From 73c9b9cf95ff944fd1d57bfac0a4faa3a48cdf77 Mon Sep 17 00:00:00 2001
From: Dangoo2002 <kennydangote893@gmail.com>
Date: Thu, 28 Nov 2024 21:50:17 +0300
Subject: [PATCH 1/4] made chnages as per the assignment

---
 src/Lecture1_adt/Transaction1.class           | Bin 0 -> 410 bytes
 src/Lecture1_adt/Transaction2.class           | Bin 0 -> 549 bytes
 src/Lecture1_adt/Transaction2.java            |  23 +--
 src/Lecture1_adt/Transaction3.class           | Bin 0 -> 549 bytes
 src/Lecture1_adt/Transaction3.java            |  18 +-
 src/Lecture1_adt/Transaction4.class           | Bin 0 -> 555 bytes
 src/Lecture1_adt/Transaction4.java            |  21 +--
 .../Transaction4.class                        | Bin 0 -> 569 bytes
 .../Transaction4.java                         |  35 ++--
 .../BankAccount.class                         | Bin 0 -> 475 bytes
 .../BankAccount.java                          |  12 +-
 .../BaseTransaction.class                     | Bin 0 -> 1776 bytes
 .../BaseTransaction.java                      |  58 +++----
 .../DepositTransaction.class                  | Bin 0 -> 997 bytes
 .../DepositTransaction.java                   |  14 ++
 .../DepositTrasaction.java                    |  30 ----
 .../InsufficientFundsException.class          | Bin 0 -> 252 bytes
 .../InsufficientFundsException.java           |   6 +
 .../Main.class                                | Bin 0 -> 1597 bytes
 .../Main.java                                 |  27 +++
 .../TransactionInterface.class                | Bin 0 -> 315 bytes
 .../TransactionInterface.java                 |  15 +-
 .../WithdrawalTransaction.class               | Bin 0 -> 1412 bytes
 .../WithdrawalTransaction.java                |  49 ++----
 src/Main.java                                 | 156 ------------------
 25 files changed, 132 insertions(+), 332 deletions(-)
 create mode 100644 src/Lecture1_adt/Transaction1.class
 create mode 100644 src/Lecture1_adt/Transaction2.class
 create mode 100644 src/Lecture1_adt/Transaction3.class
 create mode 100644 src/Lecture1_adt/Transaction4.class
 create mode 100644 src/Lecture2_adt_specification/Transaction4.class
 create mode 100644 src/Lecture4_interfaces_abstract_classes/BankAccount.class
 create mode 100644 src/Lecture4_interfaces_abstract_classes/BaseTransaction.class
 create mode 100644 src/Lecture4_interfaces_abstract_classes/DepositTransaction.class
 create mode 100644 src/Lecture4_interfaces_abstract_classes/DepositTransaction.java
 delete mode 100644 src/Lecture4_interfaces_abstract_classes/DepositTrasaction.java
 create mode 100644 src/Lecture4_interfaces_abstract_classes/InsufficientFundsException.class
 create mode 100644 src/Lecture4_interfaces_abstract_classes/InsufficientFundsException.java
 create mode 100644 src/Lecture4_interfaces_abstract_classes/Main.class
 create mode 100644 src/Lecture4_interfaces_abstract_classes/Main.java
 create mode 100644 src/Lecture4_interfaces_abstract_classes/TransactionInterface.class
 create mode 100644 src/Lecture4_interfaces_abstract_classes/WithdrawalTransaction.class
 delete mode 100644 src/Main.java

diff --git a/src/Lecture1_adt/Transaction1.class b/src/Lecture1_adt/Transaction1.class
new file mode 100644
index 0000000000000000000000000000000000000000..25224be4466ce95dc313926d4f707809f349e756
GIT binary patch
literal 410
zcmZvYPfNo<5XIjlX=Br9|JZ74y?9H57<v+^cqs^lpa+Xr*(Qsmq#KAEzn6z9co5Hi
zC~*=m1-<O-8{WMA?R<T|e*iegu>%|32I|;%V4-KDUy1`8hc*U;x>#q0(gd0ltXODC
z=!GlsEP_HOX)qJ1RI$jXY`siWqOS-8Z~mWSe9sB9Earq(m?(Kutd}xhh-Jzh=PoPq
zNM0wU=qz%fo<yXROij+p$6UA=y4XR(#Sun??q38K4w{5vC?j3ua`GTz9c(8N+SODl
z)MIeFT(OT}dL>saN;6e{%^UxsZ+WIT;f>h5E(25|@Qs1dtST|tF6%v37wj;(_Wd`I
mKia_XPhVkv!rGwrQrTO4c6rg@0She-Yomt_2ei3opz{Om{Zy3z

literal 0
HcmV?d00001

diff --git a/src/Lecture1_adt/Transaction2.class b/src/Lecture1_adt/Transaction2.class
new file mode 100644
index 0000000000000000000000000000000000000000..036f6d65966ebfd695851c6c348e9e1a49d52828
GIT binary patch
literal 549
zcmZutT}#4X7(K6ZF6T;J=12BPH!6`-7hM=Z7=a*lk#rlcI%G08SX;lUi-IiZBD(HJ
zMQ2(e<;{7vvvbaK_I!N4z5zJGmJSX1BoZh@P}HHKq+wM<S;Lw@LXN!94Fp6>Al{dO
zC6H?m<(;gDf$h|r(y`pW^c$2O+pZm)2ox)=d5Y>a6PjM13F)@&S{LD{Yxy17b;u+K
zR&e^gN~u)2Oe1qP*_W?W=j93LS6=A%taCd`$aZ|`-pXEJd+xzr)X;!|bps1X8qkq4
zuz^hh^M84PQrqeUp>OTq$bL|tO%ljV432aM^~>&%IsrE1&!|1ebEA9w^qbK%u+4L7
zym1U>RDn-s)PhriV6#Qy65kG~P&m`I7l>MUj96`V4CRp&4@EQ)CuWHzW0q;k@k@rx
tG+>=mP@&eI5WD}iB_?EnXwo#5?r=uZ6s5{D;_px&{us&><jBRa@&y!XXbJ!T

literal 0
HcmV?d00001

diff --git a/src/Lecture1_adt/Transaction2.java b/src/Lecture1_adt/Transaction2.java
index 6c7a010..274b8f7 100644
--- a/src/Lecture1_adt/Transaction2.java
+++ b/src/Lecture1_adt/Transaction2.java
@@ -1,36 +1,29 @@
 package Lecture1_adt;
 
-import org.jetbrains.annotations.NotNull;
-
 import java.util.Calendar;
-//import java.util.Date;
 
 /**
- * This Lecture1_adt.Transaction2 Class Takes the first step to resolves the ADT design issues of Transaction1:
+ * This Lecture1_adt.Transaction2 Class takes the first step to resolve the ADT design issues of Transaction1:
  * 1. Representation Independence: --- Encapsulation - Providing access methods to the internal data.
- *                                     External client code only access via allowable operations
- *                                 --- Changes to internal representation can still be accessed via same methods defined
- *
- * 2. Preservation of Invariants: --- Access Modifies private final makes the data Unchangeable
+ *                                     External client code only accesses via allowable operations
+ *                                 --- Changes to internal representation can still be accessed via the same methods defined
  *
- * Lecture1_adt
+ * 2. Preservation of Invariants: --- Access modifies private final fields to make the data unchangeable
  */
-
 public class Transaction2 {
     private final int amount;
     private final Calendar date;
 
-    public Transaction2(int amount, @NotNull Calendar date) {
+    public Transaction2(int amount, Calendar date) {
         this.amount = amount;
-        this.date = date;
+        this.date = date; // Defensive copying not required for constructor arguments in this class
     }
 
     public int getAmount() {
-        return amount; // Because we are dealing with Value types we need not worry about what we return
+        return amount; // Value types like integers can be returned directly
     }
 
     public Calendar getDate() {
-//        return date;    // Because we are dealing with Reference types we need to judiciously copy what our getters return
-        return (Calendar) date.clone(); // Defensive copying or Judicious Copying
+        return (Calendar) date.clone(); // Defensive copying ensures reference types are not altered externally
     }
 }
diff --git a/src/Lecture1_adt/Transaction3.class b/src/Lecture1_adt/Transaction3.class
new file mode 100644
index 0000000000000000000000000000000000000000..f24dc62ce5284665aed0a392aa359e1359b07667
GIT binary patch
literal 549
zcmZutO-sW-6r63E#>Vu+sI9fu54^NREaJgKMUaY6D0)!5$~Fll5)+7tzsiGxAK*be
z`=i9!Ql+SudAqao=FPs3&(}8qdssJNppr)pRRv2Xbkqzi8>kyt5y;8wC=C+<(HF?N
zGVuf!23PV{cGAQTIz1V9p)2DqrTc#9CkFyc&HjIi)&(7UkxPftzz@BX^m^#U=W-a3
z$&b9`a5743wm8fnb2Oe;X}13J6EM%BG<LjWUpdU3$1=Q;PU1)5?zT#3!9v5r4DuFC
z%vxB*nt=T`yg+T>IY}COJD1W;I@3-9<#9tG!%^pSctxE66Y?{<6GWlf$9KLdO&1$n
zr@<X(V5<l`*(wFA2Ek+nVv)C9Dm2zo`vsz1e?q3c^#tvK6c<IbktG(0McR~zWxkX#
uH!*0i3M%yWBQkeCZMiWyPqd*>&DvyD(pgHiXJp@@-~Vc;Qm{ZSgT*fnz-ROT

literal 0
HcmV?d00001

diff --git a/src/Lecture1_adt/Transaction3.java b/src/Lecture1_adt/Transaction3.java
index 48781e7..ef47946 100644
--- a/src/Lecture1_adt/Transaction3.java
+++ b/src/Lecture1_adt/Transaction3.java
@@ -1,31 +1,25 @@
 package Lecture1_adt;
 
-import org.jetbrains.annotations.NotNull;
-
 import java.util.Calendar;
 
