Implemented FSM design pattern issue #203

Author: Wessam100

FiniteStateMachine/pom.xml

@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <parent>
+        <groupId>com.iluwatar</groupId>
+        <artifactId>java-design-patterns</artifactId>
+        <version>1.26.0-SNAPSHOT</version>
+    </parent>
+
+    <artifactId>FiniteStateMachine</artifactId>
+
+    <properties>
+        <maven.compiler.source>17</maven.compiler.source>
+        <maven.compiler.target>17</maven.compiler.target>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    </properties>
+
+</project>

FiniteStateMachine/src/main/java/com/iluwatar/Main.java

@@ -0,0 +1,59 @@
+public class TrafficLightFSM {
+  // State Interface
+  interface TrafficLightState {
+    void handleEvent(TrafficLightContext context);
+  }
+
+  // Concrete States
+  static class RedLightState implements TrafficLightState {
+    @Override
+    public void handleEvent(TrafficLightContext context) {
+      System.out.println("Red Light: Stop!");
+      context.setState(new GreenLightState());
+    }
+  }
+
+  static class GreenLightState implements TrafficLightState {
+    @Override
+    public void handleEvent(TrafficLightContext context) {
+      System.out.println("Green Light: Go!");
+      context.setState(new YellowLightState());
+    }
+  }
+
+  static class YellowLightState implements TrafficLightState {
+    @Override
+    public void handleEvent(TrafficLightContext context) {
+      System.out.println("Yellow Light: Caution!");
+      context.setState(new RedLightState());
+    }
+  }
+
+  // Context Class
+  static class TrafficLightContext {
+    private TrafficLightState currentState;
+
+    public TrafficLightContext(TrafficLightState initialState) {
+      this.currentState = initialState;
+    }
+
+    public void setState(TrafficLightState newState) {
+      this.currentState = newState;
+    }
+
+    public void handleEvent() {
+      currentState.handleEvent(this);
+    }
+  }
+
+  // Main Method
+  public static void main(String[] args) {
+    // Initialize the traffic light with the Red state
+    TrafficLightContext trafficLight = new TrafficLightContext(new RedLightState());
+
+    // Simulate events
+    for (int i = 0; i < 6; i++) {
+      trafficLight.handleEvent();
+    }
+  }
+}

pom.xml

@@ -218,6 +218,7 @@
     <module>function-composition</module>
     <module>microservices-distributed-tracing</module>
     <module>microservices-idempotent-consumer</module>
+      <module>FiniteStateMachine</module>
   </modules>
   <repositories>
     <repository>