Convert HashMap.toString() back to HashMap in Java

Question

I put a key-value pair in a Java HashMap and converted it to a String using the toString() method.

Is it possible to convert t

Answer 1

It will work if toString() contains all data needed to restore the object. For example it will work for map of strings (where string is used as key and value):

// create map
Map map = new HashMap();
// populate the map

// create string representation
String str = map.toString();

// use properties to restore the map
Properties props = new Properties();
props.load(new StringReader(str.substring(1, str.length() - 1).replace(", ", "\n")));       
Map map2 = new HashMap();
for (Map.Entry e : props.entrySet()) {
    map2.put((String)e.getKey(), (String)e.getValue());
}

This works although I really do not understand why do you need this.