updated Random() to SecureRandom() (iluwatar#1670)

* updated Random() to SecureRandom()

* batch 2 of SecureRandom updates

Author: ohbus

commander/src/main/java/com/iluwatar/commander/Order.java

@@ -23,8 +23,8 @@
 
 package com.iluwatar.commander;
 
+import java.security.SecureRandom;
 import java.util.Hashtable;
-import java.util.Random;
 
 /**
  * Order class holds details of the order.
@@ -45,7 +45,7 @@ enum MessageSent {
   public final String id;
   final float price;
   final long createdTime;
-  private static final Random RANDOM = new Random();
+  private static final SecureRandom RANDOM = new SecureRandom();
   private static final String ALL_CHARS = "ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
   private static final Hashtable<String, Boolean> USED_IDS = new Hashtable<String, Boolean>();
   PaymentStatus paid;

commander/src/main/java/com/iluwatar/commander/Retry.java

@@ -23,10 +23,10 @@
 
 package com.iluwatar.commander;
 
+import java.security.SecureRandom;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
-import java.util.Random;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.function.Predicate;
 
@@ -56,7 +56,7 @@ public interface HandleErrorIssue<T> {
     void handleIssue(T obj, Exception e);
   }
 
-  private static final Random RANDOM = new Random();
+  private static final SecureRandom RANDOM = new SecureRandom();
 
   private final Operation op;
   private final HandleErrorIssue<T> handleError;

commander/src/main/java/com/iluwatar/commander/Service.java

@@ -24,10 +24,11 @@
 package com.iluwatar.commander;
 
 import com.iluwatar.commander.exceptions.DatabaseUnavailableException;
+
+import java.security.SecureRandom;
 import java.util.ArrayList;
 import java.util.Hashtable;
 import java.util.List;
-import java.util.Random;
 
 /**
  * Service class is an abstract class extended by all services in this example. They all have a
@@ -42,7 +43,7 @@ public abstract class Service {
 
   protected final Database database;
   public ArrayList<Exception> exceptionsList;
-  private static final Random RANDOM = new Random();
+  private static final SecureRandom RANDOM = new SecureRandom();
   private static final String ALL_CHARS = "ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
   private static final Hashtable<String, Boolean> USED_IDS = new Hashtable<>();
 

event-asynchronous/src/main/java/com/iluwatar/event/asynchronous/EventManager.java

@@ -23,8 +23,8 @@
 
 package com.iluwatar.event.asynchronous;
 
+import java.security.SecureRandom;
 import java.util.Map;
-import java.util.Random;
 import java.util.concurrent.ConcurrentHashMap;
 
 /**
@@ -43,7 +43,7 @@ public class EventManager implements ThreadCompleteListener {
   public static final int MAX_ID = MAX_RUNNING_EVENTS;
   public static final int MAX_EVENT_TIME = 1800; // in seconds / 30 minutes.
   private int currentlyRunningSyncEvent = -1;
-  private final Random rand;
+  private final SecureRandom rand;
   private final Map<Integer, Event> eventPool;
 
   private static final String DOES_NOT_EXIST = " does not exist.";
@@ -52,7 +52,7 @@ public class EventManager implements ThreadCompleteListener {
    * EventManager constructor.
    */
   public EventManager() {
-    rand = new Random(1);
+    rand = new SecureRandom();
     eventPool = new ConcurrentHashMap<Integer, Event>(MAX_RUNNING_EVENTS);
 
   }

game-loop/src/main/java/com/iluwatar/gameloop/GameLoop.java

@@ -23,7 +23,7 @@
 
 package com.iluwatar.gameloop;
 
-import java.util.Random;
+import java.security.SecureRandom;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -80,7 +80,7 @@ public boolean isGameRunning() {
    */
   protected void processInput() {
     try {
-      var lag = new Random().nextInt(200) + 50;
+      var lag = new SecureRandom().nextInt(200) + 50;
       Thread.sleep(lag);
     } catch (InterruptedException e) {
       logger.error(e.getMessage());

hexagonal/src/main/java/com/iluwatar/hexagonal/domain/LotteryNumbers.java

@@ -24,10 +24,10 @@
 package com.iluwatar.hexagonal.domain;
 
 import com.google.common.base.Joiner;
+import java.security.SecureRandom;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.PrimitiveIterator;
-import java.util.Random;
 import java.util.Set;
 
 /**
@@ -126,7 +126,7 @@ private static class RandomNumberGenerator {
      * @param max the max value (inclusive)
      */
     public RandomNumberGenerator(int min, int max) {
-      randomIterator = new Random().ints(min, max + 1).iterator();
+      randomIterator = new SecureRandom().ints(min, max + 1).iterator();
     }
 
     /**

hexagonal/src/main/java/com/iluwatar/hexagonal/sampledata/SampleData.java

@@ -30,9 +30,9 @@
 import com.iluwatar.hexagonal.domain.LotteryTicket;
 import com.iluwatar.hexagonal.domain.LotteryTicketId;
 import com.iluwatar.hexagonal.domain.PlayerDetails;
+import java.security.SecureRandom;
 import java.util.AbstractMap.SimpleEntry;
 import java.util.List;
-import java.util.Random;
 import java.util.stream.Collectors;
 
