Lazily initialize a Java map in a thread safe manner

Question

I need to lazily initialize a map and its contents. I have the below code till now:

class SomeClass {
    private Map someMap = null;

         


        

Answer 1

I think TimB explained most of the options very well, but I think the quickest and most obvious answer would be to create it when the class instance is instantiated.

class SomeClass {
    private final Map someMap = new HashMap();

    public String getValue(String key) {
        return someMap.get(key);  // the key might not exist even after initialization
    }
}