{"id":145739,"date":"2025-07-04T18:34:26","date_gmt":"2025-07-04T13:04:26","guid":{"rendered":"https:\/\/data-flair.training\/blogs\/?p=145739"},"modified":"2025-07-04T18:34:26","modified_gmt":"2025-07-04T13:04:26","slug":"traffic-light-simulation-using-dsa-java","status":"publish","type":"post","link":"https:\/\/data-flair.training\/blogs\/traffic-light-simulation-using-dsa-java\/","title":{"rendered":"DSA Java Project &#8211; Traffic Light Simulation"},"content":{"rendered":"<h3>Program 1<\/h3>\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\">\/\/ Project: Traffic Light Simulation Using Queue Linked List \r\n\/\/----------------------------------------------------------\r\n\/\/ Features:\r\n\/\/ Add vehicles to queue (simulating arrival)\r\n\/\/ Process vehicles when the signal turns green\r\n\/\/ Show vehicles in the queue\r\n\/\/ Count waiting vehicles\r\n\/\/ Clear All Vehicles (Emergency Clear Signal)\r\n\/\/Search for a Vehicle by Number\r\n\/\/Display First and Last Vehicle in Queue\r\n\/\/Log of Passed Vehicles\r\n\r\nimport java.util.Scanner;\r\n\r\nclass Vehicle    \/\/ Node \r\n{\r\n    String number;\r\n    Vehicle next;\r\n\r\n    Vehicle(String number) \r\n    {\r\n        this.number = number;\r\n        this.next = null;\r\n    }\r\n}\r\n\r\nclass TrafficQueue\r\n {\r\n    private Vehicle front;\r\n    private Vehicle rear;\r\n    private Vehicle passedLog;\r\n\r\n    public TrafficQueue() \r\n    {\r\n        this.front = null;\r\n        this.rear = null;\r\n        this.passedLog = null;\r\n    }\r\n\r\n    public void arriveVehicle(String number) \r\n    {\r\n        Vehicle temp = new Vehicle(number);\r\n        if (rear == null) \r\n        {\r\n            front = rear = temp;\r\n        } else \r\n        {\r\n            rear.next = temp;\r\n            rear = temp;\r\n        }\r\n        System.out.println(\"\\n Vehicle \" + number + \" arrived at the signal.\");\r\n    }\r\n\r\n    private void logPassedVehicle(String number)\r\n     {\r\n        Vehicle temp = new Vehicle(number);\r\n        if (passedLog == null) {\r\n            passedLog = temp;\r\n        } else \r\n        {\r\n            Vehicle ptr = passedLog;\r\n            while (ptr.next != null) \r\n            {\r\n                ptr = ptr.next;\r\n            }\r\n            ptr.next = temp;\r\n        }\r\n    }\r\n\r\n    public void passVehicle() \r\n    {\r\n        if (front == null) \r\n        {\r\n            System.out.println(\"\\n No vehicles waiting at the signal.\");\r\n            return;\r\n        }\r\n        Vehicle temp = front;\r\n        System.out.println(\"\\n--&gt; Vehicle \" + temp.number + \" passed the signal.\");\r\n        logPassedVehicle(temp.number);\r\n        front = front.next;\r\n        temp.next=null;\r\n        temp=null;\r\n        if (front == null)\r\n         rear = null;\r\n    }\r\n\r\n    public void displayQueue() \r\n    {\r\n        if (front == null) \r\n        {\r\n            System.out.println(\"\\n No vehicles in the queue.\");\r\n            return;\r\n        }\r\n        System.out.println(\"\\n Vehicles at signal:\");\r\n        Vehicle temp = front;\r\n        while (temp != null) \r\n        {\r\n            System.out.println(\" --&gt; \" + temp.number);\r\n            temp = temp.next;\r\n        }\r\n    }\r\n\r\n    public void countQueue() \r\n    {\r\n        int count = 0;\r\n        Vehicle temp = front;\r\n        while (temp != null) {\r\n            count++;\r\n            temp = temp.next;\r\n        }\r\n        System.out.println(\"\\n Total vehicles waiting: \" + count);\r\n    }\r\n\r\n    public void clearQueue() \r\n    {\r\n        while (front != null) \r\n        {\r\n            front = front.next;\r\n        }\r\n        rear = null;\r\n        System.out.println(\"\\n All vehicles cleared from the signal!