Map property in property file

Question

Hi all,
can we have a map property in properties file, i.e key value pair , and the value being a List or map or Array for example,
States.properties
state=\
AL=Alabama,\
MA=Massachusetts,\
CA=California,\
xyz=List or Map or array
can we have a list or map or array as value for XYZ????

Answer 1

Nucleus doesn't have any code that understands complex collection element structures. In other words, there's no automatic parsing of maps within maps or arrays within arrays. If you want that kind of structure, you have to write your own parsing code for the children. You have to be careful with your choice of delimiters so that something in a child isn't interpreted as a parent delimiter. The most complex example is a map of maps. You'd have a hard time if you tried to use = to separate the keys and values in the child maps and tried to use comma to separate child map elements.
Another option for the map of maps case is a ServiceMap, which is a map of Nucleus components. Instead of configuring child maps in the parent's properties file, you'd configure each child in its own properties file. If you go to the trouble of splitting out the child configurations into separate components, you might as well take the next step and create a pojo with named properties instead of stuffing all the child information into a map. Accessing pojo properties by name usually makes for more readable application code.