Sample implementation of the Prototype design pattern

I am going to create an abstract Account class and concrete classes extending the Account class. An AccountCache class is defined as a next step, which stores account objects in a HashMap and returns their clone when requested. Create an abstract class implementing the Clonable interface.

    package com.packt.patterninspring.chapter2.prototype.pattern;
    public abstract class Account implements Cloneable{
      abstract public void accountType();
      public Object clone() {
        Object clone = null;
        try {
          clone = super.clone();
        }
        catch (CloneNotSupportedException e) {
          e.printStackTrace();
        }
        return clone;
      }
    }

Now let's create concrete classes extending the preceding class:

Here's the CurrentAccount.java file:

    package com.packt.patterninspring.chapter2.prototype.pattern;
    public class CurrentAccount extends Account {
      @Override
      public void accountType() {
        System.out.println("CURRENT ACCOUNT");
      }
    }

Here's how SavingAccount.java should look:

    package com.packt.patterninspring.chapter2.prototype.pattern;
    public class SavingAccount extends Account{
      @Override
      public void accountType() {
        System.out.println("SAVING ACCOUNT");
      }
    }

Let's create a class to get concrete classes in the AccountCache.java file:

    package com.packt.patterninspring.chapter2.prototype.pattern;
    import java.util.HashMap;
    import java.util.Map;
    public class AccountCache {
       public static Map<String, Account> accountCacheMap =
           new HashMap<>();
       static{
         Account currentAccount = new CurrentAccount();
         Account savingAccount = new SavingAccount();
         accountCacheMap.put("SAVING", savingAccount);
         accountCacheMap.put("CURRENT", currentAccount);
       }
     }

PrototypePatternMain.java is a demo class that we will use to test the design pattern AccountCache to get the Account object by passing a piece of information, such as the type, and then call the clone() method:

    package com.packt.patterninspring.chapter2.prototype
         .pattern;
    public class PrototypePatternMain {
      public static void main(String[] args) {
        Account currentAccount = (Account) 
          AccountCache.accountCacheMap.get("CURRENT").clone();
       currentAccount.accountType();
       Account savingAccount = (Account) 
         AccountCache.accountCacheMap.get("SAVING") .clone();
       savingAccount.accountType();
     }
   }

We've covered this so far and it's good. Now let's look at the next design pattern.