Tag: build

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" />
    </copy>
    </target>
    </project>     
  • Make sure that you put the JAR (maven-ant-tasks-2.1.3.jar) in the proper place…

Executing:


  • 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.

REFERENCES:
http://maven.apache.org/ant-tasks/examples/dependencies.html
http://maven.apache.org/ant-tasks/
http://search.maven.org/#artifactdetails%7Corg.apache.maven%7Cmaven-ant-tasks%7C2.1.3%7Cjar

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

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

NOTE: This proves to be rather difficult to do because of the way that Maven copies resources as it’s building the WAR. The most reliable manner I’ve found (so far) is below, it works by making a .tmp copy of the web.xml in a different path and then later uses it in the WAR.


<plugins>
<plugin>
<groupId>com.google.code.maven-replacer-plugin</groupId>
<artifactId>replacer</artifactId>
<version>1.5.3</version>
<configuration>
<quiet>false</quiet>
</configuration>
<executions>
<execution>
<id>replaceBuildLabel</id>
<phase>prepare-package</phase>
<goals>
<goal>replace</goal>
</goals>
<configuration>
<file>${basedir}/src/main/webapp/WEB-INF/web.xml</file>
<outputFile>${project.build.directory}/web.xml.tmp</outputFile>
<replacements>
<replacement>
<token>BUILD_LABEL</token>
<value>Maven-${maven.build.timestamp}</value>
</replacement>
</replacements>
<regex>false</regex>
<quiet>false</quiet>
</configuration>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-war-plugin</artifactId>
<version>2.5</version>
<configuration>
<failOnMissingWebXml>false</failOnMissingWebXml>
<webXml>${project.build.directory}/web.xml.tmp</webXml>
<archive>
<manifest>
<addDefaultImplementationEntries>true</addDefaultImplementationEntries>
<addDefaultSpecificationEntries>true</addDefaultSpecificationEntries>
</manifest>
<manifestEntries>
<url>${project.url}</url>
<Build-Label>${maven.build.timestamp}</Build-Label>
</manifestEntries>
</archive>
</configuration>
</plugin>
</plugins>

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 [Maven-20141015-1700]</description>

REFERENCES:

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}/${ant.project.name}.war" webxml="${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>

REFERENCES:

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)

....
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-antrun-plugin</artifactId>
<version>1.7</version>
<executions>
<execution>
<phase>install</phase>
<configuration>
<target>
<echoproperties />
</target>
</configuration>
<goals>
<goal>run</goal>
</goals>
</execution>
</executions>
</plugin>

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

Ant: (build.xml)

...
<echoproperties />
...

REFERENCES:

Problems uploading/deploying large WAR’s to Tomcat7?

I’ve run into this a few times as my web applications got larger. Often this has been seen when builds automated by Jenkins start failing as they increase in size. It has also occurred to me when doing manual deployments as the Jenkins WAR itself is larger than 50MB lately.

Let’s just go in and increase the maximum expected file size…

This change should work on any platform, but the following is from my experience with Ubuntu.

sudo vi /opt/tomcat7/webapps/manager/WEB-INF/web.xml

Default is:

<multipart-config>
<!-- 50MB -->
<max-file-size>62428800</max-file-size>
<max-request-size>62428800</max-request-size>
<file-size-threshold>0</file-size-threshold>
</multipart-config>

Change to something a bit larger (to your liking):

<multipart-config>
<!-- 50MB max 62428800, 100MB = 104857600 -->
<max-file-size>104857600</max-file-size>
<max-request-size>104857600</max-request-size>
<file-size-threshold>0</file-size-threshold>
</multipart-config>

Restart with either…
sudo /etc/init.d/tomcat7 restart
or
sudo service tomcat7 restart

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"...>

REFERENCES:

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: http://ant.apache.org/
  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!