Harmony - Revision history

JaroslavTulach: /* JDK9 */

JaroslavTulach — Mon, 14 Aug 2017 07:50:10 GMT

JDK9

←Older revision		Revision as of 07:50, 14 August 2017
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	Is that the long awaited happy end? Does not it arrives a bit too late?		Is that the long awaited happy end? Does not it arrives a bit too late?

-	=== [[JDK]]9 ===	+	=== [[JDK]]9: [[Jigsaw]] ===

	2017 update: The [[JDK]]8 profiles came and went on almost unnoticed. [[I]] am not aware of much/any developers that would have actively changed their libraries to match [[JDK]]8 profile 1, etc. However this year it seems that [[Jigsaw]] is coming and the stress to re-target libraries to run with ''java.base'' slimmed down [[JDK]] may appear again. At least the [[Graal]] compiler project needs that and [[I]] spent last few weeks fighting with various problems including our use of [[PropertyChangeListener]].		2017 update: The [[JDK]]8 profiles came and went on almost unnoticed. [[I]] am not aware of much/any developers that would have actively changed their libraries to match [[JDK]]8 profile 1, etc. However this year it seems that [[Jigsaw]] is coming and the stress to re-target libraries to run with ''java.base'' slimmed down [[JDK]] may appear again. At least the [[Graal]] compiler project needs that and [[I]] spent last few weeks fighting with various problems including our use of [[PropertyChangeListener]].

JaroslavTulach: Property change listener

JaroslavTulach — Mon, 14 Aug 2017 07:49:49 GMT

Property change listener

←Older revision		Revision as of 07:49, 14 August 2017
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	Is that the long awaited happy end? Does not it arrives a bit too late?		Is that the long awaited happy end? Does not it arrives a bit too late?
		+
		+	=== [[JDK]]9 ===
		+
		+	2017 update: The [[JDK]]8 profiles came and went on almost unnoticed. [[I]] am not aware of much/any developers that would have actively changed their libraries to match [[JDK]]8 profile 1, etc. However this year it seems that [[Jigsaw]] is coming and the stress to re-target libraries to run with ''java.base'' slimmed down [[JDK]] may appear again. At least the [[Graal]] compiler project needs that and [[I]] spent last few weeks fighting with various problems including our use of [[PropertyChangeListener]].

JaroslavTulach: /* Fragmentation of Java */

JaroslavTulach — Mon, 14 Aug 2017 07:43:16 GMT

Fragmentation of Java

←Older revision		Revision as of 07:43, 14 August 2017
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	=== Fragmentation of [[Java]] ===		=== Fragmentation of [[Java]] ===

-	Since the early days of [[Java]] [[Sun]] was afraid of fragmentation of [[Java]] (and fought hard against [[Microsoft]] to prevent that) and [[Harmony]] was ~~resulting~~ to exactly that. To remain in control [[Java]] [[Sun]] took its last chance and finally decided to create an [[OpenJDK]] project - its own open source version of [[Java]]. The start was not fast, but slowly other vendors ([[IBM]] and [[Apple]]) got convinced to contribute to [[OpenJDK]] rather than [[Harmony]] (which [[IBM]] originally supported significantly). After [[IBM]] left [[Harmony]], the project vanished. The unity was here again and the fragmentation was gone...	+	Since the early days of [[Java]] [[Sun]] was afraid of fragmentation of [[Java]] (and fought hard against [[Microsoft]] to prevent that) and [[Harmony]] was going to do exactly that. To remain in control [[Java]] [[Sun]] took its last chance and finally decided to create an [[OpenJDK]] project - its own open source version of [[Java]]. The start was not fast, but slowly other vendors ([[IBM]] and [[Apple]]) got convinced to contribute to [[OpenJDK]] rather than [[Harmony]] (which [[IBM]] originally supported significantly). After [[IBM]] left [[Harmony]], the project vanished. The unity was here again and the fragmentation was gone...

	...up until [[Google]] came with [[Android]] (based on some fork of [[Harmony]]) and made its [[Dalvik]] [[VM]] the most successful mobile operating system. So successful that [[Android]] almost became synonym for [[Java]] (ask [[Android]] developers whether they speak [[Java]] and they will say yes, even it is not de-jure true).		...up until [[Google]] came with [[Android]] (based on some fork of [[Harmony]]) and made its [[Dalvik]] [[VM]] the most successful mobile operating system. So successful that [[Android]] almost became synonym for [[Java]] (ask [[Android]] developers whether they speak [[Java]] and they will say yes, even it is not de-jure true).

