Normally all the classes we need to run a java program are packaged in the jar files.
These jars are added to the classpath by the JVM which loaded them as required. What if we want these jars to be added at runtime instead of startup?
 
This snippet shows how the load class at Runtime by adding the jar path into using

This snippets demonstrates how to execute shell command (navtive to OS) and captures its output as if it was running from the command line. Once the command is executed, it waits for it, and captures any output produced by the command and dumps it to the screen.
 
Remember this piece of code has to be executed from a Unix/Linux shell, or cygwin or dos shell in order for this to work.

 Loading  properties is easy as long as you know the path to the properties file. This can be issue 

at times when you either don't know the exact location of the file or it can change based on

 environment. In this case loading such file using the classpath loader turns out to handy.  

Its easy to print the stack trace using e.printStackTrace() where e is instance of an Exception/Throwable.  This prints the trace to the Standard Error stream. But how about if you want to have the stacktrace stored in file or database or want to search as text. This snippets shows how to get the stack trace as String.

The following snippet checks if a given directory exists or not. If it does not it, then creates it. It also creates any non existent directories in the path. The magic is performed by the java.io.File mkdirs() method.