Code signing of java applets – using Ant

To sign your java assets during the Ant build process, you can add the following to the build.xml to make use of the values we established in the keystore creation step.

Something as simple as the following could be used:

<signjar jar="example.jar" alias="selfsigned" keystore="" keypass="123456" storepass="123456"/>

I generally prefer to add the following:

In – I externalize the variables…


Then, in build.xml – a ‘task’ for signing…

<property file=""></property>
... snip ...
<target name="signwar" depends="war">
<echo message="--- signing ---" />
<signjar jar="${build.dir}/${}.war" alias="${signing.alias}" keystore="${signing.keystore}" keypass="${signing.keypass}" storepass="${signing.storepass}" />


Code signing of java assets – creating a keystore

This is generally done via the command line, though I’ve seen it done with Ant in some cases. Here are the specifics… you’ll want to change the passwords and likely take a look at the algorithm (RSA for this example and validity (365 days in this example) for your actual use.

Background, in order to sign your java assets, you will first need to generate a key. You can later get this verified by a CA (Certifying Authority) as needed, this example is selfsigned.

NOTE: I’ll use these example values in the Maven and Ant signing code examples to follow.

keytool -genkey -keyalg RSA -alias selfsigned -keystore -storepass 123456 -keypass 123456 -validity 365


Using Ant to parse and download Maven pom.xml dependencies

I’ve migrated most of my projects to Maven, but occasionally have some developers that prefer to use Ant in their development environments. One problem that I used to have with Ant was that it required all dependencies to be checked into the SCM repository for each project. I recently found an Ant plugin that allows for it to read the Maven pom.xml and download the required dependencies, thus making projects MUCH easier to maintain! the steps are very simple.

Maven – pom.xml

  • Make sure that you have your dependencies (nexus?) setup and tested here.

Maven – global settings.xml

  • Make sure that your repositories are correctly configured.

Ant – build.xml (very minimal, I usually add as a step in existing scripts vs. using as standalone)

  • (example):

    <?xml version="1.0" encoding="UTF-8" standalone="no"?>
    <!DOCTYPE project>
    <project name="example" basedir="." default="dependencies" xmlns:artifact="antlib:org.apache.maven.artifact.ant">
    <taskdef uri="antlib:org.apache.maven.artifact.ant" classpath="ant/maven-ant-tasks-2.1.3.jar" />
    <target name="dependencies">
    <echo message="--- getting dependencies from maven pom.xml ---" />
    <artifact:pom id="pom" file="pom.xml" /><!-- settingsFile="settings.xml" -->
    <artifact:dependencies filesetId="test.dependencies" pomRefId="pom" useScope="test" />
    <copy todir="${antlib.dir}">
    <fileset refid="test.dependencies" />
    <mapper type="flatten" />
  • Make sure that you put the JAR (maven-ant-tasks-2.1.3.jar) in the proper place…


  • ant dependencies

If everything is working well, you can now purge most of the JAR’s that reside inside your web projects as the Ant build process can retrieve them based on values in the Maven pom.xml file.


Ant build script for replacement of text in web.xml (and others)

Automated replacement of BUILD_LABEL in web.xml <description> with Ant. For JAR’s the replacement is commented out, but can be any file

<replace file="${webapp.dir}/WEB-INF/web.xml" token="BUILD_LABEL" value="Ant-${DSTAMP}-${TSTAMP}" />
<war destfile="${jar.dir}/${}.war" webxml="${webapp.dir}/WEB-INF/web.xml" compress="true">

Most importantly, you will want to have this token in the web.xml file for replacement, the description line is best used for this as such:

<description>ExampleWAR [BUILD_LABEL]</description>

during the build, that value would be replaced to something like:

<description>ExampleWAR [Ant-20141015-1700]</description>


Maven/Ant echoproperties at build time

Once you have started using automation tools for continuous builds, you often find edge cases where your builds have minor variations due to the environments on which the projects have been built. To isolate these, it is often useful to have the build tool output a snapshot of it’s properties at the time the project was built. Thankfully, Ant and Maven make this easy to implement, required additions to your config files are below for each tool.

Maven: (pom.xml)

<echoproperties />

NOTE: ‘target’ is preferred over ‘tasks’ in newer versions of the plugin, it was deprecated in 1.5.

Ant: (build.xml)

<echoproperties />


DTD for Ant build.xml in Eclipse

I’ve seen this validation error in Eclipse for a few releases and finally got tired enough of seeing it that I did some research.

The simplest method to silence the warning is to add a DOCTYPE to the build.xml files, between the XML declaration and the project, there are a few more complicated methods, but this one works well for the cases I’ve experienced.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE project>
<project name="Example"...>


Apache Ant for Windows

Apache Ant is frequently used as a build tool in many environments, here’s the simple installation for Windows. As I haven’t had to install this in a very long time, but find myself doing it again, I’ve captured it here for reference.

  1. Download ZIP from:
  2. Uncompress it, generally I place tools like this at the root of my hard drive.
  3. Open the System Control Panel
  4. Add Environmental variable, ANT_HOME = “c:\apache-ant-x.xx”
  5. Update Environmental variable for PATH, adding %ANT_HOME%\bin
  6. Save changes in Control Panel.
  7. Open a new command window (DOS prompt).
  8. Enter: ant -version
  9. If your installation is correct, you should see output containing the version you’ve just installed.

Happy Builds!