How to instantiate a Singleton multiple times?

Question

I need a singleton in my code. I implemented it in Java and it works well. The reason I did it, is to ensure that in a mulitple environment, there is only one instance of th

Answer 1

You may keep a key on a map and populate instance with key

public class MultiSingleton {
/**** Non-static Global Variables ***/
String status = "";
private BaseSmartCard bsc;
/***********************************/
private static Object lockObject = new Object();
private String serialNo;

private static Map mappedObjects = new TreeMap();

protected MultiSingleton() {

}


public static MultiSingleton getInstance(String serialNo,long slotNo){
    if (mappedObjects.isEmpty() || !mappedObjects.containsKey(serialNo)) {
        MultiSingleton instance = new MultiSingleton();
        instance.setSerialNo(serialNo);
        mappedObjects.put(serialNo, instance);
        return instance;
    } else if (mappedObjects.containsKey(serialNo)) {
        return mappedObjects.get(serialNo);
    }else {
        return null;
    }
}