Java Object Serialization - Revision history

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Effect2: Created page with "{{FormatInfo |formattype=electronic |subcat=Serialization |released=1997 }} '''Java Object Serialization''', often referred to by third-party sources as simply '''Java serial..."

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Created page with "{{FormatInfo |formattype=electronic |subcat=Serialization |released=1997 }} '''Java Object Serialization''', often referred to by third-party sources as simply '''Java serial..."

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'''Java Object Serialization''', often referred to by third-party sources as simply '''Java serialization''', is the native [[serialization]] format for the [[Java]] programming language, analogous to the [[Pickle]] format for [[Python]]. It appears to have been introduced in 1997<ref name="wvh">[[Wikipedia:Java version history]]</ref>, with version 1.1.<ref name="12vs">https://docs.oracle.com/en/java/javase/12/docs/specs/serialization/protocol.html#stream-protocol-versions</ref>

== Versions ==
There are three different things in or attributes of a Java Object Serialization stream that are referred to by "version":
* "protocol version", which corresponds to the usual meaning of "version";
* an integer field in the header called "STREAM_VERSION" or just "version", which has been 5<ref>https://www.cs.princeton.edu/courses/archive/fall97/cs461/jdkdocs/guide/serialization/spec/protocol.doc.html#9303</ref><ref>https://docs.oracle.com/en/java/javase/12/docs/specs/serialization/protocol.html#terminal-symbols-and-constants</ref> since at least JDK 1.1.4<ref>https://www.cs.princeton.edu/courses/archive/fall97/cs461/jdkdocs/</ref>, released between 1997 and 1998<ref name="wvh" />, meaning that it has had the value of 5 for almost all of the format's existence;
* and the "version" not of the Object Serialization format, but of whatever format is built on top of it<ref>https://docs.oracle.com/en/java/javase/12/docs/specs/serialization/version.html</ref>.
The "protocol version" can be either 1 or 2. The second version was made standard in the Java platform in version 1.2<ref name="12vs" /> in December 1998<ref name="wvh" />. Java versions at and above 1.1.7 can read both versions, but will default to writing and reading 2<ref name="12vs" />. There is nothing in the stream to indicate the "protocol version"; users must decide on it (fill this in with heuristics).

== Specifications ==
* [https://www.cs.princeton.edu/courses/archive/fall97/cs461/jdkdocs/guide/serialization/spec/protocol.doc.html Protocol version 1]
* [https://docs.oracle.com/en/java/javase/12/docs/specs/serialization/protocol.html Protocol version 2]

== References ==
<references />

[[Category:Sun]]

@@ Line 12: / Line 12: @@
 * an integer field in the header called "STREAM_VERSION" or just "version", which has been 5<ref name="v19303">https://www.cs.princeton.edu/courses/archive/fall97/cs461/jdkdocs/guide/serialization/spec/protocol.doc.html#9303</ref><ref name="12tsc">https://docs.oracle.com/en/java/javase/12/docs/specs/serialization/protocol.html#terminal-symbols-and-constants</ref> since at least JDK 1.1.4<ref>https://www.cs.princeton.edu/courses/archive/fall97/cs461/jdkdocs/</ref>, released between 1997 and 1998<ref name="wvh" />, meaning that it has had the value of 5 for almost all of the format's existence;
 * and the "version" not of the Object Serialization format, but of whatever format is built on top of it<ref>https://docs.oracle.com/en/java/javase/12/docs/specs/serialization/version.html</ref>.
-The "protocol version" can be either 1 or 2. The second version was made standard in the Java platform in version 1.2<ref name="12vs" /> in December 1998<ref name="wvh" />. Java versions at and above 1.1.7 can read both versions, but will default to writing and reading 2<ref name="12vs" />. There is nothing in the stream to indicate the "protocol version"; users must decide on it (fill this in with heuristics).
+The "protocol version" can be either 1 or 2. The second version was made standard in the Java platform in version 1.2<ref name="12vs" /> in December 1998<ref name="wvh" />. Java versions at and above 1.1.7 can read both versions, but will default to writing and reading 2<ref name="12vs" />. There is nothing in the stream to indicate the "protocol version".
 == Identification ==

@@ Line 10: / Line 10: @@
 There are three different things in or attributes of a Java Object Serialization stream that are referred to by "version":
 * "protocol version", which corresponds to the usual meaning of "version";
-* an integer field in the header called "STREAM_VERSION" or just "version", which has been 5<ref>https://www.cs.princeton.edu/courses/archive/fall97/cs461/jdkdocs/guide/serialization/spec/protocol.doc.html#9303</ref><ref>https://docs.oracle.com/en/java/javase/12/docs/specs/serialization/protocol.html#terminal-symbols-and-constants</ref> since at least JDK 1.1.4<ref>https://www.cs.princeton.edu/courses/archive/fall97/cs461/jdkdocs/</ref>, released between 1997 and 1998<ref name="wvh" />, meaning that it has had the value of 5 for almost all of the format's existence;
+* an integer field in the header called "STREAM_VERSION" or just "version", which has been 5<ref name="v19303">https://www.cs.princeton.edu/courses/archive/fall97/cs461/jdkdocs/guide/serialization/spec/protocol.doc.html#9303</ref><ref name="12tsc">https://docs.oracle.com/en/java/javase/12/docs/specs/serialization/protocol.html#terminal-symbols-and-constants</ref> since at least JDK 1.1.4<ref>https://www.cs.princeton.edu/courses/archive/fall97/cs461/jdkdocs/</ref>, released between 1997 and 1998<ref name="wvh" />, meaning that it has had the value of 5 for almost all of the format's existence;
 * and the "version" not of the Object Serialization format, but of whatever format is built on top of it<ref>https://docs.oracle.com/en/java/javase/12/docs/specs/serialization/version.html</ref>.
 The "protocol version" can be either 1 or 2. The second version was made standard in the Java platform in version 1.2<ref name="12vs" /> in December 1998<ref name="wvh" />. Java versions at and above 1.1.7 can read both versions, but will default to writing and reading 2<ref name="12vs" />. There is nothing in the stream to indicate the "protocol version"; users must decide on it (fill this in with heuristics).
 == Specifications ==