Develop Reference

Ant can't find Maven's "DependenciesTask"

I'm at a loss at what's wrong. I have an Ant build.xml that has the line
<path id="maven-ant-tasks.classpath" path="lib/maven-ant-tasks-2.1.3.jar" />
and then later
<target name="clean">
<artifact:mvn pom="${basedir}/pom.xml">
<arg value="clean"/>
</artifact:mvn>
The error I get is
java.lang.NoSuchMethodError: org.apache.maven.artifact.ant.DependenciesTask.setPathType(Ljava/lang/String;)V
The .jar file exists in the Ant's lib/ folder, and it also contains said function (unzipped it and looked at .class file). Also, when I change the path in the "path=" attribute, it doesn't complain, which means it's not even looking!
Anyone have an idea why it's not even considering the "path=" element here? Strangely enough, for other people in my group it works, and it has for me too in the past (had to rebuild my machine and reinstall everything).

Apache Ant {Compile javac srcdir} does not exist

I am new to apache ant and I am currently working on an apache Ant project. I Just started out, imported the project into workspace and tried to run the build.xml. I added all the libraries that come with the original project to the build path. I am having the following problem. Please someone else wrote the code and I am supposed to improve it. The directories this is all about exist in the project directory.
BUILD FAILED
C:\workspace\MyApp\build.xml:83: srcdir "C:\workspace\MyApp\${compile.javac.srcdir}" does not exist!
The error code is referencing the following part of the build.xml file
<target name="compile.default" depends="init">
<javac fork="yes" srcdir="${compile.javac.srcdir}" destdir="${compile.javac.destdir}" includes="${compile.javac.include}" excludes="${compile.javac.exclude}" classpath="${compile.javac.classpath}" debug="${compile.javac.debug}" optimize="${compile.javac.optimize}" deprecation="${compile.javac.deprecation}" verbose="${compile.javac.verbose}">
</javac>
<copy todir="${compile.javac.destdir}">
<fileset dir="${compile.javac.srcdir}" includes="${compile.copy.include}" excludes="${compile.copy.exclude}"/>
</copy>
</target>
<target name="compile" depends="init,compile.default" description="Compile all java source">
</target>
<!--+++++++++++++++-->
<!-- lib target(s) -->
<!--+++++++++++++++-->
<target name="lib.default" depends="init,compile">
<xmlbean schema="config/schemas/validate/1.0/validate.xsd" destfile="lib/glx-beans.jar" classpath="lib/xbean.jar:lib/jsr173_1.0_api.jar" />
<jar jarfile="${lib.filename}">
<fileset dir="${lib.srcdir}" excludes="${lib.exclude}" />
</jar>
</target>
<target name="lib" depends="init,compile,lib.default" description="Create all Project Libraries">
</target>
Would you please tell me what I am missing?

The ${compile.javac.srcdir} isn't defined. There are a few possibilities:
This is defined not in the build.xml, but in some sort of properties file. See if you have something like <property file="..."/> in your build script. My recommendation is to have all properties defined in the build.xml file, and use a properties file to override those settings. This way, the only build file that a developer needs in the build.xml file and doesn't have to worry about setting up a separate build.porperties file.
This is defined in the build.xml file under a particular task, but you forgot to say that your target where you use thisis dependent upon this task.
One of the things you can do is use the -d parameter when running Ant. I run the following command when running Ant with the -d parameter:
$ and -d 2>&1 | tee ant.out
I can then look at ant.out and see if somehow I didn't define that particular property. Maybe I had the wrong capitalization or misspelled the property name. For example, it's very likely I'll define the property as copmile.javac.srcdir because I don't know how to spell. Looking at the -d output can quickly point these types of errors out.
By the way, you shouldn't have all of your tasks dependent upon init since they're dependent upon compile.default anyway:
<target name="compile.default" depends="init">
....
</target>
<target name="compile" depends="compile.default">
....
</target>
<target name="lib" depends="compile,lib.default">
....
</target>
If I run the target lib, it will see compile is dependent upon compile.default which is dependent upon init. Thus, your build will run init, then compile.default, then compile, then 'lib.defaultand finallylib`.
If the init task is just setting up properties, you can do that outside of any task. Then, these properties will be setup before any task is executed. This way, they're not forgotten. If your init is also creating directories, you may want to move those <mkdir/> tasks in front of the task where that directory is used. For example, you may want to make the destdir uses in javac before the <javac/> task.
I find assigning default properties outside of any task, and creating directories before they are needed to simplify the build.xml. Plus, you're not creating a whole flock of unused directories if the user is merely compiling and not packaging the jar/war/etc.