 /**
- * There is still Exposure seen in Transaction2 I that if we make next payment the date of first payment is also altered
- * This Class Transaction3:Adds Code to correct this exposure:
- * Intentional review of any methods that receive produces (returns)
- *              If produces interface of a method deals with objects or any reference types,
- *              there is need to perform defensive copying to enhance Invariant preservation
+ * This Lecture1_adt.Transaction3 class adds code to correct potential exposure issues in Transaction2.
+ * Methods that return objects of reference types use defensive copying to enhance invariant preservation.
  */
 public class Transaction3 {
     private final int amount;
     private final Calendar date;
 
-    public Transaction3(int amount, @NotNull Calendar date) {
+    public Transaction3(int amount, Calendar date) {
         this.amount = amount;
-        this.date = date;
+        this.date = date; // Defensive copying not required for constructor arguments in this class
     }
 
     public int getAmount() {
-        return amount; // Because we are dealing with Value types we need not worry about what we return
+        return amount; // Value types like integers can be returned directly
     }
 
     public Calendar getDate() {
-//        return date;    // Because we are dealing with Reference types we need to judiciously copy what our getters return
-        return (Calendar) date.clone(); // Defensive copying or Judicious Copying
+        return (Calendar) date.clone(); // Defensive copying ensures reference types are not altered externally
     }
 }
diff --git a/src/Lecture1_adt/Transaction4.class b/src/Lecture1_adt/Transaction4.class
new file mode 100644
index 0000000000000000000000000000000000000000..1533774de52cb607100ede3cfcbd2520e8e23b8f
GIT binary patch
literal 555
zcmZuuOG^S#6#lNSNu5e3pV^Z(Dv<<1gb{=h2vUorZCsr}M#dSKX8Khv3bLR@wC+bm
z-!%&<H|NYf_j}zlAD^#p01mO0f`&p82^3R^p`@X#4yzg}8rB37a^!_>ARyWTF;fPX
zK&~^Ccd`)%w$o@y$8t^SHwitqT{}1tC{^3@5VdP6v^<jv%N^UbF2YgI^1HI<aFQHY
z!Rgd0TCLGc<K%4OSE$zJ=?SE+ywLAk=eAPFc75sI%6?#b?!lf)s6)rPjs+xjY+zHs
z_@7%x3Tc6I$La^6Z|&bmGib~z31lWLN4kT?Wp7BF02A^t@xJ4^Y9BxOW-v``bB!8z
z9D$)C@XJtM>`@3NTV!40>4=CZd%pexQLl^<sqa1``i|Hb@kd^8U91NG4oHfTl;k9b
w3~w^XPG#2F1rhQ36C(G&w8Uh%!fHTO<+#JHplL$m-&PNQ2t@*NoJElT0!kHWh5!Hn

literal 0
HcmV?d00001

diff --git a/src/Lecture1_adt/Transaction4.java b/src/Lecture1_adt/Transaction4.java
index f09b0d8..2c8fd9d 100644
--- a/src/Lecture1_adt/Transaction4.java
+++ b/src/Lecture1_adt/Transaction4.java
@@ -1,32 +1,25 @@
 package Lecture1_adt;
 
-import org.jetbrains.annotations.NotNull;
-
 import java.util.Calendar;
+
 /**
- * There is still Exposure seen in Transaction3 in that if we make a list of 12 payments,
- *                 the date of all payments remain the same.
- * This Class Transaction4:Adds Code to correct this exposure:
- * In Making th List of 12 Transactions, we are constantly using the constructor which takes a Date Object
- * Intentional review of any methods that receives or requires (i.e. takes in as parameters)
- *              If requires interface of a method deals with objects or any reference types,
- *              there is need to perform defensive copying to enhance Invariant preservation
+ * This Lecture1_adt.Transaction4 class ensures that both constructor arguments and method returns use defensive copying.
+ * This prevents unintended side effects when dealing with reference types.
  */
 public class Transaction4 {
     private final int amount;
     private final Calendar date;
 
-    public Transaction4(int amount, @NotNull Calendar date) {
+    public Transaction4(int amount, Calendar date) {
         this.amount = amount;
-        this.date = (Calendar) date.clone();  // Defensive copying or Judicious Copying for Requires interfaces
+        this.date = (Calendar) date.clone(); // Defensive copying for constructor arguments
     }
 
     public int getAmount() {
-        return amount; // Because we are dealing with Value types we need not worry about what we return
+        return amount; // Value types like integers can be returned directly
     }
 
     public Calendar getDate() {
-//        return date;    // Because we are dealing with Reference types we need to judiciously copy what our getters return
-        return (Calendar) date.clone(); // Defensive copying or Judicious Copying for produces Interfaces
+        return (Calendar) date.clone(); // Defensive copying ensures reference types are not altered externally
     }
 }
diff --git a/src/Lecture2_adt_specification/Transaction4.class b/src/Lecture2_adt_specification/Transaction4.class
new file mode 100644
index 0000000000000000000000000000000000000000..d18d0c9154e13fc5c02db9746804f817998d9e37
GIT binary patch
literal 569
zcmZuu+e*Vg6rAlXw#Hj}v0my01=}JPL=dS6q6k9K2aB&|o314i6G;=l$_E9j;Dh+=
zM~Snoil_wUWY5l-nVh`6KfeIj#!?0b3TdP;ok0Rc12g(CYhcd6yg*7``H>e2h+~07
zM}|ru*SM57vKEDoTRV`h@;Wl8le+78PPivfEFb^JsGL*b!0%9DqTzVzB)V#=pefrf
zJL#?p_dl)T<qFLVb`A%Ag>vOTJ%P-b9|g8La<sx!Gmu_S+M(lnTN^r|2@@p~BS@QA
zz@mWlH@ArlMg`Uy$_}GIZMI}5Z1t{{?OZsv)LONlx&o5}4Oe>I+G+ceQv%G(PfOaa
z@9FJ)rTxLFW0^}exbYY)9f)t1c4m!3Fy|O?oTnW!;;i}V6GU~ck63m65%E_f`bggM
zg3BXX{8vNFQY^<O&znh1eae(r1sTce17f$|W2r%No@gOU)Q&5xnmS5qa%gq;Yhaax
J9D6b3KLD9OZ+`#)

literal 0
HcmV?d00001

diff --git a/src/Lecture2_adt_specification/Transaction4.java b/src/Lecture2_adt_specification/Transaction4.java
index be8a1eb..6e35b4e 100644
--- a/src/Lecture2_adt_specification/Transaction4.java
+++ b/src/Lecture2_adt_specification/Transaction4.java
@@ -1,47 +1,38 @@
 package Lecture2_adt_specification;
 
-import org.jetbrains.annotations.NotNull;
-
 import java.util.Calendar;
-//import java.util.Date;
 
 /**
- * In Addition to the Design considerations in Transaction4 class:
- * This class adds Specifications defining the Requires and Produces interfaces
+ * This Lecture2_adt_specification.Transaction4 class extends the design considerations of the previous Transaction4 class.
+ * It adds specifications for the requires and produces interfaces.
  */
-
 public class Transaction4 {
     private final int amount;
     private final Calendar date;
 
     /**
-     * Lecture1_adt.TransactionInterface Constructor
-     * @param amount in an integer
-     * @param date: Not null, and must be a Calendar object
-     * @return void
-     * Instialises the field, attributes of a transaction
-     * Creates a object of this
+     * Constructor for Transaction4
+     * @param amount the transaction amount (must be an integer)
+     * @param date the transaction date (must be a Calendar object and not null)
      */
-    public Transaction4(int amount, @NotNull Calendar date) {
+    public Transaction4(int amount, Calendar date) {
         this.amount = amount;
-        this.date = (Calendar) date.clone();
+        this.date = (Calendar) date.clone(); // Defensive copying ensures input reference is not shared
     }
 
-
     /**
-     * getAmount()
-     * @return integer
+     * Retrieves the transaction amount.
+     * @return an integer representing the amount
      */
     public int getAmount() {
-        return amount; // Because we are dealing with Value types we need not worry about what we return
+        return amount; // Value types like integers can be returned directly
     }
 
     /**
-     * getDate()
-     * @return Calendar Object
+     * Retrieves the transaction date.
+     * @return a Calendar object representing the transaction date
      */
     public Calendar getDate() {
-//        return date;    // Because we are dealing with Reference types we need to judiciously copy what our getters return
-        return (Calendar) date.clone(); // Defensive copying or Judicious Copying
+        return (Calendar) date.clone(); // Defensive copying ensures reference types are not altered externally
     }
 }
diff --git a/src/Lecture4_interfaces_abstract_classes/BankAccount.class b/src/Lecture4_interfaces_abstract_classes/BankAccount.class
new file mode 100644
index 0000000000000000000000000000000000000000..14c015ec3771a88bc9435bae84e65468be3de528
GIT binary patch
literal 475
zcmY+9%}&BV6ot>Ug+c-ORaY)t6}ph68#NJ$D}NRk5|`6qf(2{|6nPXEK7=vRn7Hr(
zd?@27Qlg8_+|E7UIrn~je|!Qs#I6GiwLDDJZ8U6b3)sG#$WUnk(G|!Z1z`}M2w2T-
ztIz8!8n9Kq2ts|excBw!M*0)JI71zGQqpX;$l3!vjpjitkXr`v-C!n{0;OIo)%a3Q
zQ?3^+W=fw2iAkj+!||z7(ISiwM)E-xVPmI=46*`+KTS%LcAJw9+t>a`E2c2DkA3c9
zaW?@Y!B|<WZRB|7`RB23@^-v;2+w_k@v>4oJhxUIi$sRnEQtb&Yi^Hzf|`u?3gdZ$
zBqC7E#WoQx@g$<)-BRnSe;E#aK(WI#!7rWbcnviYfA{eTrC)lurVSG5gjELCP)7r0
OzL^kpT2)vYsQv(CzDC*r

literal 0
HcmV?d00001

diff --git a/src/Lecture4_interfaces_abstract_classes/BankAccount.java b/src/Lecture4_interfaces_abstract_classes/BankAccount.java
index 28d0d07..37b8bf4 100644
--- a/src/Lecture4_interfaces_abstract_classes/BankAccount.java
+++ b/src/Lecture4_interfaces_abstract_classes/BankAccount.java
@@ -1,7 +1,7 @@
 package Lecture4_interfaces_abstract_classes;
-
 public class BankAccount {
     private double balance;
+
     public BankAccount(double balance) {
         this.balance = balance;
     }
@@ -10,7 +10,13 @@ public double getBalance() {
         return balance;
     }
 
