[Fix] Spring Tool Suite STS Code Autocomplete not working with Eclipse

I recently downloaded the latest version of the Spring Tool Suite (STS) on my Mac device and when I created the first Spring Web Services tool, I realized I was not able to make use of the autocomplete for Java code nor the Spring Annotations,

Go to Preferences.. -> Java -> Editor -> Content Assist -> Auto Activation and replace the below line in "Auto Activation trigger for Java",

abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ._

Click Apply and close!