fix: monitor pattern is not being built (iluwatar#1956)

* fix: update the version in pom.xml

* fixes the checksyle error and adds javadoc

* fix: bugs and code-smells in sonarcloud

* replaced logger library with Slf4j

* fix tests and add a previously dropped method

* adds license

* fix: codesmells and bug

* replace Random with SecureRandom

* test: add tests for Main to improve coverage

Author: arnabsen1729

monitor/pom.xml

@@ -21,9 +21,9 @@
 <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>
-    <artifactId>java-design-patterns</artifactId>
     <groupId>com.iluwatar</groupId>
-    <version>1.24.0-SNAPSHOT</version>
+    <artifactId>java-design-patterns</artifactId>
+    <version>1.26.0-SNAPSHOT</version>
   </parent>
   <artifactId>monitor</artifactId>
   <dependencies>

monitor/src/main/java/com/iluwatar/monitor/Bank.java

@@ -1,37 +1,87 @@
+/*
+*The MIT License
+*Copyright © 2014-2021 Ilkka Seppälä
+*
+*Permission is hereby granted, free of charge, to any person obtaining a copy
+*of this software and associated documentation files (the "Software"), to deal
+*in the Software without restriction, including without limitation the rights
+*to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+*copies of the Software, and to permit persons to whom the Software is
+*furnished to do so, subject to the following conditions:
+*
+*The above copyright notice and this permission notice shall be included in
+*all copies or substantial portions of the Software.
+*
+*THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+*IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+*FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+*AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+*LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+*OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+*THE SOFTWARE.
+*/
+
 package com.iluwatar.monitor;
 
 import java.util.Arrays;
-import java.util.logging.Logger;
+import lombok.extern.slf4j.Slf4j;
 
-// Bank class implements the Monitor pattern
+/** Bank Definition. */
+@Slf4j
 public class Bank {
 
-    private int[] accounts;
-    Logger logger;
+  private final int[] accounts;
 
-    public Bank(int accountNum, int baseAmount, Logger logger) {
-        this.logger = logger;
-        accounts = new int[accountNum];
-        Arrays.fill(accounts, baseAmount);
-    }
+  /**
+   * Constructor.
+   *
+   * @param accountNum - account number
+   * @param baseAmount - base amount
+   */
+  public Bank(int accountNum, int baseAmount) {
+    accounts = new int[accountNum];
+    Arrays.fill(accounts, baseAmount);
+  }
 
-    public synchronized void transfer(int accountA, int accountB, int amount) {
-        if (accounts[accountA] >= amount) {
-            accounts[accountB] += amount;
-            accounts[accountA] -= amount;
-            logger.info("Transferred from account :" + accountA + " to account :" + accountB + " , amount :" + amount + " . balance :" + getBalance());
-        }
+  /**
+   * Transfer amounts from one account to another.
+   *
+   * @param accountA - source account
+   * @param accountB - destination account
+   * @param amount - amount to be transferred
+   */
+  public synchronized void transfer(int accountA, int accountB, int amount) {
+    if (accounts[accountA] >= amount) {
+      accounts[accountB] += amount;
+      accounts[accountA] -= amount;
+      LOGGER.info(
+          "Transferred from account: {} to account: {} , amount: {} , balance: {}",
+          accountA,
+          accountB,
+          amount,
+          getBalance());
     }
+  }
 
-    public synchronized int getBalance() {
-        int balance = 0;
-        for (int account : accounts) {
-            balance += account;
-        }
-        return balance;
+  /**
+   * Calculates the total balance.
+   *
+   * @return balance
+   */
+  public synchronized int getBalance() {
+    int balance = 0;
+    for (int account : accounts) {
+      balance += account;
     }
+    return balance;
+  }
 
-    public int[] getAccounts() {
-        return accounts;
-    }
+  /**
+   * Get all accounts.
+   *
+   * @return accounts
+   */
+  public int[] getAccounts() {
+    return accounts;
+  }
 }

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

@@ -1,60 +1,73 @@
 /*
- * The MIT License
- * Copyright © 2014-2021 Ilkka Seppälä
+ *The MIT License
+ *Copyright © 2014-2021 Ilkka Seppälä
  *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
+ *Permission is hereby granted, free of charge, to any person obtaining a copy
+ *of this software and associated documentation files (the "Software"), to deal
+ *in the Software without restriction, including without limitation the rights
+ *to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ *copies of the Software, and to permit persons to whom the Software is
+ *furnished to do so, subject to the following conditions:
  *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
+ *The above copyright notice and this permission notice shall be included in
+ *all copies or substantial portions of the Software.
  *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
+ *THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ *IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ *FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ *AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ *LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ *OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ *THE SOFTWARE.
  */
 
 package com.iluwatar.monitor;
 