-    public void setBalance(double balance) {
-        this.balance = balance;
+    public void deposit(double amount) {
+        balance += amount;
+    }
+
+    public void withdraw(double amount) {
+        if (balance >= amount) {
+            balance -= amount;
+        }
     }
 }
diff --git a/src/Lecture4_interfaces_abstract_classes/BaseTransaction.class b/src/Lecture4_interfaces_abstract_classes/BaseTransaction.class
new file mode 100644
index 0000000000000000000000000000000000000000..b6d95202b4945c187a94874680d08fa66fd21775
GIT binary patch
literal 1776
zcmaJ>YjfK~6g}(2mhGsxRh@*kB)DxJj-heOt5BChVw2XzeSlrc<I~1o5;d~qk>t$e
zpYShu3@tPH!0?$L#c)<qiJW*C&FpG-&%Ni~bMNlo{~Z4b;5NQ5qJ;GV-axg8S!@`n
z>BT#Gc(;HX*tCdyuZZ{Yfdzq&H0rj63_i)@j)8`Oy9PcL$jPBMc0&Qt5||yxPzjVf
zFXW-Dk3-w3H>IQ8f%F>!=R#k)f$WF2=eCKqVwfY{y?QtFZFi5L++EwX!+Qd?YHOOC
zvo;&wkhtj$NL=dJu6jHk?kc}0cOC8&_Efl)L^xC3AgjThRutw!bz>TXz<EM?ld+ax
zV<)3s95L)PwxvR8JAnYn7*|$~M$QpERy*6$J=p5^wO9>(RP1_Vzpr*|9cFo31}a6l
zsRcB#h-)S;z%p?UpHZ;0vYNPvvWa;t82H@87Pd*Y?RjB9u}6<oxbF>uQVz{LS|+~0
zj)D6o9-y7aL%sgeL<f)Zc&rys1h#Y_l~kcBIs;n`HY?rnZr_nXpn^)U?~R>7#XD5K
zZx4vyw}Z+sBHLsYP9?*LqQE2Rp6tF*eYQ(Em2KM%mH(scQ;2Ne@mwv)gx;|cyCdbO
zdlZCfNTIzk-Ob09w7vRMT@kjElEX$3Pw|z&g%nq%-MUi|0*ga=pqifBm*I0e+~;2q
zN;hQX)~Zu_?Ch4n#VD&uO7>UO5{}E5ra5Be3vok6Va!)sNfS;smhRG?J){!WYbB!V
zq&t^77<!HztRy5Sr&IhH_*&PO+$$%Qu-!xNKqWUXR$_;j)ANrEe9Md2@w|iaNWg5n
zuJW64=>>jDXO;Mf`|N>q2aXC>V#CH+$x=HLhP|VangahJg-<#lom=994~)~bsfvN`
z1Xj=FH!U`S<^RXwD&N5p-@Wsgfu*k?UqegZwP@yb<DBF9BHrY9iK`}&S<Y8#e?ZjM
zUm{bx@d`74VfH1mwM!gxzw%h%GRK7on&+EZ;8&#EIqsW0y@IzAhf92H1+m%M@5uc8
zpQ&aA;}TfHass{1S?|sfnvF?+Ib|?Uz}u)K21|*7_MJNoz0AX_xRyYlF)!`=)^9L0
z`WSiO6$<e(bIj;ZmL#7$W*&OyBwLGlg6t*oFVpqS$oX}wBowR6G(&{;X`P!eEk*}x
l<XmSQs|01RhG(3MH16U#dQ`v8b(!ZkxpylXKa9qY{{^4btM32+

literal 0
HcmV?d00001

diff --git a/src/Lecture4_interfaces_abstract_classes/BaseTransaction.java b/src/Lecture4_interfaces_abstract_classes/BaseTransaction.java
index ed81eb8..f59feee 100644
--- a/src/Lecture4_interfaces_abstract_classes/BaseTransaction.java
+++ b/src/Lecture4_interfaces_abstract_classes/BaseTransaction.java
@@ -1,51 +1,41 @@
 package Lecture4_interfaces_abstract_classes;
-
-import org.jetbrains.annotations.NotNull;
-
 import java.util.Calendar;
 
-public abstract class BaseTransaction implements TransactionInterface {
-    private final int amount;
+public class BaseTransaction implements TransactionInterface {
+    private final double amount;
     private final Calendar date;
     private final String transactionID;
 
-    /**
-     * Lecture1_adt.TransactionInterface Constructor
-     * @param amount in an integer
-     * @param date: Not null, and must be a Calendar object
-     * @return void
-     * Instialises the field, attributes of a transaction
-     * Creates a object of this
-     */
-    public BaseTransaction(int amount, @NotNull Calendar date)  {
+    public BaseTransaction(double amount, Calendar date, String transactionID) {
         this.amount = amount;
-        this.date = (Calendar) date.clone();
-        int uniq = (int) Math.random()*10000;
-        transactionID = date.toString()+uniq;
+        this.date = (Calendar) date.clone(); // Defensive copying
+        this.transactionID = transactionID;
     }
 
-    /**
-     * getAmount()
-     * @return integer
-     */
+    @Override
     public double getAmount() {
-        return amount; // Because we are dealing with Value types we need not worry about what we return
+        return amount;
     }
 
-    /**
-     * getDate()
-     * @return Calendar Object
-     */
+    @Override
     public Calendar getDate() {
-//        return date;    // Because we are dealing with Reference types we need to judiciously copy what our getters return
-        return (Calendar) date.clone(); // Defensive copying or Judicious Copying
+        return (Calendar) date.clone(); // Defensive copying
+    }
+
+    @Override
+    public String getTransactionID() {
+        return transactionID;
+    }
+
+    @Override
+    public void printTransactionDetails() {
+        System.out.println("Transaction ID: " + transactionID);
+        System.out.println("Amount: " + amount);
+        System.out.println("Date: " + date.getTime());
     }
 
-    // Method to get a unique identifier for the transaction
-    public String getTransactionID(){
-        return  transactionID;
+    @Override
+    public void apply(BankAccount ba) {
+        System.out.println("Base transaction applied. Subclasses should override this method.");
     }
-    // Method to print a transaction receipt or details
-    public abstract void printTransactionDetails();
-    public abstract void apply(BankAccount ba);
 }
diff --git a/src/Lecture4_interfaces_abstract_classes/DepositTransaction.class b/src/Lecture4_interfaces_abstract_classes/DepositTransaction.class
new file mode 100644
index 0000000000000000000000000000000000000000..0d320fb16efe62de99f4b178cd7df7f004506be7
GIT binary patch
literal 997
zcmaJ=?QRl56g>l!h3#69T3h_6t%3z=i{EX;n6!{a6Z}XZ^@qO(c0#u-Gn?I^32)+S
z=nqW#!w2x8jCWa*(m>2+Co}is+;h*|`SbVkH-G~inn>ZM2?IG3tGJcM8gA#vb;rbA
z+%s_Bz$QcTts@=%j-gU&G|%}3uMV~2R_ojq(&m0GvbkLLsx9q1vR5mgG9>EC77UrD
zBgLoTpd<V?@3>@H;-2S@7_z12F_-<LZdVPZp5&M<HT1jU#0lfp8^Tk8quV~00q<%@
z$^Edpg)~eH53prm+rmRUGElHk#ACudR!Rrj=iW!5&y*cxlGsV1WTA|Tfn5tvu*Z;_
zhbE@SJP<R*7}7nVj|L$-hIpymU|61E%wX6NLu$6v2z$;>)QOZB1zHR!PYo%1Ez-zQ
z)h{HFCYb~u)J*K7%3w{|2>Z<zqrL~cFX~Emx&G?tGuj23OC1mjRhbu?VRcgWIykZO
z!cwjb^X9Y4rv{#evb<y{T+w#qh3bpxJw_x>NPFdv47{dMXe!kodc^sIl)|sOJO~6a
z`#xJ?iV@wwdoFEP1cfMZ!K}<syO!7<d168Mx0(3QopaHp$(b=tA!s(;mZL?@zyU*X
zuD?ax7&iYOhi!T(DS9423^W}uX<epM5li#|>B`PtKJg3e2OUTwT1^TCIa5fI<px%!
zDTjzpJR7@}F=AuHe<Bg?E<>O(l2-^T6dB^AsMI=P#*v|O3|YLG*cqPT6`mtcUQiUn
H2L1Vey8Zx0

literal 0
HcmV?d00001

diff --git a/src/Lecture4_interfaces_abstract_classes/DepositTransaction.java b/src/Lecture4_interfaces_abstract_classes/DepositTransaction.java
new file mode 100644
index 0000000..db15e3e
--- /dev/null
+++ b/src/Lecture4_interfaces_abstract_classes/DepositTransaction.java
@@ -0,0 +1,14 @@
+package Lecture4_interfaces_abstract_classes;
+import java.util.Calendar;
+
+public class DepositTransaction extends BaseTransaction {
+    public DepositTransaction(double amount, Calendar date, String transactionID) {
+        super(amount, date, transactionID);
+    }
+
+    @Override
+    public void apply(BankAccount ba) {
+        ba.deposit(getAmount());
+        System.out.println("Deposited: " + getAmount());
+    }
+}
diff --git a/src/Lecture4_interfaces_abstract_classes/DepositTrasaction.java b/src/Lecture4_interfaces_abstract_classes/DepositTrasaction.java
deleted file mode 100644
index 81afab5..0000000
--- a/src/Lecture4_interfaces_abstract_classes/DepositTrasaction.java
+++ /dev/null
@@ -1,30 +0,0 @@
-package Lecture4_interfaces_abstract_classes;
-
-import org.jetbrains.annotations.NotNull;
-
-import java.util.Calendar;
-
-public class DepositTrasaction extends BaseTransaction {
-    public DepositTrasaction(int amount, @NotNull Calendar date){
-        super(amount, date);
-    }
-    private boolean checkDepositAmount(int amt){
-        if (amt < 0){
-           return false;
-        }
-        else{
-            return  true;
-        }
-    }
-
-    // Method to print a transaction receipt or details
-    public void printTransactionDetails(){
-        System.out.println("Deposit Trasaction: "+this.toString());
-    }
-
-    public void apply(BankAccount ba){
-        double curr_balance = ba.getBalance();
-        double new_balance = curr_balance + getAmount();
-        ba.setBalance(new_balance);
-    }
-}
diff --git a/src/Lecture4_interfaces_abstract_classes/InsufficientFundsException.class b/src/Lecture4_interfaces_abstract_classes/InsufficientFundsException.class
new file mode 100644
index 0000000000000000000000000000000000000000..c4dddd2fc690bc832531a9bd86c0ef245ed0c60a
GIT binary patch
literal 252
zcmX^0Z`VEs1_pBmUM>b^1}=66ZgvJ9Mg}&U%)HDJJ4Oak4WF#UvPAuy#JqI<;F6-u
zymV{LFh&Lz=lqmZMh1SL%)C^;(%hufqL9R-9H0nSaDHh~a;jS<h$HWrS6rHwmYJNH
znpfghnwL`ST9KSuP?DLSrw1~Yhk=EGm61UTw=zZsVTAo~%?yeROhD&?03#3r4FQsD
mK%Np%oC!#?X=!g~VB83nX9tp8U{PkEIu@Wx4xk7V11A8AcsaiS

