I've been using Gradle almost exclusively lately, but every now and again I have to dive back into our antiquated ant build system and figure out how to do something. Then I realize how little I know about ant and/or how difficult even some of the simplest tasks appear to be.
For example, I have a target that does some operation on a fileset:
<target name="some-operation">
<fileset dir="blah" id="stuff">
<filename name="**/*.txt" />
<not>
<filename name="**/foo/*" />
</not>
</fileset>
<!-- do some operations on "stuff" -->
</target>
Imagine this is in some old build system that multiple projects use. I want to exclude additional things in the fileset (let's say, files inside directory "bar", similar to "foo"), but since this is something multiple projects use, I can't just go putting my custom exclusions into the build system. I need some way to plug that additional fileset in (it could contain multiple exclusions).
What's the best way of doing this? I'm thinking I'll set a property in my build with the files to exclude, but the some-operation target will have to handle it gracefully when that property is missing. However, if I set a fileset to a property, I'm not quite sure how to get it excluded from the original fileset in some-operation.
Any ideas of the best/cleanest way to do this?
For reuse create a macrodef with nested element holding 1-n filesets for flexibility.
See this answer providing an example of macrodef using nested element.
Related
How to pass nested arguments from one ant target to another?
I need to pass a variable number of nested elements from one target to another.
I have a common file with all of my standard build tasks that's included in all of my projects.
I am adding a new custom task that takes a variable number of nested arguments
As a standard, all ant calls are made through the common file to ensure consistency of build style and logging.
Thus the new custom task and its nested child will be defined in the common script.
The project build script looks like this
<target name="projectBuild">
...
<ant target="_newFooTaskWrapper" antfile="commonFile">
<property name="_arg1" value="hello"/>
<property name="_arg2" value="world"/>
<nestedArg value="qux"/>
<nestedArg value="baaz"/>
...
<nestedArg value="AAAAA"/>
</ant>
...
</target>
The common script looks like this:
<target name ="_newFooTaskWrapper">
<echo message="Target _newFooTaskWrapper in project ${ant.project.name} from base directory ${basedir}"/>
<echo message="arg1 = ${_arg1}"/>
<echo message="arg2 = ${_arg2}"/>
<taskdef name="newFooTask" classname="org.foo.NewFooTask"/>
<typedef name="nestedArg" classname="org.foo.NewFooTask$NestedArg"/>
<newFooTask arg1="${_arg1}" arg2="${_arg2}">
<nestedArg value="qux"/>
<nestedArg value="baaz"/>
...
<nestedArg value="AAAAA"/>
</newFooTask>
Obviously, this isn't right. My question is, what's the right way to do this?
I need to pass a variable number of nested elements from one target to another.
For "varible", I assume you mean you don't know the exact number of the nested elements you want to pass to the task, so what you want is something like method(Object param...) in java, is it?
It's not a good idea to try such a way. Ant is not a scripting language but a build tool. It provides limited "scripting" possibilities.
However, you can try it in the following two ways:
1, If your nested element is just in the form of <elementName value="xx" />, you don't need anything complicated. Just pass another property containing a comma seperated list of the values, and process the list in your custom ant task. It's easy for Java to split the property into a list and process it.
2, If your nested element may be more complicated... maybe you can try reference:
Make a type fooTaskParams which can be referenced via an id:
<fooTaskParams id="_foo_task_params">
<nestedArg value="qux"/>
<nestedArg value="baaz"/>
...
<nestedArg value="AAAAA"/>
</fooTaskParams>
and pass the reference to the other build file:
<ant target="_newFooTaskWrapper" antfile="commonFile">
<property name="_arg1" value="hello"/>
<property name="_arg2" value="world"/>
<reference refid="_foo_task_params"/>
</ant>
and then make your task to be able to process the reference:
<newFooTask arg1="${_arg1}" arg2="${_arg2}" paramRefId="_foo_task_params" />
You may need to take care of reference override, or make your task able to process the ref as well as taking nested elements.
Read ant's manual about <ant> and <typedef> for more about this approach, and refer to SO Q&As like this when you encount any problem.
I'm currently looking to run static analysis over a pre-existing project. As the project is created and supplied by an off-site company, I cannot change the build process radically.