 /**
@@ -41,7 +41,7 @@
 public class SampleData {
 
   private static final List<PlayerDetails> PLAYERS;
-  private static final Random RANDOM = new Random();
+  private static final SecureRandom RANDOM = new SecureRandom();
 
   static {
     PLAYERS = List.of(

leader-followers/src/main/java/com/iluwatar/leaderfollowers/App.java

@@ -23,7 +23,7 @@
 
 package com.iluwatar.leaderfollowers;
 
-import java.util.Random;
+import java.security.SecureRandom;
 import java.util.concurrent.Executors;
 import java.util.concurrent.TimeUnit;
 
@@ -84,7 +84,7 @@ private static void execute(WorkCenter workCenter, TaskSet taskSet) throws Inter
    * Add tasks.
    */
   private static void addTasks(TaskSet taskSet) throws InterruptedException {
-    var rand = new Random();
+    var rand = new SecureRandom();
     for (var i = 0; i < 5; i++) {
       var time = Math.abs(rand.nextInt(1000));
       taskSet.addTask(new Task(time));

master-worker-pattern/src/main/java/com/iluwatar/masterworker/ArrayUtilityMethods.java

@@ -23,7 +23,7 @@
 
 package com.iluwatar.masterworker;
 
-import java.util.Random;
+import java.security.SecureRandom;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -35,7 +35,7 @@ public class ArrayUtilityMethods {
 
   private static final Logger LOGGER = LoggerFactory.getLogger(ArrayUtilityMethods.class);
 
-  private static final Random RANDOM = new Random();
+  private static final SecureRandom RANDOM = new SecureRandom();
 
   /**
    * Method arraysSame compares 2 arrays @param a1 and @param a2 and @return whether their values

producer-consumer/src/main/java/com/iluwatar/producer/consumer/Producer.java

@@ -23,15 +23,15 @@
 
 package com.iluwatar.producer.consumer;
 
-import java.util.Random;
+import java.security.SecureRandom;
 
 /**
  * Class responsible for producing unit of work that can be expressed as {@link Item} and submitted
  * to queue.
  */
 public class Producer {
 
-  private static final Random RANDOM = new Random();
+  private static final SecureRandom RANDOM = new SecureRandom();
 
   private final ItemQueue queue;
 

sharding/src/main/java/com/iluwatar/sharding/LookupShardManager.java

@@ -23,9 +23,9 @@
 
 package com.iluwatar.sharding;
 
+import java.security.SecureRandom;
 import java.util.HashMap;
 import java.util.Map;
-import java.util.Random;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -58,7 +58,7 @@ protected int allocateShard(Data data) {
       return lookupMap.get(key);
     } else {
       var shardCount = shardMap.size();
-      return new Random().nextInt(shardCount - 1) + 1;
+      return new SecureRandom().nextInt(shardCount - 1) + 1;
     }
   }
 

spatial-partition/src/main/java/com/iluwatar/spatialpartition/App.java

@@ -23,8 +23,8 @@
 
 package com.iluwatar.spatialpartition;
 
+import java.security.SecureRandom;
 import java.util.HashMap;
-import java.util.Random;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -112,7 +112,7 @@ static void withSpatialPartition(
   public static void main(String[] args) {
     var bubbles1 = new HashMap<Integer, Bubble>();
     var bubbles2 = new HashMap<Integer, Bubble>();
-    var rand = new Random();
+    var rand = new SecureRandom();
     for (int i = 0; i < 10000; i++) {
       var b = new Bubble(rand.nextInt(300), rand.nextInt(300), i, rand.nextInt(2) + 1);
       bubbles1.put(i, b);

spatial-partition/src/main/java/com/iluwatar/spatialpartition/Bubble.java

@@ -23,9 +23,9 @@
 
 package com.iluwatar.spatialpartition;
 
+import java.security.SecureRandom;
 import java.util.Collection;
 import java.util.HashMap;
-import java.util.Random;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -36,7 +36,7 @@
 
 public class Bubble extends Point<Bubble> {
   private static final Logger LOGGER = LoggerFactory.getLogger(Bubble.class);
-  private static final Random RANDOM = new Random();
+  private static final SecureRandom RANDOM = new SecureRandom();
 
   final int radius;
 

typeobjectpattern/src/main/java/com/iluwatar/typeobject/CellPool.java

@@ -26,9 +26,9 @@
 import com.iluwatar.typeobject.Candy.Type;
 
 import java.io.IOException;
+import java.security.SecureRandom;
 import java.util.ArrayList;
 import java.util.List;
-import java.util.Random;
 import org.json.simple.parser.ParseException;
 
 /**
@@ -38,7 +38,7 @@
  */
 
 public class CellPool {
-  private static final Random RANDOM = new Random();
+  private static final SecureRandom RANDOM = new SecureRandom();
   public static final String FRUIT = "fruit";
   public static final String CANDY = "candy";
   List<Cell> pool;

update-method/src/main/java/com/iluwatar/updatemethod/World.java

@@ -23,9 +23,9 @@
 
 package com.iluwatar.updatemethod;
 
+import java.security.SecureRandom;
 import java.util.ArrayList;
 import java.util.List;
-import java.util.Random;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -66,7 +66,7 @@ private void gameLoop() {
    */
   private void processInput() {
     try {
-      int lag = new Random().nextInt(200) + 50;
+      int lag = new SecureRandom().nextInt(200) + 50;
       Thread.sleep(lag);
     } catch (InterruptedException e) {
       LOGGER.error(e.getMessage());