JaroslavTulach: /* Incomplete and Mostly Wrong History of Open source Java Implementations */

JaroslavTulach — Mon, 14 Aug 2017 07:42:13 GMT

Incomplete and Mostly Wrong History of Open source Java Implementations

←Older revision		Revision as of 07:42, 14 August 2017
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	The project had to be very careful who to hire. Anyone who might have seen a line of original [[Sun]]'s [[Java]] implementation (even if it was not open source, there was a ''src.zip'' in the [[JDK]] root directory) had to be ruled out.		The project had to be very careful who to hire. Anyone who might have seen a line of original [[Sun]]'s [[Java]] implementation (even if it was not open source, there was a ''src.zip'' in the [[JDK]] root directory) had to be ruled out.

-	Another problem was to verify whether the implementation is or is not compliant? The usual style is to run a [[TCK]] - however the [[TCK]] was not [[open source]] either and [[Sun]] wanted a payment for access to the official [[TCK]]. [[Apache]] Foundation rejected to pay anything (which at the end resulted in them stepping out of [[JCP]] committee years later). Rather than that they wrote a set of tests from scratch (based on reading the official [[API]] [[Javadoc]]) and they run them on both [[Java] implementations [[Harmony]] and [[Sun]]'s [[Java]]. Whenever the test results diverged, they fixed [[Harmony]] ([[chapter 15]] discusses this testing approach more deeply and shows how powerful it can be if mixed with [[RandomizedTests]]).	+	Another problem was to verify whether the implementation is or is not compliant? The usual style is to run a [[TCK]] - however the [[TCK]] was not [[open source]] either and [[Sun]] wanted a payment for access to the official [[TCK]]. [[Apache]] Foundation rejected to pay anything (which at the end resulted in them stepping out of [[JCP]] committee years later). Rather than that they wrote a set of tests from scratch (based on reading the official [[API]] [[Javadoc]]) and they run them on both [[Java]] implementations [[Harmony]] and [[Sun]]'s [[Java]]. Whenever the test results diverged, they fixed [[Harmony]] ([[chapter 15]] discusses this testing approach more deeply and shows how powerful it can be if mixed with [[RandomizedTests]]).

	But of course, when there is enough tests? Never. So certain parts of the [[Harmony]] implementation diverged a lot from the original as they there was really much less tests than necessary and even the original documentation was more than poor (like in case of [[Swing]]).		But of course, when there is enough tests? Never. So certain parts of the [[Harmony]] implementation diverged a lot from the original as they there was really much less tests than necessary and even the original documentation was more than poor (like in case of [[Swing]]).

JaroslavTulach at 14:49, 12 August 2013

JaroslavTulach — Mon, 12 Aug 2013 14:49:03 GMT

←Older revision		Revision as of 14:49, 12 August 2013
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	[[wikipedia:Apache_Harmony\|Harmony]] is second (after [[GNU Classpath]]) major re-implementation of [[Java]] libraries. These days it does not seem to be actively developed in spite of being used as a base for [[Android]] [[API]]s.		[[wikipedia:Apache_Harmony\|Harmony]] is second (after [[GNU Classpath]]) major re-implementation of [[Java]] libraries. These days it does not seem to be actively developed in spite of being used as a base for [[Android]] [[API]]s.

-	== Incomplete and Wrong History of [[Open source]] [[Java]] Implementations ==	+	== Incomplete and Mostly Wrong History of [[Open source]] [[Java]] Implementations ==

	There was a strong push to make [[Java]] open source which [[Sun]] was rejecting for a long time. As a result [[Apache]]'s [[Harmony]] project was established. Its goal was to write a compliant implementation of [[Java]] from scratch under the [[Apache]] open source license.		There was a strong push to make [[Java]] open source which [[Sun]] was rejecting for a long time. As a result [[Apache]]'s [[Harmony]] project was established. Its goal was to write a compliant implementation of [[Java]] from scratch under the [[Apache]] open source license.