\");\r\n    }\r\n\r\n    public void searchVehicle(String number)\r\n     {\r\n        Vehicle temp = front;\r\n        while (temp != null) \r\n        {\r\n            if (temp.number.equals(number)) \r\n            {\r\n                System.out.println(\"\\n --&gt; Vehicle \" + number + \" is currently in the queue.\");\r\n                return;\r\n            }\r\n            temp = temp.next;\r\n        }\r\n        System.out.println(\"\\n Vehicle \" + number + \" not found in queue.\");\r\n    }\r\n\r\n    public void showFirstAndLast() \r\n    {\r\n        if (front == null) {\r\n            System.out.println(\"\\n No vehicles in the queue.\");\r\n            return;\r\n        }\r\n        System.out.println(\"\\n--&gt; First Vehicle: \" + front.number);\r\n        System.out.println(\" --&gt; Last Vehicle: \" + rear.number);\r\n    }\r\n\r\n    public void showPassedLog() \r\n    {\r\n        if (passedLog == null) {\r\n            System.out.println(\"\\n No vehicles have passed the signal yet.\");\r\n            return;\r\n        }\r\n        System.out.println(\"\\n --&gt; Passed Vehicles Log:\");\r\n        Vehicle temp = passedLog;\r\n        while (temp != null) \r\n        {\r\n            System.out.println(\"   \" + temp.number);\r\n            temp = temp.next;\r\n        }\r\n    }\r\n}\r\n\r\npublic class TrafficSimulation \r\n{\r\n\r\n    public static void main(String[] args) \r\n    {\r\n        Scanner sc = new Scanner(System.in);\r\n        TrafficQueue tq = new TrafficQueue();\r\n        int choice;\r\n        String number;\r\n\r\n        do {\r\n            System.out.println(\"\\n========== Traffic Light Simulation ========== \");\r\n            System.out.println(\"1. Vehicle Arrives\");\r\n            System.out.println(\"2. Signal Turns Green (Vehicle Passes)\");\r\n            System.out.println(\"3. Show Vehicles in Queue\");\r\n            System.out.println(\"4.  Count Waiting Vehicles\");\r\n            System.out.println(\"5. Emergency Clear All Vehicles\");\r\n            System.out.println(\"6. Search Vehicle by Number\");\r\n            System.out.println(\"7. Show First and Last Vehicle\");\r\n            System.out.println(\"8. Show Passed Vehicle Log\");\r\n            System.out.println(\"9. Exit\");\r\n            System.out.println(\"\\n==================================== \");\r\n            System.out.print(\" Choose an option: \");\r\n            choice = Integer.parseInt(sc.nextLine());\r\n\r\n            switch (choice) \r\n            {\r\n                case 1:\r\n                    System.out.print(\" Enter vehicle number: \");\r\n                    number = sc.nextLine();\r\n                    tq.arriveVehicle(number);\r\n                    break;\r\n                case 2:\r\n                    tq.passVehicle();\r\n                    break;\r\n                case 3:\r\n                    tq.displayQueue();\r\n                    break;\r\n                case 4:\r\n                    tq.countQueue();\r\n                    break;\r\n                case 5:\r\n                    tq.clearQueue();\r\n                    break;\r\n                case 6:\r\n                    System.out.print(\" Enter vehicle number to search: \");\r\n                    number = sc.nextLine();\r\n                    tq.searchVehicle(number);\r\n                    break;\r\n                case 7:\r\n                    tq.showFirstAndLast();\r\n                    break;\r\n                case 8:\r\n                    tq.showPassedLog();\r\n                    break;\r\n                case 9:\r\n                    System.out.println(\"\\n Exiting simulation. Goodbye!\");\r\n                    break;\r\n                default:\r\n                    System.out.println(\"\\n Invalid option. Try again.