Java Object Serialization Specification: 6 - Object Serialization Stream Protocol - JDK 5 Documentation v1.2.2, Java 2 SDK 英文文档

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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
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

classDescInfo:

classDescFlags fields classAnnotation superClassDesc

className:

(utf)

serialVersionUID:

(long)

classDescFlags:

(byte) // Defined in Terminal Symbols and Constants

fields:

(short)<count> fieldDesc[count]

fieldDesc:

primitiveDesc
objectDesc

primitiveDesc:

prim_typecode fieldName

objectDesc:

obj_typecode fieldName className1

fieldName:

(utf)

className1:

(String)object // String contains field 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
// primitive data

(bytes)object

externalContents: // externalContent written by writeExternal
// in PROTOCOL_VERSION_1.

externalContent
externalContents externalContent

newString:

TC_STRING newHandle (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

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