I am quite new to ant and have been looking at the tasks. I am trying to generate an xml file. Do I need to call an external process or does ant have some way to do this? It could be as simple as sending a string to a txt file and saving it as a .xml. Is it possible?
When you have to deal with any kind of XML processing within in your ant workflow, the xmltask is strongly recommended. Very detailed documentation and good support. All you need beside that is some XPATH knowledge. Here => another helpful article
The correct answer depends upon what you're actually trying to do.
You could create a tiny xml document using echo task and argument replacement, but that gets hard to maintain very quickly.
If your goal is to generate an XML document that is mostly boilerplate with a couple of values substituted, then you should look at creating a template document and then using the Copy with filtering task.
If you need to modify the structure of the document depending upon data from Ant (or gathered from somewhere else) then using the xslt task is going to be a better fit. The problem with XSLT is that it is not always straight-forward to use (XSLT uses functional programming, not procedural programming).
You may find that the correct answer is to write your own Ant task that will do exactly what you want, just the way you want it.
If you can better describe what you're trying to achieve, I'm sure someone will be happy to provide a more precise answer.
You can use the Replace task to replace a given string in a template, and save it as xml.
A simple example, as seen in the ant documentation:
<replace file="${src}/index.html" token="###" value="wombat"/>
I used it to replace a constant #version# by the actual build identifier in a java project, for example.
If you want to do more complex processing, you should look at the XSLT task. Foe example, to generate documentation, with the date replace in the output, you can use something like:
<xslt basedir="doc" destdir="build/doc"
extension=".html" style="style/apache.xsl">
<param name="date" expression="07-01-2000"/>
</xslt>
You could do that, although it seems to me more like something you would want to script beforehand, or something that you could call out to from Ant.
The task would be:
<echo file="my.xml"><!--put escaped xml here--></echo>
This is of course going to be tedious since everything has to be escaped, but you can do it.
Related
Using Java to write xml strikes me as perhaps not the best match. Is this just because it's new and unfamiliar, perhaps?
Rather than generating JAXB source code from xml might it not be more flexible to work with xml files directly? What I mean is, cannot the middle-man be cut out?
If JAXB can generate source code for the class files to manipulate xml might there a tool which uses JAXB without creating concrete boiler-plate?
If there's simply a mis-match making this impossible please elaborate. Or, if it's simply out of reach, what are the obstacles?
I'm a quite new to java world and I have a requirement of generating an .xml file from an .xsd file
I did some research and found that 'jaxb' could do it. And I found some example too, but the problem is, almost all the examples uses 'xjc' tool to do this. But I want a way to do this through my java code.
Os this possible?
if yes, I'm thinking something like this, from my java code
load the .xsd file
generate the .xml
save the .xml file
Can someone direct me to a good resource and or tell me if my thinking is wrong
I've had good experiences using XMLBeans, however I've always had the XSD available at compile time. It integrates nicely with Maven (plus potentially other build systems). The compilation produces a series of Java classes that can be used to construct an XML document that conforms to the XSD or process an XML file you've received.
You can potentially do some runtime processing of an XSD using the org.apache.xmlbeans.XmlBeans.compileXsd class, but I've never experimented with it. Just seen a reference from an FAQ.
I think the main problem is that to do it in a clean way you should have classes reflecting your xsd. Xsd defines a data model, so the important part is to recreate it with classes. If you want to do it dynamically it could be rather difficult. If you want to do it at compile time- jaxb is the way to go. There is very interesting article talking about problems related with parsing xml (it goes from a different perspective than you describe), but I think there is a wealth of knowledge to be learned from here:
http://elegantcode.com/2010/08/07/dont-parse-that-xml/
I need to parse a large (>800MB) XML file from Jython. The XML is not deeply nested, containing about a million relevant elements. I need to convert these elements into real objects.
I've used nu.xom.* successfully before, but now that I've switched from Java to Jython, the library fails with the following message:
The parser has encountered more than
"64,000" entity expansions in this
document; this is the limit imposed by
the application.
I have not found a way to fix this, so I probably have to look for another XML library. It could be either Java or Jython-compatible Python and should be efficient. Pythonic would be great, nu.xom.* is simple but not very pythonic. Do you have any suggestions?
Sax is the best way to parse large documents.
Sounds like you're hitting the default expansion limit.
See this note:
http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4843787
You need to set System property "entityExpansionLimit" to change
the default.
(added) see also the answer to this question.
Try using the SAX parser, it is great for streaming large XML files.
Does jython support xml.etree.ElementTree? If so, use the iterparse method to keep your memory size down. Read this and use elem.clear() as described.
there is a lxml python library, that can parse large files, without loading data to memory.
but i don't know if i jython compatible
My target is to assemble a static web site that has a lot of repeating code. Now, I could use JSP includes for that purpose. But the site will be modified infrequently and under very heavy load, also using features like gzip and I don't need the complications.
My idea is to put up a build process with some tool like ant, That build process will concatenate all HTML pieces, preprocess HTML, JS, CSS with minifier and finally apply gzip.
I want an XML configuration that will define the parts that need to go in every html page and their order.
I need advice on ant or any similar tool; how to approach the configuration, any external tools that will help? Any suggestions are much appreciated.
XSLT is perfectly suited to transform XML into another format like HTML.
You can download Apache Xalan to give it a try. Ant has support for XSLT processing.
In the java world, you can take a look at Apache Forrest, which precisely do that kind of things.
In other worlds, there also exist webgen, which is a competent Ruby site builder.
I also vaguey remember there are other alternatives, but i can't find back their name.
I writing a dynamic HTML parsers functionality.
I will want to modify existing parsers and also would want to add more parsers (I expect parsers will be modified as sites a remodified and new parsers will be needed for new sites).
I started writing a generic functionality which use a XML with conditions and rules for each site but as this works fine for now, I'm pretty sure it will need constant modifications...
The parsers will parse and write the data to a DB.
My application runs on JBOSS 4.
Any known best practice for that?
Thanks,
Rod
Thanks for your answer. Maybe I was unclear. I realized that imm. from the rate my question got. What I am writing feature that manage parsers execution. Each parser will parse a different text document structure. Documents structure might change from time to time and more new structured document will be added to be parsed. I dont want to recompile build deploy my application for each arser change.
I want to manage the execution of each parser as theymight be executed in parralel or according to execution rules.
Does Using Java ScriptingEngine might be a good option?
There are lots of ways to have some code that can be modified without redeploying. Using groovy scripts to do the parsing is one. Is is a rather simple matter to check to see if the script has been modified and automatically reload it.
The design sounds convoluted to me, but IFF you prove to yourself there's not a much simpler way to accomplish the same task, you may want a rules engine like Drools...