\");\r\n            }\r\n        } while (choice != 9);\r\n\r\n        sc.close();\r\n    }\r\n}<\/pre>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Program 1 \/\/ Project: Traffic Light Simulation Using Queue Linked List \/\/&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8212;- \/\/ Features: \/\/ Add vehicles to queue (simulating arrival) \/\/ Process vehicles when the signal turns green \/\/ Show vehicles in the&#46;&#46;&#46;<\/p>\n","protected":false},"author":581,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[31451],"tags":[32318,34815,34814,32290,32293,34806,34813,34812],"class_list":["post-145739","post","type-post","status-publish","format-standard","hentry","category-dsa-java-tutorials","tag-dsa-java","tag-dsa-java-program-traffic-light-simulation","tag-dsa-java-traffic-light-simulation-project","tag-dsa-using-java","tag-dsa-using-java-program","tag-dsa-using-java-project","tag-traffic-light-simulation","tag-traffic-light-simulation-using-dsa-java"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.8 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>DSA Java Project - Traffic Light Simulation - DataFlair<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/data-flair.training\/blogs\/traffic-light-simulation-using-dsa-java\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"DSA Java Project - Traffic Light Simulation - DataFlair\" \/>\n<meta property=\"og:description\" content=\"Program 1 \/\/ Project: Traffic Light Simulation Using Queue Linked List \/\/---------------------------------------------------------- \/\/ Features: \/\/ Add vehicles to queue (simulating arrival) \/\/ Process vehicles when the signal turns green \/\/ Show vehicles in the&#046;&#046;&#046;\" \/>\n<meta property=\"og:url\" content=\"https:\/\/data-flair.training\/blogs\/traffic-light-simulation-using-dsa-java\/\" \/>\n<meta property=\"og:site_name\" content=\"DataFlair\" \/>\n<meta property=\"article:publisher\" content=\"https:\/\/www.facebook.com\/DataFlairWS\/\" \/>\n<meta property=\"article:published_time\" content=\"2025-07-04T13:04:26+00:00\" \/>\n<meta name=\"author\" content=\"DataFlair Team\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:creator\" content=\"@DataFlairWS\" \/>\n<meta name=\"twitter:site\" content=\"@DataFlairWS\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"DataFlair Team\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"1 minute\" \/>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"DSA Java Project - Traffic Light Simulation - DataFlair","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/data-flair.training\/blogs\/traffic-light-simulation-using-dsa-java\/","og_locale":"en_US","og_type":"article","og_title":"DSA Java Project - Traffic Light Simulation - DataFlair","og_description":"Program 1 \/\/ Project: Traffic Light Simulation Using Queue Linked List \/\/---------------------------------------------------------- \/\/ Features: \/\/ Add vehicles to queue (simulating arrival) \/\/ Process vehicles when the signal turns green \/\/ Show vehicles in the&#46;&#46;&#46;","og_url":"https:\/\/data-flair.training\/blogs\/traffic-light-simulation-using-dsa-java\/","og_site_name":"DataFlair","article_publisher":"https:\/\/www.facebook.com\/DataFlairWS\/","article_published_time":"2025-07-04T13:04:26+00:00","author":"DataFlair Team","twitter_card":"summary_large_image","twitter_creator":"@DataFlairWS","twitter_site":"@DataFlairWS","twitter_misc":{"Written by":"DataFlair Team","Est. reading time":"1 minute"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/data-flair.training\/blogs\/traffic-light-simulation-using-dsa-java\/#article","isPartOf":{"@id":"https:\/\/data-flair.training\/blogs\/traffic-light-simulation-using-dsa-java\/"},"author":{"name":"DataFlair Team","@id":"https:\/\/data-flair.training\/blogs\/#\/schema\/person\/c187795dc82ab948373cca526df7c445"},"headline":"DSA Java Project &#8211; 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