The project is split into a lot of sub-modules, located in various places. For other analyisi tools (JDepend, Google Testability Explorer, etc.), I have dynamically detected all build JAR files into a path element as follows:
<path id="built-libs">
<fileset dir="${overall-base}">
<include name="${some-common-base}/**/lib/*.jar" />
</fileset>
</path>
<property name="built-libs-string" refid="built-libs" />
For some tools, I use the build-libs, for others I use the string (in classpath form; x.jar;y.jar).
The trouble is, FindBugs uses a completely different format to any other;
<class location="x.jar"/>
<class location="y.jar"/>
...
Now, I could list all the JAR files manually, but then run the risk of this list going out of synch with the other tool's lists, or of introducing typos.
Another complication is that I also want to run the reports in Jenkins, in this case the extract directory for individual modules will depend on the job that has previously built the module (pipeline builds, modules extracted from SCM and built in parallel, the reporting occurring at the end of the pipline).
I could make a call out to the OS to run FindBugs, passing in the JARs in a space separated list (as in Invoking FindBugs from Ant: passing a space-separated list of files to java). However, I prefer a, Ant solution to an OS <exec... hack.
Note I know I have a similar problem for the sourcepath element, however, I'm assuming that solving the class element problem also solves the sourcepath one.
Ideally, FindBugs should be taking a resource collection rather than separate class elements. I'm not familiar with FindBugs, so I can't comment on why they have chose to go the class element route instead of a resource collection, however your comment about using exec implies that using a resource collection is a valid design alternative.
I would try rolling your own Ant macro, which invokes FindBugs directly using the java task. This should give you the control you need and avoiding the redundancy that the FindBugs Ant task would introduce.
Another option (which is an ugly hack) is to use the fileset to write a mini ant file with a FindBugs target, which you then invoke using the ant task. shudders
The Findbugs Ant task allows you to specify a filelist which can be used to specify multiple files. Quoting from the Findbugs documentation
"In addition to or instead of specifying a class element, the FindBugs
task can contain one or more fileset element(s) that specify files to
be analyzed. For example, you might use a fileset to specify that all
of the jar files in a directory should be analyzed."
Example that includes all jars at ${lib.dir}:
<findbugs home="${findbugs.home}" output="xml" outputFile="findbugs.xml" >
<auxClasspath path="${basedir}/lib/Regex.jar" />
<sourcePath path="${basedir}/src/java" />
<fileset dir="${lib.dir}">
<include name="*.jar"/>
</fileset>
</findbugs>
I use a specified property to create fileset:
<property name="cases" value="B.java,A.java,C.java" />
<fileset id="casesToBeRunning" dir="${src}" includes="${cases}" />
When casesToBeRunning created, I list the content of it:
<echo>Cases to be running: ${toString:casesToBeRunning}</echo>
it shows A.java,B.java,C.java which I'm not expected to.
I don't want Ant autosort for me, I need the original sort order of the property I defined to execute the cases orderly.
Anyone know how to handle this?
Ant filesets don't retain order - as you've seen. The related filelist type does respect ordering, so you might use:
<filelist id="casesToBeRunning" dir="${src}" files="${cases}" />
Whether the order is respected will depend on what task you plan to use to process the files. Most core Ant tasks that accept a fileset will accept a filelist instead, so you should be ok with them. For non-core tasks it may not work.
(Note that before Ant 1.8.0 some tasks didn't respect the order when traversing a filelist - among them copy for example).
In an Ant target I get a property, containing the list of directories to be included in further action (copying, filtering, etc.). It looks like this:
directories=dir1, dir2, dir3
I need a way to convert this list to a fileset or patternset that selects all the files in these directories.
I know I can use a script to generate pattern strings and then use it in the "include" or "exclude", but is there are a way to avoid scripts?
Note that as of Ant 1.9.4, there is a new construct <multirootfileset> that provides that functionality, even if the dirs are not siblings:
<multirootfileset basedirs="${directories}" includes="**/*">
How about using the antcontrib propertyregex task to convert the comma-separated list into wildcards suitable for a fileset?
