|
public class TestSingleton {
public static void main(String args[]) {
Database database;
database = Database.getInstance("products");
System.out.println("This is the " + database.getName() + " database.");
database = Database.getInstance("employees");
System.out.println("This is the " + database.getName() + " database.");
}
}
class Database {
private static Database singleObject;
private int record;
private String name;
private Database(String n) {
name = n;
record = 0;
}
public static synchronized Database getInstance(String n) {
if (singleObject == null) {
singleObject = new Database(n);
}
return singleObject;
}
public void editRecord(String operation) {
System.out.println("Performing a " + operation + " operation on record " + record
+ " in database " + name);
}
public String getName() {
return name;
}
}
|