How to delete all rows of a table and also reset the index.

How to insert images when outputting excel using POI packages in Java.

Java common data type and structure operations.

Code example to show that when a new instance is created, Java only creates instance for the sub class, and for the super class.

Java open url with URL and URLConnection.

Code example to show that Java child class also inherits parent class private fields.

How to group a list of objects by one of the object’s attribute, which is similar to SQL group by statement and having the same results.

Java base64 encode and decode example.

Java String concatenation performance concern.

ThreadPoolExeuctor from concurrent.futures package in Python 3 is very useful for executing a task (function) with a set of data (parameter) concurrently and this post lists examples on how to pass MULTIPLE parameters to the task being executed.