First you need to create package:
com.myCompany.executabe (src > right click > new > package).
Follow these steps to move the Java files to your new package.
Select the Java files
Right click
Refactor
Move
Select your preferred package
You can’t rename default package since it actually doesn’t even exist. All files in default package are actually in src folder.
src–
|
MyClass1.java <==== These files are in default package
MyClass2.java
|
org
|
mypackage
|
MyClass3.java <=== class in org.mypackage package
Just create new package and move your classes within.