Installing HPS Java

Quick Build Instructions

Assuming you have internet access and the right command line tools installed already, this should do it.

cd /my/work/dir
svn checkout svn://svn.freehep.org/hps/java/trunk hps-java-trunk
cd hps-java-trunk
mvn install -DskipTests
java -jar distribution/target/hps-distribution-[VERSION]-bin.jar

The last command will check that the distribution was installed correctly.

That's it!  If you need help installing the build tools, then continue reading the next section.

Preliminary Tools

Before beginning the installation process, you will want to have available the following tools on your machine first.

Unix

Being Java software, the project is cross-platform and should run on Linux, OSX and Windows. 

The setup instructions assume a Unix-like environment using the bash shell.  Windows users should be able to execute the equivalent commands on their system to perform the installation successfully.

Java

The software is currently compatible with Java versions 1.7 and greater.  It will not currently build with Java 1.6 or other earlier versions.  You need to download the "Java Platform (JDK)" and not just the JRE.  It should work with Java 1.8 releases.

The bundle for your system should be downloaded from the Java SE downloads site.  Then you need to follow the setup instructions listed there.

You may want to add lines like the following to your shell initialization script, especially if Java is not installed in a standard system location like the /usr directory.

export JAVA_HOME=/path/to/java/jdk
export PATH=$JAVA_HOME/bin:$PATH

This will make sure that the shell can find the Java commands such as java and javac that will be needed for the installation.

There have been problems when using the OpenJDK distribution of java to compile HPS Java.  Therefore, make sure that the distribution of java is Oracle's version.

Once the Java installation is completed, you should make sure that the compiler is available from the command line.

[$] javac -version
javac 1.7.0_17

If this command prints "command not found", the current PATH variable probably does not contain the Java bin directory or the location was set incorrectly.

Maven

Maven is a Java based build tool used to create a runnable version of HPS Java on your machine.

You will need to get Maven from the Maven Download Site and save (for instance) the tar.gz file to your machine.

Then you can set it up as follows.

tar -zxvf apache-maven-3.2.3-bin.tar.gz
export MAVEN_HOME=$PWD/apache-maven-3.2.3
export PATH=$MAVEN_HOME/bin:$PATH

Now you should check that the mvn command works.

[$] mvn -version
Apache Maven 3.2.3 [etc.]

If this command does not work, then you should check that the PATH variable is set correctly.

Subversion

Subversion is the source control system system used to obtain the source code from a remote server.  You will need the Subversion client tool in order to checkout the HPS Java code.

Subversion should not be compiled from source code.  It is probably best to either have your local administrator install it if it is not present already, or you can use your package manager (like yum on Redhat systems).

This is an example of using your package manage to do this.

yum install subversion

Windows users can install the TortoiseSVN tool, but its usage is not covered in these instructions.

Build Instructions

Obtaining the Source Code

First, you are going to want to create some kind of work directory.

mkdir /work/hps
cd /work/hps

You will now use the svn command to checkout the trunk, or main development branch, of the HPS Java Project.

svn checkout svn://svn.freehep.org/hps/java/trunk hps-java-trunk

This may take awhile as the source code is downloaded from the server.

Now you can cd into hps-java-trunk to execute build commands.

Building the Maven Project

From the hps-java-trunk directory, you can execute the following command to build the project.

mvn -DskipTests

Especially the first time this is done, it may take quite a long time to bootstrap Maven and download all jar dependencies.

The directory containing the Maven jar cache (or repository) is by default in ~/.m2/repo but can be changed using a command line option.

mvn -Dmaven.repo.local=/path/to/my/repo

At JLab, you might want to use a directory on the work disk for the repo so your home directory does not get filled up.

Building a Maven Module

The list of available modules is available from the Project Modules Webpage on the HPS Java site generated by Maven.

To build a single module, assuming you already have a local copy of the SVN trunk, you just need to go to its sub-directory and type the appropriate Maven command.

