Customize ant class loader

Old Forum
1

I’m writing a custom plugin to call a legacy ant task.

This ant task needs some jars i ant classpath.

In groovy, I could do something like

project.antBuilder.withClasspath(.....)
or
myclasspath.each{ jarpath ->
    antClassLoader.addURL(file("${jarpath}").toURI().toURL())
}

Bu my plugin is written in java. What’s the corresponding way to add things to the underlying ant project ?

2

Your first example is trying to use the internal ‘IsolatedAntBuilder’. The second (as far as I understand it) is modifying global classloaders, which is always a bad idea.

I’d recommend using the public AntBuilder, and using the http://groovy.codehaus.org/api/groovy/util/AntBuilder.html API to use ‘typedef’ (and friends) constructs, directly via the Ant project object (i.e. using Ant’s Java API).

3

Hi Luke

you’re right, my second example was missing the antClassLoader declaration, which was

def antClassLoader = org.apache.tools.ant.Project.class.classLoader

But anyway, based on your intel, I coded :

String jarToInclude = "full/path/to/ant/contrib.jar"
Typedef typeDef = new Typedef();
typeDef.setProject(getProject().getAnt().getAntProject());
typeDef.setURI(new File(jarToInclude).toURI().toString());
typeDef.setOnError(new Typedef.OnError(Typedef.OnError.POLICY_FAILALL));
typeDef.execute();

But the build still fails. My (legacy) ant script (that I cannot modify) does

<condition property="IfTaskAvailable">
    <available classname="net.sf.antcontrib.logic.IfTask"/>
 </condition>
<fail message="The If task is not defined" unless="IfTaskAvailable"/>
4

Looks like you need to use ‘taskdef’.

http://ant-contrib.sourceforge.net/

5

BTW, there’s some interesting info on this thread: http://forums.gradle.org/gradle/topics/need_help_trying_to_invoke_an_external_ant_script

6

In java, I tried various combinations close to the following code

Taskdef taskDef = new Taskdef();
taskDef .setProject(getProject().getAnt().getAntProject());
taskDef .setURI("antlib:net.sf.antcontrib");
taskDef .setClasspath(new Path(getProject().getAnt().getAntProject(), ajcrcAntConfPath));
taskDef .execute();

but every time, the class cannot be found when executing the legacy ant file. I do not know how to populate the taskdef object (and did not find any good example over the net)

7 
ant.taskdef resource: "net/sf/antcontrib/antcontrib.properties",
                 classpath: configurations.antcp.asPath

is the way to do it in the build.gradle script or in the groovy file of the plugin.

But what’s the java way ? I also tried

Taskdef taskDef = new Taskdef();
        taskDef .setResource("net/sf/antcontrib/antcontrib.properties");
        taskDef .setProject(getProject().getAnt().getAntProject());
        taskDef .setClasspath(new Path(getProject().getAnt().getAntProject(), "full/path/to/ant-contrib.jar"));
        taskDef .execute();

but this does not work either

8

to be more accurate, it seems to work

15:19:54 15:19:54.880 [DEBUG] [org.gradle.api.internal.project.ant.AntLoggingAdapter] Finding class net.sf.antcontrib.logic.IfTask$ElseIf
15:19:54 15:19:54.881 [DEBUG] [org.gradle.api.internal.project.ant.AntLoggingAdapter] Loaded from /xxxxx/ant-contrib.jar net/sf/antcontrib/logic/IfTask$ElseIf.class
15:19:54 15:19:54.882 [DEBUG] [org.gradle.api.internal.project.ant.AntLoggingAdapter] Class net.sf.antcontrib.logic.IfTask$ElseIf loaded from ant loader (parentFirst)

but then when importing the legacy build, it fails.

My plugin does

Taskdef taskDef = new Taskdef();
        taskDef .setResource("net/sf/antcontrib/antcontrib.properties");
        taskDef .setProject(getProject().getAnt().getAntProject());
        taskDef .setClasspath(new Path(getProject().getAnt().getAntProject(), "full/path/to/ant-contrib.jar"));
        taskDef .execute();
...
        getProject().getAnt().importBuild("legacyBuildFile");
        getProject().getAnt().getAntProject().executeTarget("legacy ant target");

but the gradle output is

15:19:57 15:19:56.484 [INFO] [org.gradle.api.internal.project.ant.AntLoggingAdapter] [ant:echo] checking that the Ant If and For tasks are available for Ant
15:19:57 15:19:56.496 [DEBUG] [org.gradle.api.internal.project.ant.AntLoggingAdapter] [ant:available] class "net.sf.antcontrib.logic.IfTask" was not found
15:19:57 15:19:56.496 [DEBUG] [org.gradle.api.internal.project.ant.AntLoggingAdapter] [ant:available] Unable to load class net.sf.antcontrib.logic.IfTask