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Question about the task

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Stuck for 2 h, everting i write is no good... frustred as F...k!🤬🤦‍♂️ Any hint, some good exemple, some good info, tk you!

Read about the Service Locator pattern.

Implement the getService(String jndiName) method in ServiceLocator.
It will implement logic for working with the context and cache.

1) Return the required service from the cache.
2) If the cache doesn't have the required service, then:
2.1) Create the context.
2.2) Get the required service from the context.
2.3) Add the service to the cache and return it.

Requirements:

The ServiceLocator class must have a Service getService(String jndiName) method.
If the required service is in the cache, the getService(String jndiName) method must return the service from the cache.
If the required service is NOT in the cache, the getService(String jndiName) method must create the context.
If the required service is NOT in the cache, the getService(String jndiName) method must find the required service in the context.
If the required service is NOT in the cache, the getService(String jndiName) method must add the service found in the context to the cache and then return it.

package com.codegym.task.task32.task3212; import com.codegym.task.task32.task3212.service.Service; /* Service locator */ public class Solution { public static void main(String[] args) { Service service = ServiceLocator.getService("EJBService"); service.execute(); System.out.println(); service = ServiceLocator.getService("JMSService"); service.execute(); System.out.println(); service = ServiceLocator.getService("EJBService"); service.execute(); System.out.println(); service = ServiceLocator.getService("JMSService"); service.execute(); } }

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Guadalupe Gagnon

Level 37 , Tampa, United States

24 September 2020, 14:05

I would recommend looking at the provided classes. I believe you are looking at the words like Service, Context, Cache from the instructions and getting overwhelmed, but there isn't anything complicated or tricky about it. Consider the starting code while following the numbered instructions: 1) Return the required service from the cache. 2) If the cache doesn't have the required service, then: 2.1) Create the context. 2.2) Get the required service from the context. 2.3) Add the service to the cache and return it. some tips - -- Look at the solution class, it is passing the Strings "EJBService" and "JMSService" to the ServiceLocator.getService() method. This is going to be your (String jndiName) arg of that method. -- The Cache class has 2 methods, getService() and addService(). The first method will either return a service from a String if it exists in the contained List, or null. Use that to decide to return the object if it is valid (doesn't equal null) or to move to step 2 The second method takes in a service and adds it to the map if it is not already there -- Both the EJBService and JMSService classes implement the Service interface, that means they are both objects of a Service -- The context package has the InitialContext class which has one method that takes a string and returns an object of either an EJBServiceImpl or a JMSServiceImpl When you get rid of all the fancy words, this task just has classes talking to classes by passing messages between them using methods. This task literally just uses an ArrayList with user defined add/get helper methods (the Cache class) with 2 utility classes (ServiceLocator and InitialContext) to provide functionality. Don't make it any more complicated than that.

Angel Stefan Arjoca

Level 26 , Bucharest, Romania

25 September 2020, 13:44

So, i return the service from the cache, i create the context and i find the service in context, but i don' t know how to return from context! Any hint for this "problem"? Tk you!

Ramen

Level 23 , South Lake Tahoe, United States

5 January, 04:04

Look at your classes. There is an InitialContext class. Use this to create the context.

InitialContext context = new InitialContext();