OpenJDK 7 is an open source implementation of version 7 of the Java
Development Kit, Standard Edition. It includes tools for developing,
testing, and running programs written in Java.

apache-ant is a required dependency and you have to install it before
you build 'openjdk7'. However, you do not need to install Oracle's jdk,
since it's only a runtime dependency of apache-ant.

Before installing this package please consider any other jdk's/jre's
that you have already installed as they may cause conflicts with the
PATH, JAVA_HOME and MANPATH variables.

After installing the package you will need to logout/reboot your
machine as it will add new files to the /etc/profile.d folder.

This script may take a couple of hours to complete and will require
about 11 GB of disk space for its temporary directory. It defaults to
"/tmp/SBo" and you may redefine it like this:

TMP=/your/temporary/dir ./openjdk7.SlackBuild

The 'cacerts' binary is a TrustStore containing CA certificates which
are used by Java applications. It is taken from the CentOS package
'ca-certificates-2015.2.4-65.0.1.el6_6.noarch.rpm'.

If you get an error like

Internal compiler error: java.lang.NullPointerException at
org.eclipse.jdt.internal.compiler.ReadManager.run(ReadManager.java:166)

simply run the build again. This happens early so it shouldn't be that
of a problem. At least 1 out of 5 runs so far have always succeded.