literal 0
HcmV?d00001

diff --git a/src/Lecture4_interfaces_abstract_classes/InsufficientFundsException.java b/src/Lecture4_interfaces_abstract_classes/InsufficientFundsException.java
new file mode 100644
index 0000000..97176e3
--- /dev/null
+++ b/src/Lecture4_interfaces_abstract_classes/InsufficientFundsException.java
@@ -0,0 +1,6 @@
+package Lecture4_interfaces_abstract_classes;
+public class InsufficientFundsException extends Exception {
+    public InsufficientFundsException(String message) {
+        super(message);
+    }
+}
diff --git a/src/Lecture4_interfaces_abstract_classes/Main.class b/src/Lecture4_interfaces_abstract_classes/Main.class
new file mode 100644
index 0000000000000000000000000000000000000000..4318851c6f99dce5f20d61d4de0adbd3e907efca
GIT binary patch
literal 1597
zcmaJ>ZFdtz6n-Xcchc>az?QTi0;v>DOWU-dfCMo#u~1D4k|-d)O*TVWvf0hqos`oL
z>QC^i{sKSaht@;S@dx-9{4X5u?8cJX9QVV_?49S{dG2%X%wMlx{R!Y2q=|FLbIcp1
zpG#x`Or)^DamgtC^siwNOKB{dFi_CLiXK+SaT!-M_<ftauABG}H#mw$$<<MSG;W%(
zwTG=eY^>T~8fW8{O>WoIC~@58SYt45y1uJ!F^uHrzhoFK2QA5vsk*-0>~)$lY>1{u
zmeG!IeTM1$lj?J^Eef9Sw+eL?y8c#CJ5JV>aN0G|?c>dQ&<h>8?rP`p8aXd(KMUuP
zW0+VIe*3oL1U+AAQ<=f8$Zin1su2o55{_~MpQB>o6Rb0gH6E?3tZL*P3wM#Tuz^oG
zKC@6o&B7+`F&tkD0u`xHbZb&Q3tCae!2L8nx9|XUj)sLVKt!_-UG=OLiWkBgII4fd
z<uo2zc!bAkd_@r-$ZZ)$!pl7slt*isWYC$=&KnKxHJ?jI(N4aib+F@|o^riHS$NWK
ziICFWl4`?`l<*x=V>&;dXm|)!WLU^ohHVTNe5Om<52{s>idaUJiRgB{9U_^p4#*r=
zX@GZqCsMLQbq{*PKARlk28H`NEEQIY4pB0R`I?|&YvR-*6%$YJHAAjnyj(Nc%!#K;
zhPhT!!y7rqFw+rjSq^+hC@ndyv;c|-W=X1}Nij^t+8yS=z~e+cQazhL>ZLWmFr3Vb
zgF?rAco<ic^7yYXRO;E`ArcqiQ2>r_bSDXhxi`gk{q3MF`}ZKpb)9-Q2zNLfx?I&D
zX!p7d)`suPu<VH_k|e+{gNgKGBu#r)_$^OHbBSZ|XuboMLynD|t{eg%ysb&676+y8
zhoDaN>aLPSjuykkBl!*E#&GWcahSzfdg1h!qUVS1J&m*Uca~;G^Vq^3*h^Y4yhEcA
z8%HpX3z(y|hW<^~QJR0;N9yrOjO<~ox(|bv{11%V<{l<$i@UHEFYRLTcO0WB^9sj-
zU7Xm5O}HtI%kE)%b7>bdO9VJ|fIA)IwC$~5kv%Y<iOs)Zf-Lsi6iIVT#T>6<lGbCG
z0LK}6XU`McIr_Uo_A-v)4l?v2ouE511qUb5!!&-tDO@D43{tPr<4AEB95%-Y-i-sl
fhwo`NDdlg`#CJH259pt=#Z|Ihi^q@R@#B90+7gY!

literal 0
HcmV?d00001

diff --git a/src/Lecture4_interfaces_abstract_classes/Main.java b/src/Lecture4_interfaces_abstract_classes/Main.java
new file mode 100644
index 0000000..3bb0cad
--- /dev/null
+++ b/src/Lecture4_interfaces_abstract_classes/Main.java
@@ -0,0 +1,27 @@
+package Lecture4_interfaces_abstract_classes;
+import java.util.Calendar;
+
+
+public class Main {
+    public static void main(String[] args) {
+        BankAccount account = new BankAccount(1000);
+
+        DepositTransaction deposit = new DepositTransaction(500, Calendar.getInstance(), "TX001");
+        deposit.printTransactionDetails();
+        deposit.apply(account);
+
+        System.out.println("Account balance after deposit: " + account.getBalance());
+
+        WithdrawalTransaction withdrawal = new WithdrawalTransaction(200, Calendar.getInstance(), "TX002");
+        withdrawal.printTransactionDetails();
+        withdrawal.apply(account);
+
+        System.out.println("Account balance after withdrawal: " + account.getBalance());
+
+        if (withdrawal.reverse(account)) {
+            System.out.println("Account balance after reversal: " + account.getBalance());
+        } else {
+            System.out.println("Reversal failed.");
+        }
+    }
+}
diff --git a/src/Lecture4_interfaces_abstract_classes/TransactionInterface.class b/src/Lecture4_interfaces_abstract_classes/TransactionInterface.class
new file mode 100644
index 0000000000000000000000000000000000000000..9746b4d690b0b21b0a9d9bf83bbe5612b6f69cd0
GIT binary patch
literal 315
zcmZvXO-chn5QSgGOvc2&2%>m{nT@k_kyUgMgn)~P`?76^j&0A-sS&)I3lHF-B$Wms
z3pf3ms#o>C`uY9(25^nj949%ZgmGhK{@(UM2zy0Y6LPK8ES7Lyl#3OAaMg?R)h&A)
zUO3JOQ?)!s4r?~z+HkK^XMbMLp{bS<U1-#K(dlQ`TU%l0*D36Yka5@fPu*B7ZaBQn
zjoG5iN^MP+Z6A%jb6!y{cjJQC_{zp!ZQ(Tfzn-p4=n3cHd1Z}^2!w&24`f3Hzz|T)
WFiM(ZKj|2gqz5=uC*ern0ggAXluoz+

literal 0
HcmV?d00001

diff --git a/src/Lecture4_interfaces_abstract_classes/TransactionInterface.java b/src/Lecture4_interfaces_abstract_classes/TransactionInterface.java
index 5902713..48544cb 100644
--- a/src/Lecture4_interfaces_abstract_classes/TransactionInterface.java
+++ b/src/Lecture4_interfaces_abstract_classes/TransactionInterface.java
@@ -1,21 +1,10 @@
 package Lecture4_interfaces_abstract_classes;
 import java.util.Calendar;
 
-/**
- * Interface for Transactions
- * Any class that defines a transaction is expected to implement this Interface
- */
 public interface TransactionInterface {
-
-    // Method to get the transaction amount
     double getAmount();
-
-    // Method to get the transaction date
     Calendar getDate();
-
-    // Method to get a unique identifier for the transaction
     String getTransactionID();
-
+    void printTransactionDetails();
+    void apply(BankAccount ba);
 }
-
-
diff --git a/src/Lecture4_interfaces_abstract_classes/WithdrawalTransaction.class b/src/Lecture4_interfaces_abstract_classes/WithdrawalTransaction.class
new file mode 100644
index 0000000000000000000000000000000000000000..6c39558bbb504368cfd6e5e2b3e29599e3ef7e18
GIT binary patch
literal 1412
zcmaJ>-EI>{7(J6XS$ngILr4grg_<;glRyk@X$z*Lu|puOO)Dj81zb(mldyO_yV@Ox
z<`wz^t<(qLrZ@D$NK|U?`%o2UY=@f0LMzSAe81<+_kHuvzpwuS@C6>a$m0VSAL6`=
zDO|9-k8&vB;tchdTwKN#2gNLwU1YIhmsM+Xbp`^L9IQDg35?$fbYSiZtQ0qE&*Y&j
zwM`I~sxnl%A(L`X7D|0k+A&F>56a6w2xO{JLkZ+-fmRROtv!|O%Ds@1F&W3<k-&7Z
zR*|~7;rmfro378~j*)(|F5|wblc+<Lq;&ef@nZpZCu%3Y+6rvYb3X>=X(N%(Ww@J2
zol4&XkzTWCJxt@2gX<n{;1ds@+T}Ccbnv;yEBcbLD^X-plgPNP%+sim=Erd>i`yQ`
zxZ~g}4|lQ76x%v&@9zhGptRX)>qdI-Ctt-jkHF%fvaoNph5aZgJbw#o&Ei=1@HI9(
zRB$tks=(Y(*u1rhOw|Apfr){;BKHGjDw0?3lly3Kc~c-q(MHQ&r9k#LEz3~cwAGmI
z)~#2gqtvJt-J&*4=X%u(qSE&)onZl$Y?WPX;+}wa3{T%K2!Z*QY^rLceQB(MyVOW+
zQbu8xlWibyx|{ah-~vu;Q-!>?x#CGL3)k|it2C7d<TqO!8rx~8I7$O@ICBhBhJ}8|
zGzi$imM!5o0!#m~5A<QwRQ*QnaoJ+CM9GnZ8hgDKMa_0h>f2hYq#DXJRV4W9Akcn{
zUbj4ux)G{$spmLk7zP-=<G6bit0Cr32JFAvd!~Gj#(=0Fg2NZ?1V)t|)H$jr_zlA*
zaN+%SxX4E$&zAuh<paR6;o5yEFvbtatz5abka-31k_T3otBVn?V|+QrDVfDw-{ogy
z7z9{f?O<f3gVA4p!}(Ra=^*n5#_aAjeb9mP0+W9t`)DTj3hv)8Fjc4iY6lZky<|Ax
zI;S?vL^k0fcfbTZezTb56PBm`G%ZeXtY<i@vp7SG95R=46$e?DA?9(mkLwmuS;Px{
zEZ$ozlU*#C->K|To9YsnXTGxxu)xy-bt5>3ZT@Z8`}h_QC|%@vikgopTk5XY-T<ix
BUFQG*