JaroslavTulach at 14:44, 12 August 2013

JaroslavTulach — Mon, 12 Aug 2013 14:44:01 GMT

←Older revision		Revision as of 14:44, 12 August 2013
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	[[wikipedia:Apache_Harmony\|Harmony]] is second (after [[GNU Classpath]]) major re-implementation of [[Java]] libraries. These days it does not seem to be actively developed in spite of being used as a base for [[Android]] [[API]]s.		[[wikipedia:Apache_Harmony\|Harmony]] is second (after [[GNU Classpath]]) major re-implementation of [[Java]] libraries. These days it does not seem to be actively developed in spite of being used as a base for [[Android]] [[API]]s.
		+
		+	== Incomplete and Wrong History of [[Open source]] [[Java]] Implementations ==
		+
		+	There was a strong push to make [[Java]] open source which [[Sun]] was rejecting for a long time. As a result [[Apache]]'s [[Harmony]] project was established. Its goal was to write a compliant implementation of [[Java]] from scratch under the [[Apache]] open source license.
		+
		+	The project had to be very careful who to hire. Anyone who might have seen a line of original [[Sun]]'s [[Java]] implementation (even if it was not open source, there was a ''src.zip'' in the [[JDK]] root directory) had to be ruled out.
		+
		+	Another problem was to verify whether the implementation is or is not compliant? The usual style is to run a [[TCK]] - however the [[TCK]] was not [[open source]] either and [[Sun]] wanted a payment for access to the official [[TCK]]. [[Apache]] Foundation rejected to pay anything (which at the end resulted in them stepping out of [[JCP]] committee years later). Rather than that they wrote a set of tests from scratch (based on reading the official [[API]] [[Javadoc]]) and they run them on both [[Java] implementations [[Harmony]] and [[Sun]]'s [[Java]]. Whenever the test results diverged, they fixed [[Harmony]] ([[chapter 15]] discusses this testing approach more deeply and shows how powerful it can be if mixed with [[RandomizedTests]]).
		+
		+	But of course, when there is enough tests? Never. So certain parts of the [[Harmony]] implementation diverged a lot from the original as they there was really much less tests than necessary and even the original documentation was more than poor (like in case of [[Swing]]).
		+
		+	Clearly re-implementing something as huge as whole '''JRE''' was behind capabilities of anyone. The biggest success of [[Harmony]] (prior to become a base for [[Android]]) was the ability to launch [[Eclipse]] (due to its distinctive refusal of [[Swing]] and usage of own proprietary, but open source [[SWT]]).
		+
		+	=== Fragmentation of [[Java]] ===
		+
		+	Since the early days of [[Java]] [[Sun]] was afraid of fragmentation of [[Java]] (and fought hard against [[Microsoft]] to prevent that) and [[Harmony]] was resulting to exactly that. To remain in control [[Java]] [[Sun]] took its last chance and finally decided to create an [[OpenJDK]] project - its own open source version of [[Java]]. The start was not fast, but slowly other vendors ([[IBM]] and [[Apple]]) got convinced to contribute to [[OpenJDK]] rather than [[Harmony]] (which [[IBM]] originally supported significantly). After [[IBM]] left [[Harmony]], the project vanished. The unity was here again and the fragmentation was gone...
		+
		+	...up until [[Google]] came with [[Android]] (based on some fork of [[Harmony]]) and made its [[Dalvik]] [[VM]] the most successful mobile operating system. So successful that [[Android]] almost became synonym for [[Java]] (ask [[Android]] developers whether they speak [[Java]] and they will say yes, even it is not de-jure true).
		+
		+	There was the lawsuit after [[Oracle]]'s acquisition of [[Sun]] in which [[Google]] defended [[Android]] successfully. Looks like legal actions are not going to prevent fragmentation. But as fragmentation is real and hurts developers a lot, why not take a technical action to fight with it?
		+
		+	=== [[JDK]]8 Profiles: The end of fragmentation ===
		+
		+	After a long struggle it seems that the fragmentation may be gone with [[JDK]]8 (plus if we wait two or three years more). [[JDK]]8 is going to come up with ''profiles'' and the smallest one does not include [[Swing]], neither [[CORBA]], neither bloated [[XML]] parser and other crap which made [[Java]] so heavy weight (instead of [[modular]]) over the years. The smallest profile consists of about three thousand classes. That is something that can be re-implemented. But even better - it is something that can be re-used! As such I'd expect that in future the ''compact1 profile'' will be the [[JDeveloper#Common Ground\|Common Ground]] that will unify various [[Java]]-like solutions and let them become real [[Java]] and prevent fragmentation forever.
		+
		+	Is that the long awaited happy end? Does not it arrives a bit too late?

JaroslavTulach: New page: Harmony is second (after GNU Classpath) major re-implementation of Java libraries. These days it does not seem to be actively developed in spite of bei...

JaroslavTulach — Tue, 08 May 2012 18:50:40 GMT

New page: Harmony is second (after GNU Classpath) major re-implementation of Java libraries. These days it does not seem to be actively developed in spite of bei...

New page

[[wikipedia:Apache_Harmony|Harmony]] is second (after [[GNU Classpath]]) major re-implementation of [[Java]] libraries. These days it does not seem to be actively developed in spite of being used as a base for [[Android]] [[API]]s.