title: Sorting a HashMap by date
body: <p>In a Java class I have a method to reOrder an existing HashMap by date. The HashMap is of a type <code>&lt;String, Object&gt;</code> where the Object contains a field called expPayDate and the key string is a sequential number turned into a string.. So I need to loop through the items in the sourceMap and find the item with the newest date then copy it to a tempMap in the correct order. My issue is what is the best way to determine the item with the newest date.</p>