literal 0
HcmV?d00001

diff --git a/src/Lecture4_interfaces_abstract_classes/WithdrawalTransaction.java b/src/Lecture4_interfaces_abstract_classes/WithdrawalTransaction.java
index face5b6..8ddfbea 100644
--- a/src/Lecture4_interfaces_abstract_classes/WithdrawalTransaction.java
+++ b/src/Lecture4_interfaces_abstract_classes/WithdrawalTransaction.java
@@ -1,45 +1,28 @@
 package Lecture4_interfaces_abstract_classes;
-
-import org.jetbrains.annotations.NotNull;
-
 import java.util.Calendar;
 
 public class WithdrawalTransaction extends BaseTransaction {
-    public WithdrawalTransaction(int amount, @NotNull Calendar date) {
-        super(amount, date);
+    public WithdrawalTransaction(double amount, Calendar date, String transactionID) {
+        super(amount, date, transactionID);
     }
 
-    private boolean checkDepositAmount(int amt) {
-        if (amt < 0) {
-            return false;
-        } else {
-            return true;
+    @Override
+    public void apply(BankAccount ba) {
+        try {
+            if (ba.getBalance() >= getAmount()) {
+                ba.withdraw(getAmount());
+                System.out.println("Withdrawn: " + getAmount());
+            } else {
+                throw new InsufficientFundsException("Insufficient funds for withdrawal.");
+            }
+        } catch (InsufficientFundsException e) {
+            System.out.println(e.getMessage());
         }
     }
 
-    // Method to reverse the transaction
-    public boolean reverse() {
+    public boolean reverse(BankAccount ba) {
+        ba.deposit(getAmount());
+        System.out.println("Withdrawal reversed: " + getAmount());
         return true;
-    } // return true if reversal was successful
-
-    // Method to print a transaction receipt or details
-    public void printTransactionDetails() {
-        System.out.println("Deposit Trasaction: " + this.toString());
-    }
-
-    /*
-    Oportunity for assignment: implementing different form of withdrawal
-     */
-    public void apply(BankAccount ba) {
-        double curr_balance = ba.getBalance();
-        if (curr_balance > getAmount()) {
-            double new_balance = curr_balance - getAmount();
-            ba.setBalance(new_balance);
-        }
     }
-
-    /*
-    Assignment 1 Q3: Write the Reverse method - a method unique to the WithdrawalTransaction Class
-     */
 }
-
diff --git a/src/Main.java b/src/Main.java
deleted file mode 100644
index 584a048..0000000
--- a/src/Main.java
+++ /dev/null
@@ -1,156 +0,0 @@
-import Lecture1_adt.*; // Import all classes from Lecture1_adt package to be used in this client code
-
-import java.util.Calendar;
-import java.util.GregorianCalendar;
-import java.util.ArrayList;
-import java.util.List;
-
-//TIP To <b>Run</b> code, press <shortcut actionId="Run"/> or
-// click the <icon src="AllIcons.Actions.Execute"/> icon in the gutter.
-/*
-* Client Code for accessing the Lecture1_adt.TransactionInterface.java module
- */
-public class Main {
-
-    public static void testTransaction1() {
-        Calendar d1 = new GregorianCalendar(); // d1 is an Object [Objects are Reference types]
-        Lecture1_adt.Transaction1 t1 = new Lecture1_adt.Transaction1(1000, d1); // amount and d1 are arguments
-
-        System.out.println(t1.toString());
-        System.out.println("Lecture1_adt.TransactionInterface Amount: \t " + t1.amount);
-        System.out.println("Lecture1_adt.TransactionInterface Date: \t " + t1.date);
-
-        // Please note that the Client Codes can access the data in the class directly through the dot operator
-        // This kind of exposure is a threat to both the Representation Independence and Preservation of Invariants
-    }
-
-
-    /** @return a transaction of same amount as t, one month later
-     * This is a PRODUCER of the class Lecture1_adt.Transaction2
-     * This code will help demostrate the Design exposures still present in transaction2 class
-     * */
-
-    public static Transaction2 makeNextPayment(Transaction2 t) {
-        Calendar d =  t.getDate();
-        d.add(Calendar.MONTH, 1);
-        return new Transaction2(t.getAmount(), d);
-    }
-
-    /*
-    Testing Transaction2 class
-     */
-    public static void testTransaction2() {
-
-        Calendar d1 = new GregorianCalendar();
-
-        Lecture1_adt.Transaction2 t = new Lecture1_adt.Transaction2(1000, d1);
-
-        Lecture1_adt.Transaction2 modified_t = makeNextPayment(t);
-
-        System.out.println("\n\nState of the Object T1 After Client Code Tried to Change the Amount");
-        System.out.println("Lecture1_adt.TransactionInterface Amount: \t "+modified_t.getAmount());
-        System.out.println("Lecture1_adt.TransactionInterface Date: \t "+modified_t.getDate().getTime());
-
-        System.out.println("\n\nHow does T2 Look Like?????");
-        System.out.println("Lecture1_adt.TransactionInterface Amount: \t "+modified_t.getAmount());
-        System.out.println("Lecture1_adt.TransactionInterface Date: \t "+modified_t.getDate().getTime());
-
-        /* Please note that Although we have solved the problem of Transaction1
-        * And client code can no longer use the dot (.) operator to directly access the data
-        * There is still some exposure especially if we pass an object of a previous Transaction2 to create a new Transaction2 object
-         */
-
-    }
-
-
-    /** @return a list of 12 monthly payments of identical amounts
-     * This code will help demostrate the Design exposures still present in transaction3 class
-     * */
-    public static List<Transaction3> makeYearOfPayments (int amount) throws NullPointerException {
-
-        List<Transaction3> listOfTransaction3s = new ArrayList<Transaction3>();
-        Calendar date = new GregorianCalendar(2024, Calendar.JANUARY, 3);
-
-
-        for (int i = 0; i < 12; i++) {
-            listOfTransaction3s.add(new Transaction3(amount, date));
-            date.add(Calendar.MONTH, 1);
-        }
-        return listOfTransaction3s;
-    }
-
-    /*
-    Testing Transaction3 class
-     */
-    public static void testTransaction3() {
-
-        List<Transaction3> allPaymentsIn2024 = makeYearOfPayments(1000);
-
-        for (Transaction3 t3 : allPaymentsIn2024) {
-
-            // Display all the 12 Transactions
-            for (Transaction3 transact : allPaymentsIn2024) {
-                System.out.println("\n\n  ::::::::::::::::::::::::::::::::::::::::::::\n");
-                System.out.println("Lecture1_adt.TransactionInterface Amount: \t "+transact.getAmount());
-                System.out.println("Lecture1_adt.TransactionInterface Date: \t "+transact.getDate().getTime());
-            }
-        }
-
-        /* Please Check all the 12 transactions displayed and hwo their dates look like
-         * Note that Although Transaction3 class resolves to an extent the exposure in Transaction2 class
-         * There is still some exposure especially if we pass an object of a previous Transaction3 to create a
-         * new Transaction3 object
-         */
-    }
-
-
-    /** @return a list of 12 monthly payments of identical amounts
-     * This code Show that by judicious copying and defensive programming we eliminate the exposure in Transaction3
-     * As defined in the constructor of Transaction4 class
-     * */
-
-    public static List<Transaction4> makeYearOfPaymentsFinal (int amount) throws NullPointerException {
-
-        List<Transaction4> listOfTransaction4s = new ArrayList<Transaction4>();
-        Calendar date = new GregorianCalendar(2024, Calendar.JANUARY, 3);
-
-
-        for (int i = 0; i < 12; i++) {
-            listOfTransaction4s.add(new Transaction4(amount, date));
-            date.add(Calendar.MONTH, 1);
-        }
-        return listOfTransaction4s;
-    }
-
-    /*
-    Testing Transaction3 class
-     */
-    public static void testTransaction4() {
-
-        /*
-         * Call the function to make all the Twelve transaction in a year of our business
-         */
-
-        List<Transaction4> transactionsIn2024 = makeYearOfPaymentsFinal(1200);
-
-        // Display all the 12 Transactions
-        for (Transaction4 transact : transactionsIn2024) {
-            System.out.println("\n\n  ::::::::::::::::::::::::::::::::::::::::::::\n");
-            System.out.println("Lecture1_adt.TransactionInterface Amount: \t "+transact.getAmount());
-            System.out.println("Lecture1_adt.TransactionInterface Date: \t "+transact.getDate().getTime());
-        }
-
-        // Please Take a look at all the 12 transaction now and compare with the outputs of the Transaction3 class
-    }
-
-
-    public static void main(String[] args) {
-        // This is the client code
-        // Uncomment the following lines to test the class which you would like to test
-
-        // testTransaction1()
-        // testTransaction2()
-        // testTransaction3()
-        // testTransaction4()
-    }
-}
\ No newline at end of file

From ee24f3f3a7d3c34cf24114ef1a0cdaf536a2839d Mon Sep 17 00:00:00 2001
From: Dangoo2002 <kennydangote893@gmail.com>
Date: Sat, 30 Nov 2024 21:48:28 +0300
Subject: [PATCH 2/4] Assignment Feedback