For instance, this command will build the tracking reconstruction module.

cd hps-java-trunk/tracking
mvn -DskipTests

This will install that module's jar into your local Maven repository.  In order to include these changes in the distribution jar, you also need to build the distribution module, also.

cd hps-java-trunk/distribution
mvn

Running the Distribution Jar

The primary tool produced by the installation is a standalone, runnable jar file that can be used along with XML steering files to run reconstruction jobs.

In order to test the installation, you may execute a command such as the following where VERSION is replaced by your actual version from the last successful build.

java -jar ./distribution/target/hps-distribution-[VERSION]-bin.jar

The Maven tool will also install this file into your local repository.  This is an example of running the bin jar from your local repository.

java -jar ~/.m2/repository/org/hps/hps-distribution/3.0.3-SNAPSHOT/hps-distribution-3.0.3-SNAPSHOT-bin.jar

The output of these commands will be something like this.

java -jar lcsim-bin.jar [options] steeringFile.xml
usage:
 -D    Define a variable with form [name]=[value]
 -b    Run in headless mode in which plots will not be shown.
 -i    Add an LCIO input file to process
 -n    Set the max number of events to process
 -p    Load a properties file containing variable definitions
 -q    Turn on quiet mode
 -r    Use a steering resource rather than a file
 -s    Set the number of events to skip
 -v    Turn on verbose mode
 -w    Rewrite the XML file with variables resolved
 -x    Perform a dry run which does not process events

Actually running steering files using this tool is covered elsewhere.

Congratulations!  You now have a working local installation of HPS Java.

Using Distributions Jars from Nexus

As an alternative to the above instructions for building the software locally, you may also download and run the distribution jars from a Nexus repository.

This search URL will show all the available versions of the distribution jar that can be downloaded.

You can also get the latest version from Nexus at http://srs.slac.stanford.edu/nexus/index.html#nexus-search;quick~hps-distribution

Now you can simply click on the "bin jar" link for the distribution version you want to download, save it to your machine, and run it using the previous instructions.

Subversion Credentials

HPS Java is publicly accessible as a read only download from the server.  But valid credentials must be supplied in order to commit your local source code changes to the repository.

To commit changes, the username and password must be supplied, or the command will fail:

svn commit --username [username] --password [password] -m "commit message goes here" the/file/to/commit

After the username and password have been supplied once, they can be cached automatically in the directory ~/.subversion if you select 'Y' when prompted whether to store them (unencrypted unfortunately!).  Then these two arguments can be omitted from subsequent commit commands.

Resolving Maven Dependencies

Maven is able to resolve project dependencies by downloading jar files from remote repositories.  In order to do this, it must know about the locations of these jars, or local builds can fail with errors about missing dependencies.

This should not be a problem when building the entire trunk  But errors may occur when building individual modules, if the parent POM has not already been installed locally beforehand.

There are several different ways to resolve these kinds of issues, and generally only one will be needed:

1. Install the entire set of modules locally by building the trunk.
2. Checkout and build the parent module at svn://svn.freehep.org/hps/java/trunk/parent which contains the remote repository locations.
3. Add the remote repository to your global Maven settings file.

The third option entails adding the remote repository information to a local settings file that will apply to all your local Maven builds.

In order to do this, the following XML can be put into the file ~/.m2/settings.xml which you should create if it does not exist already:

<?xml version="1.0"?>
<settings>
    <profiles>
        <profile>
            <id>yourNameHere</id>
            <activation>
                <activeByDefault>true</activeByDefault>
            </activation>
            <repositories>
                <repository>
                    <id>lcsim-maven</id>
                    <name>org.lcsim Maven Repository</name>
                    <url>http://srs.slac.stanford.edu/nexus/content/groups/lcsim-maven2-public/</url>
                </repository>
            </repositories>
        </profile>
    </profiles>
</settings>

The above configuration will allow Maven to check the repository used by HPS whenever it looks for dependencies during a build.