-import java.util.*;
+import java.security.SecureRandom;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
-import java.util.logging.Logger;
+import lombok.extern.slf4j.Slf4j;
 
 /**
- * <p>The Monitor pattern is used in concurrent algorithms to achieve mutual exclusion.</p>
+ * The Monitor pattern is used in concurrent algorithms to achieve mutual exclusion.
  *
- * <p>Bank is a simple class that transfers money from an account to another account using
- * {@link Bank#transfer}. It can also return the balance of the bank account stored in the bank.</p>
+ * <p>Bank is a simple class that transfers money from an account to another account using {@link
+ * Bank#transfer}. It can also return the balance of the bank account stored in the bank.
  *
- * <p>Main class uses ThreadPool to run threads that do transactions on the bank accounts.</p>
+ * <p>Main class uses ThreadPool to run threads that do transactions on the bank accounts.
  */
-
+@Slf4j
 public class Main {
 
-    public static void main(String[] args) {
-        Logger logger = Logger.getLogger("monitor");
-        var bank = new Bank(4, 1000, logger);
-        Runnable runnable = () -> {
-            try {
-                Thread.sleep((long) (Math.random() * 1000));
-                Random random = new Random();
-                for (int i = 0; i < 1000000; i++)
-                    bank.transfer(random.nextInt(4), random.nextInt(4), (int) (Math.random() * 1000));
-            } catch (InterruptedException e) {
-                logger.info(e.getMessage());
-            }
-        };
-        ExecutorService executorService = Executors.newFixedThreadPool(5);
-        for (int i = 0; i < 5; i++) {
-            executorService.execute(runnable);
-        }
+  /**
+   * Runner to perform a bunch of transfers and handle exception.
+   *
+   * @param bank bank object
+   */
+  public static void runner(Bank bank) {
+    try {
+      SecureRandom random = new SecureRandom();
+      Thread.sleep(random.nextInt(1000));
+      for (int i = 0; i < 1000000; i++) {
+        bank.transfer(random.nextInt(4), random.nextInt(4), random.nextInt());
+      }
+    } catch (InterruptedException e) {
+      LOGGER.info(e.getMessage());
+      Thread.currentThread().interrupt();
+    }
+  }
+
+  /**
+   * Program entry point.
+   *
+   * @param args command line args
+   */
+  public static void main(String[] args) {
+    var bank = new Bank(4, 1000);
+    Runnable runnable = () -> runner(bank);
+    ExecutorService executorService = Executors.newFixedThreadPool(5);
+    for (int i = 0; i < 5; i++) {
+      executorService.execute(runnable);
     }
-}
+  }
+}

monitor/src/main/test/java/com/iluwater/java/BankTest.java

@@ -0,0 +1,71 @@
+/*
+ *The MIT License
+ *Copyright © 2014-2021 Ilkka Seppälä
+ *
+ *Permission is hereby granted, free of charge, to any person obtaining a copy
+ *of this software and associated documentation files (the "Software"), to deal
+ *in the Software without restriction, including without limitation the rights
+ *to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ *copies of the Software, and to permit persons to whom the Software is
+ *furnished to do so, subject to the following conditions:
+ *
+ *The above copyright notice and this permission notice shall be included in
+ *all copies or substantial portions of the Software.
+ *
+ *THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ *IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ *FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ *AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ *LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ *OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ *THE SOFTWARE.
+ */
+
+package com.iluwatar.monitor;
+
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.*;
+import static org.junit.jupiter.api.Assumptions.*;
+
+public class BankTest {
+
+  private static final int ACCOUNT_NUM = 4;
+  private static final int BASE_AMOUNT = 1000;
+  private static Bank bank;
+
+  @BeforeAll
+  public static void Setup() {
+    bank = new Bank(ACCOUNT_NUM, BASE_AMOUNT);
+  }
+
+  @AfterAll
+  public static void TearDown() {
+    bank = null;
+  }
+
+  @Test
+  void GetAccountHaveNotBeNull() {
+    assertNotNull(bank.getAccounts());
+  }
+
+  @Test
+  void LengthOfAccountsHaveToEqualsToAccountNumConstant() {
+    assumeTrue(bank.getAccounts() != null);
+    assertEquals(ACCOUNT_NUM, bank.getAccounts().length);
+  }
+
+  @Test
+  void TransferMethodHaveToTransferAmountFromAnAccountToOtherAccount() {
+    bank.transfer(0, 1, 1000);
+    int[] accounts = bank.getAccounts();
+    assertEquals(0, accounts[0]);
+    assertEquals(2000, accounts[1]);
+  }
+
+  @Test
+  void BalanceHaveToBeOK() {
+    assertEquals(4000, bank.getBalance());
+  }
+}