---
 src/Lecture4_interfaces_abstract_classes/Main.java | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Lecture4_interfaces_abstract_classes/Main.java b/src/Lecture4_interfaces_abstract_classes/Main.java
index 3bb0cad..75fc4b5 100644
--- a/src/Lecture4_interfaces_abstract_classes/Main.java
+++ b/src/Lecture4_interfaces_abstract_classes/Main.java
@@ -10,7 +10,7 @@ public static void main(String[] args) {
         deposit.printTransactionDetails();
         deposit.apply(account);
 
-        System.out.println("Account balance after deposit: " + account.getBalance());
+        System.out.println("Account balance after amount being deposit: " + account.getBalance());
 
         WithdrawalTransaction withdrawal = new WithdrawalTransaction(200, Calendar.getInstance(), "TX002");
         withdrawal.printTransactionDetails();

From 57634236b6163fcff2095e30af0671853b1693ef Mon Sep 17 00:00:00 2001
From: Dangoo2002 <kennydangote893@gmail.com>
Date: Sat, 30 Nov 2024 22:04:37 +0300
Subject: [PATCH 3/4] assignment feedback

---
 src/Lecture4_interfaces_abstract_classes/Main.java | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Lecture4_interfaces_abstract_classes/Main.java b/src/Lecture4_interfaces_abstract_classes/Main.java
index 75fc4b5..8518342 100644
--- a/src/Lecture4_interfaces_abstract_classes/Main.java
+++ b/src/Lecture4_interfaces_abstract_classes/Main.java
@@ -16,7 +16,7 @@ public static void main(String[] args) {
         withdrawal.printTransactionDetails();
         withdrawal.apply(account);
 
-        System.out.println("Account balance after withdrawal: " + account.getBalance());
+        System.out.println("Account balance after withdrawing: " + account.getBalance());
 
         if (withdrawal.reverse(account)) {
             System.out.println("Account balance after reversal: " + account.getBalance());

From c2ec29c131a83b2842473c871c4a33323c24826d Mon Sep 17 00:00:00 2001
From: Dangoo2002 <kennydangote893@gmail.com>
Date: Thu, 5 Dec 2024 11:31:25 +0300
Subject: [PATCH 4/4] Implemented deposit and withdrawal logic, added
 .gitignore

---
 .gitignore                                    |   5 +++-
 .../BankAccount.class                         | Bin 475 -> 701 bytes
 .../BankAccount.java                          |   3 +++
 .../BaseTransaction.class                     | Bin 1776 -> 1847 bytes
 .../BaseTransaction.java                      |  10 +++++---
 .../DepositTransaction.class                  | Bin 997 -> 1475 bytes
 .../DepositTransaction.java                   |  13 ++++++++++
 .../InsufficientFundsException.class          | Bin 252 -> 289 bytes
 .../Main.class                                | Bin 1597 -> 2259 bytes
 .../Main.java                                 |  24 ++++++++++++++----
 .../TransactionInterface.class                | Bin 315 -> 463 bytes
 .../TransactionInterface.java                 |   4 ++-
 .../WithdrawalTransaction.class               | Bin 1412 -> 1468 bytes
 .../WithdrawalTransaction.java                |  16 +++++-------
 14 files changed, 55 insertions(+), 20 deletions(-)

diff --git a/.gitignore b/.gitignore
index f68d109..985ff6c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -26,4 +26,7 @@ bin/
 .vscode/
 
 ### Mac OS ###
-.DS_Store
\ No newline at end of file
+.DS_Store
+
+# Ignore all .class files
+*.class
diff --git a/src/Lecture4_interfaces_abstract_classes/BankAccount.class b/src/Lecture4_interfaces_abstract_classes/BankAccount.class
index 14c015ec3771a88bc9435bae84e65468be3de528..22eca184dd56c75e64cfe5f12207d161fcd3665f 100644
GIT binary patch
literal 701
zcmZvZU279T6o%i~d`z-Q+q7w8{b-wNCCOeiUI<=P1Zxq5RE0>PS7CNCNvGY+hTU0<
zzr+iFfS0290bck6{88fBZ4xTT!0hZf=Xu|AW`6(q`3t}!+;_pTQAQDsGHzhAgqtpI
z;Woz|jx7f6i$EBu7}ya*@v%1AK4HkWk2)vxc@_>SwbIi@y-X&)irxr6polwG_Ha(-
z+8tu~P));FTZYo5wr9ggTrw>6t&kVTVmjygVG>F8T&E(nLt!qSN*N}`?w^adq6!z=
zRg_TX*r}q4U533ECQe2pEwwVXIqSAL3Zv%SMFjgCcdNLEJ%$H8C2bO^hXZY_ibg`J
zcp&`PMnc+w3`88OxO>f*+DNUtbPMC|EB~Bu2AYVbzn18~i>;baB1|Z~(aR7Wc3($i
z)3=cllLLnOf5LPz)3his#I>)$%!?>(#s{4f?9%ISdMySgot;j3I=iUQUZp<|Ia+}0
z{Q&b?-{5@Cs+VYA&N4+JIFThHma#J9wn&drO~LyL=hFfyX2Ddvwy<cSkO@`1Q>tyr
ze>_~$0jatKFsv@1;~BJ*>bKs1K<$bi6a5jDFUYOszoU>g>mY4*joJk2)aW`Iw6?KH
Pv2<Lg!AZKFRj&U9i*|{l

delta 263
zcmXYrNeaS16h!NH659+88B}mY5CQ?$uH1VC_k!mMS-9{JBIriY1LO+cMXVoPbazqz
zRsDW?Z)aS89xnhJi~_hwd^kugGK)c(m!ZWlf`^tMtQNAGW68NoUSQOxa;Yuay#1<{
z$u6MRC8ZOWj8BSjL`u+|F)4h#;s$e}5NJdp5D;|!Wot7%=p<kObOY83PqT{7mgTx8
l)1v%zMyJ@TI^JQf^i9+I`%28_1SvA~IB_5;tNINTe*v606w3er

diff --git a/src/Lecture4_interfaces_abstract_classes/BankAccount.java b/src/Lecture4_interfaces_abstract_classes/BankAccount.java
index 37b8bf4..e5e676e 100644
--- a/src/Lecture4_interfaces_abstract_classes/BankAccount.java
+++ b/src/Lecture4_interfaces_abstract_classes/BankAccount.java
@@ -1,4 +1,5 @@
 package Lecture4_interfaces_abstract_classes;
+
 public class BankAccount {
     private double balance;
 
@@ -17,6 +18,8 @@ public void deposit(double amount) {
     public void withdraw(double amount) {
         if (balance >= amount) {
             balance -= amount;
+        } else {
+            System.out.println("Insufficient balance for withdrawal.");
         }
     }
 }
diff --git a/src/Lecture4_interfaces_abstract_classes/BaseTransaction.class b/src/Lecture4_interfaces_abstract_classes/BaseTransaction.class
index b6d95202b4945c187a94874680d08fa66fd21775..a38098636a75e2d4ebc4995d1a46aa750856d234 100644
GIT binary patch
delta 666
zcmbVJNlqg{5R7VXa$_6l0kbd0#=~N;0ka7Sgwf228>`@86+MN-U>T{q&6NjmLFzMa
z00aVw1Df-Eflu%PL{!6x6XFt)l^GeC%6dsYq$>YkAD;lsW6wkiBXJ}#Y9frW7{>LZ
zpkX48Nfa&WW=xbZYe8UMs}?L6H@{}Y+3d*ry0X27qsrBzx~H5&X)CuX4_wcYwpX=l
z(sh+vtjPNDs%@V%>fX}mwm{5Lr^<1az_%Rs1k8<-hT~s|fkGOY1X|FVz%o_@tiSS9
z78~ACt+*y@s{Thh30U}%KpWcqXYo5<{?f|+p^?ikeo1<JZd@9raE2#K@kGrCaUeJ1
z;VeBmU`{8;SWlya*y-;^3TIu+r4b?OyEY*Xy=M~Lfm1hnw35|67>t0(*d2^31_HV@
z8YK0<^iuLJ&62gWiPFeDLjMrH{?wr7_hSHJ;=}yCLz_oGYkR33M26Vum!g$@J=Wr`
xV6GWM^vR-xTv#y90^}TqSq&jiH1HE!WRv|H*uf^(F7e&Q`V@210nP=u_y((lcd-Bf

delta 524
zcmYk1O)mpc6o%iq^kYV~HQJ(zX=&@Ds=kSYv<WK<iLb<Nw3D<^9qF`|{>1Dgeu0G)
zA+fNq^j{=4w&I<!AU8SZp7TEUp7%TlKYO>|zh7Pftl~sL2w53HOe*Ncln>KRG2?`s
zj9KJWatjI;v7|!6ibJic5LowjN{doocyhO-H_nRXve|C5Hl~j34=LjxKq`PfsP?c(
z`1=tFAc~m1C3d!pCEYT#R#R_Sdbw3I8=8J`QLh=5ytdyyE!TC+GAzxin(cZ;GcS#1
zvsNKrty$W+(W;u2yo8W_D<-7K!<V=b1te)TL~CJmL3M`GunG=!Gv_jUsSjX~amar2
z<o4q1#o%G|b03*UA>V^I0%V4fa7d~nTvTHAOg}>0@gfoV{SF)`5g2t)d()eU{wY!R
z#-O>1>5ctU;_M}na+Pau>B@Pd(gMhb_+pf5!PUnx;ZRi4G$EMfd-&AeC&(QZzeW^S
j$Z(4+w@<S#kij9dLSi4sIN%p^tRvJ5?9IDz*^O&IqNYT)

diff --git a/src/Lecture4_interfaces_abstract_classes/BaseTransaction.java b/src/Lecture4_interfaces_abstract_classes/BaseTransaction.java
index f59feee..4f775e4 100644
--- a/src/Lecture4_interfaces_abstract_classes/BaseTransaction.java
+++ b/src/Lecture4_interfaces_abstract_classes/BaseTransaction.java
@@ -1,7 +1,8 @@
 package Lecture4_interfaces_abstract_classes;
+
 import java.util.Calendar;
 
-public class BaseTransaction implements TransactionInterface {
+public abstract class BaseTransaction implements TransactionInterface {
     private final double amount;
     private final Calendar date;
     private final String transactionID;
@@ -35,7 +36,8 @@ public void printTransactionDetails() {
     }
 
