What design pattern does the Drivermanager.getconnection () method characterize?
A.
DAO
B.
Factory
C.
Singleton
D.
composition
Explanation:
DriverManager has a factory method getConnection() that returns a Connection
object.
Note 1:A factory method is a method that creates and returns new objects.
The factory pattern (also known as the factory method pattern) is a creational design pattern. A
factory is a Java class that is used to encapsulate object creation code. A factory class instantiates
and returns a particular type of object based on data passed to the factory. The different types of
objects that are returned from a factory typically are subclasses of a common parent class.
Note 2:
The method DriverManager.getConnection establishes a database connection. This method
requires a database URL, which varies depending on your DBMS. The following are some
examples of database URLs: MySQL, Java DB.
I think it was Factory, but, doing some test I realized that really factory methods
Connection conn = DriverManager.getConnection(
“jdbc:hsqldb:hsql://localhost/”, “sa”, “”);
Connection conn2 = DriverManager.getConnection(
“jdbc:hsqldb:hsql://localhost/”, “sa”, “”);
System.out.println(conn == conn2); //prints false
System.out.println(conn.equals(conn2));//prints false
B