Bugfix/nullpointerexception

Behavioural Patterns/Chain of Responsibility/src/IATMDispenseChain.java

@@ -6,4 +6,12 @@ public void setNextChain(IATMDispenseChain nextChain) {
     }
 
     public abstract void dispense(int amount);
+
+    public void nextChain(int amount) {
+        if (this.nextChain != null) {
+            this.nextChain.dispense(amount);
+        } else {
+            System.out.println("No notes can be dispensed");
+        }
+    }
 }

Behavioural Patterns/Chain of Responsibility/src/Rupee10DispenseChain.java

@@ -6,7 +6,7 @@ public void dispense(int amount) {
             int remainingAmount = amount % 10;
             System.out.println("Number of 10 Rs notes are " + String.valueOf(notes));
         } else if (amount > 0) {
-            this.nextChain.dispense(amount);
+            nextChain(amount);
         }
     }
 }

Behavioural Patterns/Chain of Responsibility/src/Rupee20DispenseChain.java

@@ -7,7 +7,7 @@ public void dispense(int amount) {
             System.out.println("Number of 20 Rs notes are " + String.valueOf(notes));
             this.nextChain.dispense(remainingAmount);
         } else if (amount > 0) {
-            this.nextChain.dispense(amount);
+            nextChain(amount);
         }
     }
 }

Behavioural Patterns/Chain of Responsibility/src/Rupee50DispenseChain.java

@@ -7,7 +7,7 @@ public void dispense(int amount) {
             System.out.println("Number of 50 Rs notes are " + String.valueOf(notes));
             this.nextChain.dispense(remainingAmount);
         } else if (amount > 0) {
-            this.nextChain.dispense(amount);
+            nextChain(amount);
         }
     }
 }