copy a file in ant based on condition

I have to copy a file if a property is set in ant target, but I always get an error for this code:
<condition property="component.is.x">
<equals arg1="${COMPONENT_ID}" arg2="x" />
</condition>
<target name="copyschemaparamsfile" if="sql.file.present" >
<if>
<equals arg1="${component.is.x}" arg2="true" />
<then>
<copy file="${in.root}/schema/${COMPONENT_ID}-schema.sql"
tofile="${tmp.dir}/${COMPONENT_ID}/x/schema/schema.sql"
failonerror="false" />
</then>
<else>
<copy file="${inf.root}/schema/${COMPONENT_ID}-schema.sql"
tofile="${tmp.dir}/${COMPONENT_ID}/${COMPONENT_ID}/schema/schema.sql" failonerror="false" />
</else>
</if>
</target>
Error is:
Ant could not find the task or a class this task relies upon.
This is common and has a number of causes; the usual
solutions are to read the manual pages then download and
install needed JAR files, or fix the build file:
- You have misspelt 'if'.
Fix: check your spelling.
- The task needs an external JAR file to execute
and this is not found at the right place in the classpath.
Fix: check the documentation for dependencies.
Fix: declare the task.
- The task is an Ant optional task and the JAR file and/or libraries
implementing the functionality were not found at the time you
yourself built your installation of Ant from the Ant sources.
Fix: Look in the ANT_HOME/lib for the 'ant-' JAR corresponding to the
task and make sure it contains more than merely a META-INF/MANIFEST.MF.
If all it contains is the manifest, then rebuild Ant with the needed
libraries present in ${ant.home}/lib/optional/ , or alternatively,
download a pre-built release version from apache.org
- The build file was written for a later version of Ant
Fix: upgrade to at least the latest release version of Ant
- The task is not an Ant core or optional task
and needs to be declared using <taskdef>.
- You are attempting to use a task defined using
<presetdef> or <macrodef> but have spelt wrong or not
defined it at the point of use
Remember that for JAR files to be visible to Ant tasks implemented
in ANT_HOME/lib, the files must be in the same directory or on the
classpath
I am always getting above error when I execute. Can someone please suggest how to check for a parameter and copy from one directory to other within an ant target?

Ant <if/> is part of Ant-Contrib. To use, follow the directions on the Ant-Contrib Tasks installation page:
(1) Copy ant-contrib-0.3.jar to the lib directory of your Ant
installation. If you want to use one of the tasks in your own project,
add the lines
<taskdef resource="net/sf/antcontrib/antcontrib.properties"/>
to your build file.
(2) Keep ant-contrib-0.3.jar in a separate location. You now have to
tell Ant explicitly where to find it (say in /usr/share/java/lib):
<taskdef resource="net/sf/antcontrib/antcontrib.properties">
<classpath>
<pathelement location="/usr/share/java/lib/ant-contrib-0.3.jar"/>
</classpath>
</taskdef>

Error: Could not find or load main class using XML

I am trying to implement my build.xml file so I can compile and create a Jar using ANT. In order to run some JUnit tests I need to first manually start up a custom Server on port 7777. However, I am having trouble starting the server up using XML. This is my code so far:
<property name="server" location="cs.hw4.Server"/>
<target name="run">
<java fork="true" failonerror="yes" classname="${server}">
<classpath refid="cs.hw4.classpath"/>
<arg line="7777"/>
</java>
</target>
I run the build.xml and I get the: Error: Could not find or load main class F:...
I am finding that the error is trying to find class in the directory:
...\cs.hw4\cs.hw4.Server
When it is actually in:
...\cs.hw4\ bin \cs.hw4.Server
The funny thing is that the classpath refid= "cs.hw4.classpath" includes the "bin" folder.
Any ideas?

You can try this way. Right click on the ant build file and run as you should see a window that pops out with the Classpath and Jar file path. Remove that and add it manually. This time you should see no conflicts.

What is the difference between the <pathelement> attributes 'path' and 'location' in Ant?

I was running Selenium unit tests in TestNG with the Ant Java task like so:
<java classpathref="runtime.classpath"
classname="org.testng.TestNG"
failonerror="false">
<arg value="-d" />
<arg value="${grid.location}/target/reports" />
<arg value="${lib.location}/testng.xml"/>
</java>
runtime.classpath is a pathlike structure that included <pathelement path="${basedir}/target/classes/" />, which I thought was needed to let TestNG know which classes to run.
<path id="runtime.classpath">
...
<!-- Target classes -->
<pathelement path="${basedir}/target/classes/" />
</path>
However, I kept seeing in the log that TestNG found 0 applicable classes.
I eventually got some help from a colleague and it appears this was the key change:
<path id="runtime.classpath">
...
<!-- path attribute changed to location -->
<pathelement location="${basedir}/target/classes/" />
</path>
This also pulls in the test classes correctly:
<java classpathref="runtime.classpath"
classname="org.testng.TestNG"
failonerror="false">
<arg value="-d" />
<arg value="${grid.location}/target/reports" />
<arg value="${lib.location}/testng.xml"/>
<classpath>
<pathelement location="${basedir}/target/classes/" />
</classpath>
</java>
What is the difference between the path and location attributes? I've looked at Writing a Simple Buildfile (specifically the Path-like Structures section), but in that manual it looks to me like location is more specific than path. That doesn't appear to be the case empirically, but I can't quite figure out why.

It looks like the difference between path and location is many entries vs one. A location is a file or directory, a path can be a list.
From the manual
The location attribute specifies a single file or directory relative
to the project's base directory (or an absolute filename), while the
path attribute accepts colon- or semicolon-separated lists of
locations. The path attribute is intended to be used with predefined
paths - in any other case, multiple elements with location attributes
should be preferred.
Note that the JVM used by ant has just about no relation to the JVM used by the java task. By default the environment of ant isn't the same as that of things started with the java task via ant. This is actually helpful when you want to use a different JVM from the one ant wants to use and makes things explicit, helping avoid surprises later on.
Check out the docs for the java task, particularly clonevm
clonevm: If set to true, then all system properties and the
bootclasspath of the forked Java Virtual Machine will be the same as
those of the Java VM running Ant. Default is "false" (ignored if fork
is disabled). since Ant 1.7