Code comments.

tolerant-reader/src/main/java/com/iluwatar/App.java

@@ -4,7 +4,17 @@ import java.io.IOException;
 
 /**
  * 
+ * Tolerant Reader is an integration pattern that helps creating robust communication
+ * systems. The idea is to be as tolerant as possible when reading data from another
+ * service. This way, when the communication schema changes, the readers must not break.
  * 
+ * In this example we use Java serialization to write representations of RainbowFish
+ * objects to file. RainbowFish is the initial version which we can easily read and
+ * write using RainbowFishSerializer methods. RainbowFish then evolves to RainbowFishV2
+ * and we again write it to file with a method designed to do just that. However, the reader
+ * client does not know about the new format and still reads with the method designed for
+ * V1 schema. Fortunately the reading method has been designed with the Tolerant Reader
+ * pattern and does not break even though RainbowFishV2 has new fields that are serialized.
  *
  */
 public class App {