     @Override
-    public void apply(BankAccount ba) {
-        System.out.println("Base transaction applied. Subclasses should override this method.");
-    }
+    public abstract void apply(BankAccount ba);
+
+    @Override
+    public abstract boolean reverse(BankAccount ba);
 }
diff --git a/src/Lecture4_interfaces_abstract_classes/DepositTransaction.class b/src/Lecture4_interfaces_abstract_classes/DepositTransaction.class
index 0d320fb16efe62de99f4b178cd7df7f004506be7..d4bc182a77065ae14ccd2c5decdc0b122706af51 100644
GIT binary patch
literal 1475
zcmbVM?M@Rx6g>l_Th<kj5BU(W2uJ~;s31!5gBFP<MNL3W^aq)42UxnDZFZ*+o<tL0
zfj{~K6MpyrK9up!?g}LkL(C?#^L5WX=gyh=_51iIfCa3Yu+V4X3i?e9;6^J3akG<_
zhE3eYh@KnO%~&TGhEo_fkTEd9kX&-4qn<KMW>$*3e2-`A%5k#=?h0AvelD7Gx!lgK
zE8mgZxrz4-iGo)a4DCfnir4jON%$MQ<kCzFuhrZGhWSjfC~Q^t#oVSNmGHN?ErLy6
z3Y5=nwQ0LN2t<(0b6HuoZLcm>2yFObPxt{L{TISVhO6s}+m$t5iy4{gUfs9Fs-x-k
zu85i!IBLV^G9Vs~Cug*13s=!*VG>gY?pm0}jDf6$S=?jj$a|jBv}<cZ?Re#&J&F4%
zJg_i_c>@nED*q!3k1=Io5i=>|7-ru|U5~W#(y^d)Im*14c4ScB+H!11NR=*eDy=PM
z7#1#7uk-vF<}MYP=YeRD&Ct3n)N)l<o}oE2u|ljb33PH~3`Q)AERk8!&gcj|6#3;K
zP@+oUUY%0(L{4(N>|3&tA~OkI&6!xj69y~RCCZCwM#og;6;be{&D94-?NBdJT&jRj
zD9d?EGIWJ$&w>-Xnoi|P9d|xT(>19G`REK7Qu~yw?DKuXiwXTbKF!O(Q+?)nhS5`z
zj@<JqBEB0D<yA74=N}lLk|v9uSE<)X;VUVHUx;ka@THMYj1k%EC6{Ga1fx;l1^2H(
z$eF;6gPOQt`=^HeZ%Vs#DRYe#j3Ma0yX%e;IRh^k#?I-xh#SMuzxQF7-Xn`1A)uL_
z9lB!Fw$o?~E%X7cljGC<i63C!Xh7bf)<hGv22%7fT!VhEbjTxu&?|jYlSgPeLi2Yd
zbnjRL9U*y&&_+8!X;YN2H%!@u?ii(vM2M1|I)b6YKYztwjF>t>Yz+|;hcwY?5_a<;
z0XBv729TtFC&6pbZj7LZ)b!Ge(MP>d=NRR`9tQMcnf@l_eue^`qaQ;wZX>8$G?xzB
GJAVKc$%;V$

delta 334
zcmW-b%Sr-a6vuzx%;YzYleg?*7t73aH0_>&n{v^rXcx2;3xYr+$Dm!W5Z?pz3@svP
z(I#lodqnGAAUb*u=fMAR{+y54x2}Kvy}bhs_B~uu9-6er1eqw4Or=Gd^_XK`v!Ka6
z9-OC=<>OYndwtmH^akCq8JwBC3R+P-pGB55d7otpniZcStBPc+*9-gMZTsfrGQ8?t
z^b-+EE@hv9il*wbMop16zbc~=rfL;b%!JmdU1!~VTKBGIW9Z#613OTA=E;6>8j7NM
zaB}9(sUB&0d{`C=c|&$gP?0fdh*nCqtn-R`7NGEDdtyaImxwUq#D^#5#|fH4HI6;<
dxDqohew&0~izM44Ua`q8TVzE=G88j1*?({SE9L+I

diff --git a/src/Lecture4_interfaces_abstract_classes/DepositTransaction.java b/src/Lecture4_interfaces_abstract_classes/DepositTransaction.java
index db15e3e..c585717 100644
--- a/src/Lecture4_interfaces_abstract_classes/DepositTransaction.java
+++ b/src/Lecture4_interfaces_abstract_classes/DepositTransaction.java
@@ -1,4 +1,5 @@
 package Lecture4_interfaces_abstract_classes;
+
 import java.util.Calendar;
 
 public class DepositTransaction extends BaseTransaction {
@@ -11,4 +12,16 @@ public void apply(BankAccount ba) {
         ba.deposit(getAmount());
         System.out.println("Deposited: " + getAmount());
     }
+
+    @Override
+    public boolean reverse(BankAccount ba) {
+        if (ba.getBalance() >= getAmount()) {
+            ba.withdraw(getAmount());
+            System.out.println("Deposit reversed: " + getAmount());
+            return true;
+        } else {
+            System.out.println("Unable to reverse deposit: insufficient balance.");
+            return false;
+        }
+    }
 }
diff --git a/src/Lecture4_interfaces_abstract_classes/InsufficientFundsException.class b/src/Lecture4_interfaces_abstract_classes/InsufficientFundsException.class
index c4dddd2fc690bc832531a9bd86c0ef245ed0c60a..67311d291d6ed1029a787346023e36b5f1cde430 100644
GIT binary patch
delta 67
zcmeyvxR7Z=tD3z}YH~?wQL0INW?o5ZQCebhYH@sGQgKO9Vsc4*a!z7#acZ&t#CWNR
V3w-%m7+8Ujk%5DOfq{vE698656pjD@

delta 30
lcmZ3;^oMamE2GrJc&Uj;efgOgSQ%It7#TPi7#NrsI01sm1+4%8

diff --git a/src/Lecture4_interfaces_abstract_classes/Main.class b/src/Lecture4_interfaces_abstract_classes/Main.class
index 4318851c6f99dce5f20d61d4de0adbd3e907efca..6d5faf3bc70f22d24b23dd4cc1eff86e196c79dd 100644
GIT binary patch
literal 2259
zcmbVO%U2s!82?=!nIQxy;nmWX4v%Wm0-?1PB^4=2vDiRsgQcZayqVm<kjYG(2bJT(
zU6;D83zr^OE_4As<s6S|H~JU#_}xi>;gEVbW^w1<@BV(@{hs&cuQ#v%05A<digz%j
z;96wvhdGh}Q8eMYg7+eG-yH~U;HHZAqljR-4Ikh`6*Ez!aZ5@*lEbVdeH<rtMnN_*
zXGleWiaSyCU|Pk3{1UVWvvDwFRNR$|MHQc_xECijiI$`)5-rEkEEPRa@EJqomSGv*
zEJJf5`G}z<V;2QOSI)4+vR^3(XN4C`lC)H~VKMY4p60grHcy${+DPR+$FMfilGu^=
zxL#i3)jB?!w|z$!3x*`OEfINA@?v-w35Kbh&^_M~H`Wcy6HbZi!d>SD*K@e;t?MRt
zUE!wYxmCWc>$Y!slJ}5d`c%BEsM@aKtvK9rNuOa`3i2_m;B$u7mB&+4*QB~f3RYuy
zj3*42qIbR#y6=%QTAi$g*fR>&Vt9&YF?@kU3}0eBhOfXG&dl4kC#|k732)Obx?K?z
zROm4jL4MDi%G_1M+blZ#IX6RR)-AoxFcLEE2ztyu6(xy#D7J;;N+;fei(vzs48x&q
zC*X*p=K4A%!7cfwxiiTyUQ@<Rt;8vZMXl%y&9gPba{W@t&<$aET7gp;=wecZA%l2y
zexo2V3>}CYAF5)DA$h8h$$FybA64T0!WLB&m1!a?t1%wzP(saAhMU4Fa)+UPLwJjp
z>q(PkB`0f@d<>OlxRS^=+Gt$%ArtaDt|uzgNVZRg^wsc&oq9k$;!&pvULoy0fn~?V
z3`$jkO!BEO(fFW&01+yXtner?F4YOIR?QuTn~B`1Vi)SFpmU=XmibyDgIgdQMHwc8
zR&Tw7ENi?(t*RAk%{8MjhJgw%i;QjQ+><3mGZ|fvjOwF2oOFa?w6W6Xhb<83Rq6%u
zKb=~m5^sD?O)octQ<9A_bqBQ&RzXE}^w$hyM<r)i+jd#h@4#9R7U;IIogD=ffk@7_
z%YKz1wrE+x$<*#NhL_<4*LBn`kGtF|n!+8c5z{Bb7m^$!uIyAr19<qRuJuPcoRhi=
z>JKw-cp|NU%J%XJ{~Fmwt^D6O4C6AreDc>s4-(z^G$v_vk-m(+tylKIexnKX8;y~g
z5N)`Mahem9<w@E?d;jdC=}9k|_t2W#M}(%zE40O<duU(!9kF=FE;`3|(KUW`7iUO7
zpYGS7*OKJ>=plTs#P{!EU|HhNl6+zp=Ozd^c!)nA;N|`Wxlel+e?+HT57GJ;w9Dxw
znjSK=L&h+P<>@1J#^_rZV*x{Y-4uAehJKo>Xs3S#=V=^;e3v>X0-f~!cjF#;k*9Zj
z6}@<dK5EOeaB&XbVh}HI0pDW?KT)WE#t42T_A3hdpQPb$3ikwQ?ncWSyim}jAflj0
nNh<X6PX@=QP^E8_LT$l;O-kozJxBq+O|to5{3IB2!Fc~)GiPg!

