Improved Flyweight example comments.

iluwatar · iluwatar · commit 74b43303e389 · 2014-12-26T10:09:53.000+02:00
diff --git a/flyweight/src/main/java/com/iluwatar/AlchemistShop.java b/flyweight/src/main/java/com/iluwatar/AlchemistShop.java
@@ -5,7 +5,8 @@
 
 /**
  * 
- * The class that needs many objects.
+ * AlchemistShop holds potions on its shelves.
+ * It uses PotionFactory to provide the potions.
  * 
  */
 public class AlchemistShop {
@@ -52,6 +53,5 @@ public void enumerate() {
 		for (Potion p : bottomShelf) {
 			p.drink();
 		}
-
 	}
 }
diff --git a/flyweight/src/main/java/com/iluwatar/App.java b/flyweight/src/main/java/com/iluwatar/App.java
@@ -2,9 +2,13 @@
 
 /**
  * 
- * Flyweight (PotionFactory) is useful when there is plethora of objects
- * (Potion). It provides means to decrease resource usage by sharing object
- * instances.
+ * Flyweight pattern is useful when the program needs a huge amount of objects.
+ * It provides means to decrease resource usage by sharing object instances.
+ * 
+ * In this example AlchemistShop has great amount of potions on its shelves.
+ * To fill the shelves AlchemistShop uses PotionFactory (which represents
+ * the Flyweight in this example). Internally PotionFactory holds a map
+ * of the potions and lazily creates new ones when requested.
  * 
  */
 public class App {
diff --git a/flyweight/src/main/java/com/iluwatar/Potion.java b/flyweight/src/main/java/com/iluwatar/Potion.java
@@ -2,7 +2,7 @@
 
 /**
  * 
- * Interface for objects.
+ * Interface for Potions.
  * 
  */
 public interface Potion {
diff --git a/flyweight/src/main/java/com/iluwatar/PotionFactory.java b/flyweight/src/main/java/com/iluwatar/PotionFactory.java
@@ -4,7 +4,10 @@
 
 /**
  * 
- * Flyweight.
+ * PotionFactory is the Flyweight in this example.
+ * It minimizes memory use by sharing object instances.
+ * It holds a map of potion instances and new potions
+ * are created only when none of the type already exists.
  * 
  */
 public class PotionFactory {
@@ -45,5 +48,4 @@ Potion createPotion(PotionType type) {
 		}
 		return potion;
 	}
-
 }
diff --git a/flyweight/src/main/java/com/iluwatar/PotionType.java b/flyweight/src/main/java/com/iluwatar/PotionType.java
@@ -1,5 +1,10 @@
 package com.iluwatar;
 
+/**
+ * 
+ * Enumeration for potion types.
+ *
+ */
 public enum PotionType {
 
 	HEALING, INVISIBILITY, STRENGTH, HOLY_WATER, POISON;
diff --git a/flyweight/src/main/java/com/iluwatar/StrengthPotion.java b/flyweight/src/main/java/com/iluwatar/StrengthPotion.java
@@ -7,5 +7,4 @@ public void drink() {
 		System.out.println("You feel strong. (Potion="
 				+ System.identityHashCode(this) + ")");
 	}
-
 }

Original file line number	Diff line number	Diff line change
`@@ -5,7 +5,8 @@`
`5`	`5`
`6`	`6`	`/**`
`7`	`7`	`*`
`8`		`- * The class that needs many objects.`
	`8`	`+ * AlchemistShop holds potions on its shelves.`
	`9`	`+ * It uses PotionFactory to provide the potions.`
`9`	`10`	`*`
`10`	`11`	`*/`
`11`	`12`	`public class AlchemistShop {`
`@@ -52,6 +53,5 @@ public void enumerate() {`
`52`	`53`	`for (Potion p : bottomShelf) {`
`53`	`54`	`p.drink();`
`54`	`55`	`}`
`55`		`-`
`56`	`56`	`}`
`57`	`57`	`}`
Original file line number	Diff line number	Diff line change
`@@ -2,7 +2,7 @@`
`2`	`2`
`3`	`3`	`/**`
`4`	`4`	`*`
`5`		`- * Interface for objects.`
	`5`	`+ * Interface for Potions.`
`6`	`6`	`*`
`7`	`7`	`*/`
`8`	`8`	`public interface Potion {`
Original file line number	Diff line number	Diff line change
`@@ -4,7 +4,10 @@`
`4`	`4`
`5`	`5`	`/**`
`6`	`6`	`*`
`7`		`- * Flyweight.`
	`7`	`+ * PotionFactory is the Flyweight in this example.`
	`8`	`+ * It minimizes memory use by sharing object instances.`
	`9`	`+ * It holds a map of potion instances and new potions`
	`10`	`+ * are created only when none of the type already exists.`
`8`	`11`	`*`
`9`	`12`	`*/`
`10`	`13`	`public class PotionFactory {`
`@@ -45,5 +48,4 @@ Potion createPotion(PotionType type) {`
`45`	`48`	`}`
`46`	`49`	`return potion;`
`47`	`50`	`}`
`48`		`-`
`49`	`51`	`}`
Original file line number	Diff line number	Diff line change
`@@ -7,5 +7,4 @@ public void drink() {`
`7`	`7`	`System.out.println("You feel strong. (Potion="`
`8`	`8`	`+ System.identityHashCode(this) + ")");`
`9`	`9`	`}`
`10`		`-`
`11`	`10`	`}`