Merge pull request iluwatar#500 from dmitraver/master

iluwatar · web-flow · commit a37a29e12b43 · 2016-10-18T21:01:58.000+03:00
Adds criticism to a Service Locator and Singleton patterns.
diff --git a/service-locator/README.md b/service-locator/README.md
@@ -33,6 +33,12 @@ improves the performance of application to great extent.
 * lookups of services are done quite frequently
 * large number of services are being used
 
+## Consequences
+
+* Violates Interface Segregation Principle (ISP) by providing pattern consumers with an access 
+to a number of services that they don't potentially need.
+* Creates hidden dependencies that can break the clients at runtime.
+
 ## Credits
 
 * [J2EE Design Patterns](http://www.amazon.com/J2EE-Design-Patterns-William-Crawford/dp/0596004273/ref=sr_1_2)
diff --git a/singleton/README.md b/singleton/README.md
@@ -36,6 +36,13 @@ Use the Singleton pattern when
 * [java.lang.System#getSecurityManager()](http://docs.oracle.com/javase/8/docs/api/java/lang/System.html#getSecurityManager--)
 
 
+## Consequences
+
+* Violates Single Responsibility Principle (SRP) by controlling their own creation and lifecycle.
+* Encourages using a global shared instance which prevents an object and resources used by this object from being deallocated.     
+* Creates tightly coupled code that is difficult to test.
+* Makes it almost impossible to subclass a Singleton.
+
 ## Credits
 
 * [Design Patterns: Elements of Reusable Object-Oriented Software](http://www.amazon.com/Design-Patterns-Elements-Reusable-Object-Oriented/dp/0201633612)