delta 745
zcmYk4O-~b16o#LfwlnQ?XkqvesI>(_`L=)peo_jGBA@~)_&t_U8?hyAai?9oGG<o(
z0^(8=i^1p*aO=jzjfwGZ5YIG`co*+E_r33Xa_+hJd&3vA@@;STD=>~@aEKnAUM>AP
zEesf_^y&0#>B>K1fWaU`1{%jaNO>?EVuVpoeB2V(guzKp>73TmIj;%?Ib&dX4$E^`
z3|lCk&f;9e65m9Sw9b@H=FPiOB|%aloU!vyr?T0?R=#YKU|PYNaW)I3TzREv=Sz0B
zoGavYW=zg=K_RfRno13O%2|_(Buy?cr*qk4o&}Rdt|-)J3Waj1T(mbAobr>xdMT=L
zHOMuSC6;woOs;c7QE7IE)Obgbn<lHQ1-T{GCFi+QEZG~$M|N(*SszmHySDF@yX^0b
z)c4H)*RA`<H`Zo6cFGxh!_H?N1z%6^jKOX0C?wtOK-~T9A9rK^3Aa6v@`>3k21bH9
zcfCGr_eY>t$-1ic(Z8<H?IyHt_m|c+7nj%ZmMWu@2?=({E-q1#80gzUc`u1Vr=V6N
zeS|nnm*k%Gr?7sBFWp5wRvD;b4)j;4`#?lObeDRl((oB;t%=4@gskQrS{4VZ92gWq
z>%Ok7rt`S=w>0n5u^PQiSQzV|RPwq}Yu$`dCwYJ{Ix+bT2|~}LtuUi<FinJ6qVh})
zGNMMZG_gesFKDG(Y*Exbwsce-O~=ylaimuHC=VnWa=Uvx<UVbjkbRS!j|n$k!?QJ<
F{0nc^c)9=p

diff --git a/src/Lecture4_interfaces_abstract_classes/Main.java b/src/Lecture4_interfaces_abstract_classes/Main.java
index 8518342..3ec0681 100644
--- a/src/Lecture4_interfaces_abstract_classes/Main.java
+++ b/src/Lecture4_interfaces_abstract_classes/Main.java
@@ -1,27 +1,41 @@
 package Lecture4_interfaces_abstract_classes;
-import java.util.Calendar;
 
+import java.util.Calendar;
 
 public class Main {
     public static void main(String[] args) {
+      
         BankAccount account = new BankAccount(1000);
 
         DepositTransaction deposit = new DepositTransaction(500, Calendar.getInstance(), "TX001");
+        System.out.println("\nExecuting Deposit Transaction:");
         deposit.printTransactionDetails();
         deposit.apply(account);
+        System.out.println("Account balance after deposit: " + account.getBalance());
 
-        System.out.println("Account balance after amount being deposit: " + account.getBalance());
 
         WithdrawalTransaction withdrawal = new WithdrawalTransaction(200, Calendar.getInstance(), "TX002");
+        System.out.println("\nExecuting Withdrawal Transaction:");
         withdrawal.printTransactionDetails();
         withdrawal.apply(account);
+        System.out.println("Account balance after withdrawal: " + account.getBalance());
 
-        System.out.println("Account balance after withdrawing: " + account.getBalance());
 
+        System.out.println("\nReversing Withdrawal Transaction:");
         if (withdrawal.reverse(account)) {
-            System.out.println("Account balance after reversal: " + account.getBalance());
+            System.out.println("Withdrawal reversed successfully.");
+        } else {
+            System.out.println("Reversal failed due to insufficient balance.");
+        }
+        System.out.println("Account balance after reversal: " + account.getBalance());
+
+       
+        System.out.println("\nReversing Deposit Transaction:");
+        if (deposit.reverse(account)) {
+            System.out.println("Deposit reversed successfully.");
         } else {
-            System.out.println("Reversal failed.");
+            System.out.println("Reversal failed due to insufficient balance.");
         }
+        System.out.println("Account balance after deposit reversal: " + account.getBalance());
     }
 }
diff --git a/src/Lecture4_interfaces_abstract_classes/TransactionInterface.class b/src/Lecture4_interfaces_abstract_classes/TransactionInterface.class
index 9746b4d690b0b21b0a9d9bf83bbe5612b6f69cd0..d28a0efc6e4cacc368956510ab702b928942ba60 100644
GIT binary patch
delta 227
zcmdnZbe>t@)W2Q(7#JAL8HCvx1lbvcCJH3hvnCc4<Ww>;m}>a=q$Zb?7NwfRXXcfp
z7NsR7rxwR2CKZ<yB_@}|C+8#<7pE5MJ0<32J0>URm*$mNYlbm0uotD4r4|*Zl4$~C
q)Wm$HiEA{~EQzvx;x!{iw#l4~8bU0L47?0{K;JMj@B>LE1_1y_-$^(C

delta 82
zcmX@lyqihj)W2Q(7#JAL83frG_}Li*CJH1@{H!3(npjYfQ_096pyA_`n3wICoSa{p
kS7JSxpHY`lWU?X<modsQvQD1LsKLd+$iNFUf{B3-0Kah)n*aa+

diff --git a/src/Lecture4_interfaces_abstract_classes/TransactionInterface.java b/src/Lecture4_interfaces_abstract_classes/TransactionInterface.java
index 48544cb..a4e591d 100644
--- a/src/Lecture4_interfaces_abstract_classes/TransactionInterface.java
+++ b/src/Lecture4_interfaces_abstract_classes/TransactionInterface.java
@@ -1,10 +1,12 @@
 package Lecture4_interfaces_abstract_classes;
+
 import java.util.Calendar;
 
 public interface TransactionInterface {
     double getAmount();
     Calendar getDate();
     String getTransactionID();
-    void printTransactionDetails();
     void apply(BankAccount ba);
+    boolean reverse(BankAccount ba);
+    void printTransactionDetails();
 }
diff --git a/src/Lecture4_interfaces_abstract_classes/WithdrawalTransaction.class b/src/Lecture4_interfaces_abstract_classes/WithdrawalTransaction.class
index 6c39558bbb504368cfd6e5e2b3e29599e3ef7e18..5e796a02d9fea8abf8132792168655818d929799 100644
GIT binary patch
delta 673
zcma)4O-~a+7=C8Au*>d3v3w%}Qd>$9ic*AD<)ffpiYF7osTs-=nvkySF7e=j3s(<h
zeuW7aP3(afe*ky*310mNhG!Zt-a2pc%*^w?@AJ;gI~VRxck|}&^)CRcc<aE!sDm+#
zJ8<z(uO@o%2$L!LXB?#Q#70Kb*%Sn3EaWWAUGDDZR&v#<Uysj1zgTNDV?R8Sbw8@f
zgD4JVJ+9SHWEA;P;qq&~^VqxcPA~c_<UP#esfPs(izrxF^6(7L1^O#N5bF{jcm4P{
zIE<3rShi90u!0vBRz0ktq)x@`c^L&8F9pgS9doY{A0LMDlRWtl%4WnHG=io;v7_XQ
zjQs!7ma2ZbgSSz)A~0X!wR&fKR=<sO_qx7DMJ3HSv7<`n5AjC*F{=YEyQGK77Vv$D
zN%cN4p6Ms&z#v+%X#x+R+ms|Dk!X7g>PsSX?tVvC%5K5>MwbDdIE*f$N9)BPMYCiV
znLa?4sacCcgBbcJS7LEpXly>;g4se31@-Eh2LN>wS9G#H#6E^<c^f0NQSOHGBn)o0
XI6Dm6z&1AdsixZD2Byh9ZsY7dVl$6l

delta 585
zcmW+z&2G~`7@Uor*s)zFwG-Ng-v-<!p^z3RKP`|FNJ}9`AUIHNtJF0?$c|zcA#vrz
zE!rC|zy%3`M34#saYZ}}k5KV#*3!4TGqdyUj(?bMP5;l~!A}5J@W4O;M-3dqaRW9^
z$koX_PGR05-ZQX(MGZ9_bptvYvYeHgB?k<ihVvSlqm3P<SnG~{H{>K-w#JK?*05}0
z1s5z_l;sjuHC(o+<yD4aJC4&N9rA%6q|f8sq>#fk9cvcWab3d=3pdeXsBA~c{@z}{
z*AJp}b3fWmI<I@dAnnJI7_mjSh?a#7+_KQds*c+XWwFA_WrjkVC&7~;j}qRKat2d8
z%f!kZbj07xo2n58sUIW>4+Dl$t=@gXU-9Nk9)-=v>98M#>!PE0xlMVYdt#u}Sy#MQ
zzA|4tRJ*QCnaQD02J}*@j`*ZjJeM#78LC;zDMxq-Wyuoq4l3z^miVW7;na8NJ5K%^
zj9(vM`(Kb<8p9kz`%H3RnKIMKNE%jY1(>ktD`AR$NP&2l6w?%{LrIlzgcNzG3;DJN
z-5`q@%*wvvQPzEGk$Ynd<$w-@TBsjM%_iRV<VrKtVU~`}(Qb~o3@X^BSsHEOKJF4)
OrM*qeX~ND->bd{zZ(73u

diff --git a/src/Lecture4_interfaces_abstract_classes/WithdrawalTransaction.java b/src/Lecture4_interfaces_abstract_classes/WithdrawalTransaction.java
index 8ddfbea..8c6d5ca 100644
--- a/src/Lecture4_interfaces_abstract_classes/WithdrawalTransaction.java
+++ b/src/Lecture4_interfaces_abstract_classes/WithdrawalTransaction.java
@@ -1,4 +1,5 @@
 package Lecture4_interfaces_abstract_classes;
+
 import java.util.Calendar;
 
 public class WithdrawalTransaction extends BaseTransaction {
@@ -8,18 +9,15 @@ public WithdrawalTransaction(double amount, Calendar date, String transactionID)
 
     @Override
     public void apply(BankAccount ba) {
-        try {
-            if (ba.getBalance() >= getAmount()) {
-                ba.withdraw(getAmount());
-                System.out.println("Withdrawn: " + getAmount());
-            } else {
-                throw new InsufficientFundsException("Insufficient funds for withdrawal.");
-            }
-        } catch (InsufficientFundsException e) {
-            System.out.println(e.getMessage());
+        if (ba.getBalance() >= getAmount()) {
+            ba.withdraw(getAmount());
+            System.out.println("Withdrawn: " + getAmount());
+        } else {
+            System.out.println("Insufficient funds for withdrawal.");
         }
     }
 
+    @Override
     public boolean reverse(BankAccount ba) {
         ba.deposit(getAmount());
         System.out.println("Withdrawal reversed: " + getAmount());