add main

    package main;

    import java.util.Arrays;
    import java.util.List;
    import java.util.ArrayList;

    class ParseArray {
        public static void main( String [] args ){
            String input = "[    [ 1] , [2,3],[4, 5,6 , 7],[8,9,10    ,  11,      12,    13]        ]";

            List<String[]> multiDimArray = new ArrayList<String[]>();

            String [] parts = input
                .replaceAll("\\s*\\[\\s*","[") // clean starting spaces
                .replaceAll("\\s*,\\s*", ",")  // middle spaces
                .replaceAll("\\s*\\]\\s*","]") // ending spaces
                .replaceAll("\\[\\[|\\]\\]","") // and remove leading an trailing [['s and ]]'s

                .split("\\],\\[");  // finally split by ],[

            for( String s : parts ){
                multiDimArray.add(  s.split(",") ) ;
            }

            String [][] result = multiDimArray.toArray( new String[multiDimArray.size()][]);
            print( result );
        }
        public static void print( String[][] array ){
            System.out.println( Arrays.deepToString( array ));
        }
    }