Requirements

1. You need ROOT installed on your computer, and root-config location should be in your PATH environment variable. You can check it by running root-config in your command line
2. The JDK introduces a bridge between the bytecode running in our JVM and the native code. So you need JNI header files accessible in the system default header locations or specify JAVA_HOME environment variable. You should be able to find jni.h and jni_md.h in your $JAVA_HOME/include location.
3. Clone the repo, run scons, install coatjava, run maven:

git clone https://github.com/mfmceneaney/j2root.git
cd j2root
javac -h build/native src/main/java/org/jlab/jroot/JRootJNI.java
sed -i.bak 's;^env.JavaH;#env.JavaH;g' sconscript
scons
./install_coatjava.sh
mvn package
sed -i.bak 's;^set sourced;set sourced=\(\"source\" \"j2root/setup.csh\"\)#set sourced ; g' setup.csh

4. Set environment variables:

• source setup.sh in bash
• source setup.csh in csh

5. run-groovy root.groovy

Wiki

https://github.com/drewkenjo/j2root/wiki

Troubleshooting

array length is not legal

If your tree contains more than 250 branches your code can fail with this error

Caught: java.lang.IllegalArgumentException: array length is not legal:
java.lang.IllegalArgumentException: array length is not legal:

The reason is because the length of the varargs is limited, and groovy fails when you pass too many arguments in fill method. The solution is to use List in the fill method instead of varargs.

Instead of:

tree.Fill(0,1,2,3,4,5,6)

use:

tree.Fill([0,1,2,3,4,5,6])