Is it true that the only configuration file I need to bother with is pom.xml ?
It seems to me that Java guys live xml more than any other stuff,is that true?
Maven uses XML for POM files because XML is a good choice for describing things ... and a POM file is a description of a project. I supposed that the Maven implementors could have invented a custom language, but then lots of people would have complained about having to learn another language syntax.
It would make no sense to express Maven POM files in some kind of scripting language because they are not "scripts" in any recognizable sense.
It seems to me that Java guys live xml more than any other stuff,is that true?
No. "Java guys" use all sorts of technologies for configuring things: XML, JSON, properties files, databases, bespoke languages, you name it someone has used it.
If your problem is that you hate using XML, either:
get over it,
get an editor that hides the XML syntax from you,
use (shudder) Make,
use (whimper) build scripts written in some clunk old scripting language, or
go away and implement a better solution.
But I'll stick with Maven, thanks.
Is it true that the only configuration file I need to bother with is pom.xml ?
Yes, Maven uses a pom.xml file to describe a project's medata and extend Maven's behavior, which also known as the Project Object Model (POM) file.
Maven will also look by default for a per user configuration file in ~/.m2/settings.xml but this file is optional.
Why doesn't maven use scripts for this kind of job, I don't see xml has any advantage here, which is why I don't like ant
What should Maven have used in 2002 if not XML? Makefiles? In my opinion, XML was and still is a very decent choice for a declarative Project Object Model. Yes XML is verbose but it is perfect for the job and allows to benefit from nice things like validation, transformation, code completion which seem important to me.
Now, nothing forces you to use Maven if you don't like it and feel free to use Gradle or Gant or Buildr (if the size of their communities is not a concern).
Just in case, note that Maven 3 offers polyglot support (see this post and this one) but as I said, writing a pom in Groovy, YAML, etc doesn't only have advantages (e.g. validation).
You probably want to give some attention to the settings.xml file too. However, for the most part you are correct, everything is in the pom.xml
Related
How to make maven/gradle package change what it’s exported by scope? Is it possible?
Like, use like this
<dependency>
<groupId>org.blahblah</groupId>
<artifactId>anything</artifactId>
<version>5.8</version>
<scope>test<scope/>
</dependency>
To get different binaries by use this another way
[...]
<scope>compile<scope/>
[...]
yes and no - sort of.
The general guideline is to create one artifact per pom.xml - most tools work quite nice with this concept. As soon as you go beyond sometimes funky stuff happens. Changing the jar only by scope isn't possible afaik. It would also confuse people a lot. And probably will make troubleshooting very difficult.
But there is a workaround. As you mentioned tests: the jar plugin allows you to export the classes in src/test/java as test-jar and use that as dependency specifying a type.
See How to create a test-jar.
I assume the same mechanism with the type can be used for other things as well.
There is also the concept of classifiers (this is usually used for sources, javadoc and things like that). See this question.
While these things tend to work with maven on the command line, IDEs sometimes start to behave a bit weird if you push type and classifier usage too far.
I have a complex structure of maven module with involves some like 20 modules for a standard application. The standard application is also supposed to contain spring xml files and packages folder setup from the start. Right now we are copying a example application and change the name all over it. But this seems like a lot of unnecessary work. I'm wondering what software would be best to use generate this.
I saw that maven had something for this called archetype but i'm not find much documentation and example on how to use it. Maybe there is better tool for this task.
I'm using Maven Java API to configure Maven in a custom Java project.
In particular I need to configure some Maven settings, among which there are proxy settings.
How can i do this? I googled a lot, but I found no examples on how to use Maven from Java.
Can You give me an example or a guide, a snippet of code, whatever you want to clarify HOW TO USE (AND CONFIGURE) Maven by Java API, i.e from Java code?
I found this maven reference, but what do I specifically need?
Thanks in advance.
I've already seen this question, but unfortunately there is no mention on how to edit settings.xml from maven api, I suppose it is possible, but I'm not sure of it, so I asked a new question, wider than that one, how can I manage Maven from Java? settings, run, properties, whatever... is it possible?
For example, about settings management, I found this API maven-settings, it can be useful? It's "read-only" API? I guess it isn't, but I've found no way how to "write" modifications to file, there are no examples on how to use it.
Well, yes, you are a bit crazy. You can take a look at some plug-ins which modify pom.xml files. For example, the versions-set facility shown here:
http://www.mojohaus.org/versions-maven-plugin/set-mojo.html
The source code for that plug-in will show you how to modify pom.xml files, but you also want to modify the settings.xml file.
All of these files are XML. Basically, you want to obtain a DOM for the .xml file. So, you can use generic XML tools to (1) read the file, (2) modify the document model, (3) write the data back to disk.
Note well: Maven caches the .xml files. You have to stop the maven executable and restart it to force it to re-read the .xml files. It sounds like you'll probably be doing this as a matter of course. :-)
I am new to maven and Jcodemodel. I am trying to create an archetype which will accept the wsdl and generate the code. I need to create java code for implementation class file by implementing the interface. I need to use JCodeModel to generate java code. But I am new to JCode. How to use Jcodemodel inside Maven archetype to generate java code?
Kindly, guide me
Maven will build your projects and automate some aspects of managing the builds and the project; but, it will not decide for you what the project does, or how to go about writing the project.
You might need to write Java code that (because you mentioned a WSDL) runs as a web service. That web service apparently should accept "something" and reply back with "something". It is a guess (this is a very vague question), that the something it should accept is some sort of description of a Java class, and the something it should reply will be either Java source code, or a compiled java class.
In either case, the project can be managed by Maven, meaning that Maven will compile, test, and package your project. In certain cases, it will also deploy it (if you configured Maven to do so).
Now if you want Maven to actually accept the WSDL and generate the code, then what Maven will build will be static, meaning that the "generated" code will not be able to change after Maven completes the build. You can; however, build the "next" version which might change. If this scenario sounds more like what you had in mind, then your "source" would be a static file, and the "built project" would be the source code or the object code corresponding to the source.
Without more direction, this is probably the best guide you are going to get. It is just too vague a question, covering too much ground to say much definitively. You also seem to lack a lot of knowledge in a lot key places simultaneously; perhaps the best solution is to identify what you will likely need to brush up on, order those by "what needs what" and start with the element that depends on nothing else.
Sorry for such question since it is more my duty to search for it, but I looked everywhere and didn't find answer for it.
Is it possible to get all apache commons components in one jar or there is no such archive?
No, we don't have a "all-of-commons" jar (nor should we). It'd be large, and the functionality would be a pretty bizarre mix. You could always (attempt) to create one yourself, but you might need to do some shading if there's any version mis-matching.
I highly doubt it. It makes no sense to combine such a broad array of functionality into a single jar. Most of the projects have nothing to do with one another and it is unlikely to require them all for a single application.
You can download the whole of spring in one hit. I have seen project "using" Spring, not as a container but as a way of including lots of libraries which can work together. i.e. no actual Spring class is used.
However I suggest you use a proper dependency management tool such as maven and you shouldn't need to download a jar yourself ever again. ;)
A good web site for finding dependencies is http://mvnrepository.com/ which have the XML you need to add to your pom.xml to get any version of most JAR you need.