte)<size> (byte)[size]
blockdatalong:
  TC_BLOCKDATALONG (int)<size> (byte)[size]
endBlockData	:
  TC_ENDBLOCKDATA
externalContent:          // Only parseable by readExternal
  ( bytes)                // primitive data
    object
externalContents:         // externalContent written by 
  externalContent         // writeExternal in PROTOCOL_VERSION_1.
  externalContents externalContent
newString:
  TC_STRING newHandle (utf)
  TC_LONGSTRING newHandle (long-utf)
prevObject
  TC_REFERENCE (int)handle
nullReference
  TC_NULL
exception:
  TC_EXCEPTION reset (Throwable)object	 reset 
magic:
  STREAM_MAGIC
version
  STREAM_VERSION
values:          // The size and types are described by the
                 // classDesc for the current object
newHandle:       // The next number in sequence is assigned
                 // to the object being serialized or deserialized
reset:           // The set of known objects is discarded
                 // so the objects of the exception do not
                 // overlap with the previously sent objects 
                 // or with objects that may be sent after 
                 // the exception


CONTENTS | PREV | NEXT
Copyright © 1997-1999 Sun Microsystems, Inc. All Rights Reserved.