Hash set 2

src/com/school/faang/hashset/задача_2/Solution.java

@@ -2,6 +2,15 @@
 
 public class Solution {
     public static void main(String[] args) {
-
+        User firstUser = new User("first");
+        User secondUser = new User("second");
+        User thirdUser = new User("third");
+        firstUser.blockUser(secondUser);
+        secondUser.blockUser(thirdUser);
+        thirdUser.blockUser((User) null);
+        System.out.println(firstUser.amIBlocked());
+        System.out.println(thirdUser.amIBlocked());
+        System.out.println(firstUser.isUserBlocked(secondUser));
+        System.out.println(firstUser.isUserBlocked(thirdUser));
     }
 }

src/com/school/faang/hashset/задача_2/User.java

@@ -0,0 +1,69 @@
+package com.school.faang.hashset.задача_2;
+
+public class User {
+
+    private String username;
+
+    private final UserBlackList userBlackList;
+
+    private boolean isUserBlocked;
+
+    public User(String username) {
+        this.username = username;
+        userBlackList = new UserBlackList();
+        isUserBlocked = false;
+    }
+
+    public String getUsername() {
+        return username;
+    }
+
+    public void blockUser(String username) {
+        if (username == null) {
+            isUserBlocked = true;
+            return;
+        }
+        userBlackList.blockUser(username);
+    }
+
+    public void blockUser(User user) {
+        if (user == null) {
+            isUserBlocked = true;
+            return;
+        }
+        blockUser(user.toString());
+    }
+
+    public void unblockUser(String username) {
+        if (username == null) {
+            isUserBlocked = false;
+            return;
+        }
+        userBlackList.unblockUser(username);
+    }
+
+    public void unblockUser(User user) {
+        if (user == null) {
+            isUserBlocked = false;
+            return;
+        }
+        userBlackList.unblockUser(user.toString());
+    }
+
+    public boolean isUserBlocked(String username) {
+        return userBlackList.isUserBlocked(username);
+    }
+
+    public boolean isUserBlocked(User user) {
+        return isUserBlocked(user.toString());
+    }
+
+    public boolean amIBlocked() {
+        return isUserBlocked;
+    }
+
+    @Override
+    public String toString() {
+        return username;
+    }
+}

src/com/school/faang/hashset/задача_2/UserBlackList.java

@@ -0,0 +1,28 @@
+package com.school.faang.hashset.задача_2;
+
+import java.util.Set;
+import java.util.HashSet;
+
+public class UserBlackList {
+
+    private final Set<String> blackList;
+
+    public UserBlackList() {
+        blackList = new HashSet<>();
+    }
+
+    public void blockUser(String username) {
+        blackList.add(username);
+    }
+
+    public void unblockUser(String username) {
+        if (username == null) {
+            return;
+        }
+        blackList.remove(username);
+    }
+
+    public boolean isUserBlocked(String username) {
+        return blackList.contains(username);
+    }
+}