Java config file multidimensional array

I have a problem. For my code I have a config file with the following content:

updateOnInsert=true
removeLast=false

names=Joey Greek, Lisa Blessing, Arnold Verdict

To read this config file, I have the following code:

ClassLoader classloader = Thread.currentThread().getContextClassLoader();
InputStream is = classloader.getResourceAsStream("configs/main.config");
                
// Read all properties from agent strategy file
Properties properties = new Properties();
properties.load(is);

// Assign all properties to variables
boolean updateOnInsert = Boolean.parseBoolean(properties.getProperty("updateOnInsert"));
boolean removeLast = Boolean.parseBoolean(properties.getProperty("removeLast"));

List<String> names = Arrays.asList(properties.getProperty("names").split(", ", -1));

But now I need to change the format of the names to:

names=[[Joey, Greek], [Lisa, Blessing], [Arnold, Verdict]]

The output varialbe has to be of the type: String[][] with as result:

[0] => [Joey, Greek]
[1] => [Lisa, Blessing]
[2] => [Arnold, Verdict]

What is the best way to achieve this?

Answer

Depends on what the input could look like. The safest way would probably be to use a proper parser (and maybe a different file format).

If the list is always in the form [[Name], [Name]] and Name never contains brackets, a simple way could be to use a more specialized regex, e.g. (?<=]),s*(?=[).

Rundown on the regex:

• (?<=]): a positive look-behind, i.e. any match must follow a ].
• ,s*: the actual match to split at (and remove), i.e. a comma followed by any whitespace
• (?=[)"): a positive look-ahead, i.e. any match must be followed by a [.

Finally, split each of the names by , to get the 2D array:

//results in Strings like "[Joey, Greek]", "[Lisa, Blessing]", and "[Arnold, Verdict]"
String[] completeNames = properties.getProperty("names").split("(?<=\]),\s*(?=\[)");

//We're using a stream here but you could as well use traditional loops   
String[][] namesInParts = Arrays.stream(completeNames)
           //map the name by removing the brackets and splitting at the comma (followed by any whitespace)
           .map(name -> name.replaceAll("[\]\[]", "").split(",\s*"))
           //collect everything into a new array
           .toArray(String[][]::new);