<property name="directories" value="dir1, dir2, dir3" />
<property name="wildcard" value="${file.separator}**${file.separator}*" />
<propertyregex property="my_pattern"
input="${directories}"
regexp=", "
replace="${wildcard}," />
At this point we now have:
my_pattern=dir1/**/*,dir2/**/*,dir3
That can be used with a further suffixed wildcard to get the full fileset:
<fileset dir="." id="my_fileset" includes="${my_pattern}${wildcard}" />
(The fiddly ${wildcard} is to ensure portability between unix and windows filesystems, you could use /**/* if you're pure unix.)
Something like this should work:
<dirset includes="${directories}"/>
Yes, dirset isn't fileset. However, it may be enough, or else you can probably use a for or foreach from ant-contrib to iterate over the directories in your target. You might also be able to define a ResourceCollection based around the dirset. It might help to know what the "further action" is expected to be.
However, this feels like too much work ...
I'm currently working with some developers who like to set up Ant tasks that define environment specific variables rather than using properties files. It seems they prefer to do this because it's easier to type:
ant <environment task> dist
Than it is to type:
ant -propertyfile <environment property file> dist
So for example:
<project name="whatever" default="dist">
<target name="local">
<property name="webXml" value="WebContent/WEB-INF/web-local.xml"/>
</target>
<target name="remote">
<property name="webXml" value="WebContent/WEB-INF/web-remote.xml"/>
</target>
<target name="build">
<!-- build tasks here --->
</target>
<target name="dist" depends="build">
<war destfile="/dist/foo.war" webxml="${webXml}">
<!-- rest of war tasks here -->
</war>
</target>
I am finding it hard to convince them that properties files are they right way to go. I believe properties files are better because:
They provides more flexibility - if you need a new environment just add a new properties file
It's clearer what's going on - You have to know about this little "trick" to realize what they're accomplishing
Doesn't provide default values and the ability to use overrides - if they used property files they could provide defaults at the top of the project but have the ability to override them with a file
Script won't break if an environment task isn't supplied on command line
Of course all they hear is that they need to change their Ant script and have to type more on the command line.
Can you provide any additional arguments in favor of properties files over "property tasks"?
Properties tasks tightly couple the build file to environments. If your fellow developers are arguing that they "have to change their ant script" with your suggestions, why aren't they arguing about changing it every time they have to deploy to a new environment? :)
Perhaps you can convince them to allow both properties file and command-line configuration. I set up my Ant builds so that if a build.properties exists in the same directory as the build.xml, it reads it in. Otherwise it uses a set of default properties hard-coded into the build. This is very flexible.
<project name="example">
<property file="build.properties"/>
<property name="foo.property" value="foo"/>
<property name="bar.property" value="bar"/>
...
</project>
I don't provide a build.properties with the project (i.e. build.properties is not versioned in SCM). This way developers aren't forced to use the property file. I do provide a build.properties.example file that developers can reference.
Since Ant properties, once set, are immutable, the build file will use properties defined in this order:
Properties provided with -D or -propertyfile via the command line
Properties loaded from build.properties
Default properties within build.xml
Advantages of this approach:
The build file is smaller and therefore more maintainable, less bug-prone
Developers that just can't get away from setting properties at the command line can still use them.
Properties files can be used, but aren't required
The arguments you have are already pretty compelling. If those arguments haven't worked, then arguing isn't going to solve the problem. In fact, nothing is going to solve the problem. Don't assume that people are rational and will do the most practical thing. Their egos are involved.
Stop arguing. Even if you win, the resentment and irritation you create will not be worth it. Winning an argument can be worse than losing.
Make your case, then let it go. It's possible that after a while they will decide to switch to your way (because it actually is better). If that happens, they will act like it was their own idea. There will be no mention of your having proposed it.
On the other hand, they may never switch.
The only solution is to work towards a position of authority, where you can say how things are to be done.
The problem with the first solution (using ant property) is basically hardcoding.
It can be convenient when you start a project for yourself but quickly you have to remove that bad habit.
I'm using a property file close to what said robhruska except that I have committed the build.properties file directly. This way you have a default one.
In other hand, I understand I could add those default values in the build.xml. (I will probably try that in the next hours/days ;-) ).
Anyway, I really don't like the first approach and I would force those guys to follow the second one ...