Creating XML files from Java

[Nepomuk]

Hi there!
I'm trying to create a XML file from within Java. After doing a bit of research, I'm quite confused - there seem to be many, many classes in the standard libraries (plus many more outside), that somehow deal with XML, but I don't know, which ones would be right for me. Here's what I want to do:

I want to read TXT files (no problem with that), extract the right information (still no problem so far) and then create an XML file, that holds the data I just extracted from the TXT files. I have designed a structure for my XML files, now I need the computer to create them for me.

So, which classes would you recommend and can you either give me an example of how to use them or direct me to a tutorial with a good example?

Greetings,
Nepomuk

[r035198x]

I'd suggest that you start with JAXP

[Nepomuk]

I'd suggest that you start with JAXP

Thanks for the link, but I'm not sure, it's what I'm looking for. Here's why:

The Java API for XML Processing [...] is one of the Java XML programming APIs. It provides the capability of validating and parsing XML documents.

I'm not trying to validate or parse any XML documents (at the moment), I'm trying to create them. I also checked at saxproject.org and it seems, they only read files instead of creating them in their examples. Also, I had a look through the org.xml.sax library with Eclipse and couldn't find anything about writing.

Have I just checked the wrong places or do I need something else? If so, what?

Thanks,
Nepomuk

*EDIT* I just found the interface XMLStreamWriter - might that be the right path to be looking at? Or maybe the XMLEncoder? (Although I wasn't planning to use JavaBeans, but it might be a good idea - I'll have to think about it.)

*EDIT 2* OK, it probably isn't the XMLStreamWriter , as I need something, that's available in JRE 1.4.x, and that doesn't seem to. Still checking out the XMLEncoder.

[Nepomuk]

OK, I guess I'll probably just use a FileWriter. If anyone has a better suggestion, please come forward with it!

Greetings,
Nepomuk

[blazedaces]

First understand how xml is read... and then write it.

Use a printWriter and write println("<" + name + attribute + ... + ">"), then print(" ") <-- tab, then write the next one, and when you're closing that specific bracket use println("</" + name + attribute + ... + ">").

Perhaps you could just create methods that automatically did that, like openBracket(nam e, attribute = "", other attribute = "") and closeBracket(na me, attribute = "", other attribute = "")?

Good luck,
-blazed

[Nepomuk]

First understand how xml is read... and then write it.

Thanks, but as I said, I've already created the structure. I've even written a quite long XML file in that format by hand, but now I want the computer to do that for me.

Use a printWriter and write...

As I said, I guess I'll use a FileWriter (OK, a PrintWriter ^^), but thanks for going in to more detail. :-D

Perhaps you could just create methods that automatically did that, like openBracket(nam e, attribute = "", other attribute = "") and closeBracket(na me, attribute = "", other attribute = "")?

Well, it would be more like[code=java]public void startTag(String name, String[] attributes, String[] values);
// can't think of a more elegant way that's worth the effort to have attributes and their values at the moment
public void endTag(String name);[/code]or similar, but of course I could do it your way.

Good luck,
-blazed

Thanks! :-)

Greetings,
Nepomuk

[JosAH]

I once crafted a little extension class to the Writer class that could wrap another
Writer. It had three additional methods: push(String), pushpop(String) and pop().
Internally it had a stack of tags, the push() method wrote the opening tag and
its optional arguments and pushed it on the stack. <tag ...>

The pushpop() thing did the same but closed the tag immediately <tag .../> and
that last method (I don't remember whether or not it took a parameter) popped
a tag from that stack <tag/>

It worked for the folks I wrote it for ;-) Nowaday I would use a bit of varargs for
the push() and pushpop() methods.

kind regards,

Jos

[rajujrk]

I think below code will help you..

[ spoonfeeding code deleted - moderator ]

[JosAH]

@rajujrk: read the 'Help' link near the top of this page; we don't hand out boilerplate
code here. We try to help people understand instead of spoonfeeding them.
Also, if you have to post snippets of code use the [code] ... [/code] tags.

kind regards,

Jos (moderator)

[kokababu]

If you want to create xml in java you can use DOM api or stAX api.

[Nepomuk]

OK, maybe I should say that I've solved the issue by writing a wrapper to the BufferedWriter class. However, it doesn't use a stack as Jos' one did. As the structure of my file is quite simple, I could easily write few functions to do most of my work. Of course, anyone who wants to suggest I rewrite the code in a much easier way, feel free to do so! :-D

Just a suggestion, maybe someone would enjoy writing an article about XML and Java? How to read and write XML files, JAXB, JAXP and whatever they're all called. I'm sure, that would help people a great deal ever so often. I'd do it myself if a) I wasn't so busy, b) I hadn't already started 2 articles that I still have to complete and c) I knew enough about it.

Greetings,
Nepomuk