JAXB tutorial: XML parsing with style

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toxmeister

JAXB tutorial: XML parsing with style

in Share your Work • 2 years ago

I've finally put up a short and long overdue tutorial & example sketch using the awesome JAXB framework to make working with XML a thousand times more fun & easy to use than the built-in XML library:

http://wiki.processing.org/w/XML_parsing_with_JAXB

When I have a bit more time I'll also include another example about saving your data as XML in a similarly easy way...

Hth!

http://postspectacular.com | http://toxiclibs.org

Replies(14)

cedrickie..

Re: JAXB tutorial: XML parsing with style

2 years ago

fantastic! thanks a lot for adding it to the Wiki

PhiLho

Re: JAXB tutorial: XML parsing with style

2 years ago

Moving to the Exhibition section, as it isn't a programming question.
Well done, that's something I vaguely planned to do for quite some time, but never managed to get that out... (EDIT: actually I aimed at documenting only the Stax method, so there is still room for that...)
I think Processing should use that (built-in XML support from Java), dropping the current XML library internals (perhaps keeping the current API for compatibility and simplicity, but possibly extending it), as it would allow to read other encodings, will have better support of all XML standards (namespace...), etc.

mbraendle

Re: JAXB tutorial: XML parsing with style

2 years ago

I don't think that the internal XML should be dropped, because of compatibility issues with processingjs.

PhiLho

Re: JAXB tutorial: XML parsing with style

2 years ago

I don't see how it would be problematic. By definition, internal implementation is hidden behind the API itself.

mbraendle

Re: JAXB tutorial: XML parsing with style

2 years ago

It would be problematic since the XML parsing functions would need to be rewritten if one would like to migrate a Processing project to processingjs.It's a crossplatform issue. Remember that many mobile device browsers don't support neither Java nor Flash.

PhiLho

Re: Re: JAXB tutorial: XML parsing with style

2 years ago

Again, in my proposed change, the API, ie. the way programs use the XML functions, wouldn't change (just would be extended).
I don't know the official position here, but Processing.js is, AFAIK, not an official sub-project of Processing.org.
I don't expect Processing.org to restrict their improvements and innovations to remain compatible with the JS version. It would be the task of the PJS team to catch up.
Note that there are already some changes that might be not compatible (unverified) with PJS, like the support of Java 1.5 syntax.

joehao

Re: JAXB tutorial: XML parsing with style

2 years ago

I want to use JAXB to deal with my xml file, and then convert to a processingjs project. Has anyone done this before and how was it?

toxmeister

Re: JAXB tutorial: XML parsing with style

2 years ago

Thanks & glad you found it useful! I haven't done a single project without JAXB in the past 3 years, but until v. recently it's only been possible outside the PDE. Now with annotation support included (thanks Ben!), I might also resurrect my controlP5magic library...

@joehao If you are already working with or going to use JavaScript, please just use the JSON format instead of XML! The former already IS native JavaScript and doesn't require any parsing. To help you get started with JSON also on the original Processing/Java side, I'd also included a link to the Jackson library in the tutorial above. It's v. similar in approach to JAXB but doesn't use XML...

As to @mbraendle's compatibility comment: To anyone who's ever worked with JS before, alone the recommendation of using the original processing.xml syntax to deal with XML in an JavaScript environment is nothing less than silly! I think this highlights the entire slightly misguided nature of the current ProcessingJS approach to create this weird hybrid between a language layer originally sitting on top of Java (but trying to hide most of it) and now a JavaScript implementation which pretends to be a strongly-typed language (like Java) whereas pure JS would win hands down in terms of simplicity due to not having this constraint. In the PJS long term we would all so much more benefit from an equally, if not better designed, pure JS framework in the spirit of Processing, rather than focusing on 1:1 copy&paste compatibility as is currently being prioritised. What other aspect apart from reaching for carbon-copy compatibility made it possible that a switch of the underlying language, design context and deployment environment was not ever seen as an opportunity to challenge, adapt and improve the current design of Processing, but simply accept it as something perfect & unchangeable? We all should know that software always can & should be refactored wherever possible...

Anyhow, side tracking...

PhiLho

Re: JAXB tutorial: XML parsing with style

2 years ago

I agree with you, toxmeister.

Processing.js is a tour de force, and the positive side to its approach is to ease porting sketches from the regular Processing to the JS version. The negative side is that users might be expecting too much (trying to use libraries), and are lost when a difference (in behavior or syntax) is found.
I believe that "Processing implementations" can take the base design (simplicity of API) but must keep the look and feel of the implementing language: that's a good, fun way to learn this language after all!

afreise

Re: JAXB tutorial: XML parsing with style

2 years ago

Thanks for the nice tutorial. Just tried it myself and everything works as advertised.

BTW I assume with Java 6 the javax.xml.bind packages are included. Since I am still using Java 1.5, I needed to add the following packaged manually to my sketch as well: activation.jar, jaxb-api.jar, jaxb-impl.jar, jsr173_1.0_api.jar

Andreas

clankill3r

Re: JAXB tutorial: XML parsing with style

2 years ago

I get a error on this line in the MyUrl.java file:

public class MyURL {

The error is:

The public type MyUrl must be defined in its own file

Is it broken with the new processing or what?

i named the file MyUrl.java instand of MyURL.java

pinkydoe

Re: JAXB tutorial: XML parsing with style

1 year ago

Ancient thread but I used the tutorial. Thanks toxmeister.

I'm just wondering whether there is a way to feed the xml from a string which is already in memory, instead of loading a file.

The reason I ask is, I want to parse an xml string which is periodically updated. Now I can write the string to a file first and then parse that file, but that seems a bit redundant. Probably will make the program slow or cause unnecessary problems as well.

So is there a way to do that?

PhiLho

Re: JAXB tutorial: XML parsing with style

1 year ago

 config  =   (AppConfig)  context.createUnmarshaller().unmarshal(createInput("config.xml"));

createInput() makes an InputStream. What is nice with Java is that you can make an InputStream from a string, too. Try:
config = (AppConfig) context.createUnmarshaller().unmarshal(

new ByteArrayInputStream(yourXMLText.getBytes()));

(untested)

pinkydoe

Re: JAXB tutorial: XML parsing with style

1 year ago

Thanks phi.lho, I was trying something like that (but not exactly), didn't work. Will try it like this and see :D

EDIT: It works phi.lo, thanks. Much appreciated.

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