diff --git a/build.gradle b/build.gradle
index 545f708..9d06f08 100644
--- a/build.gradle
+++ b/build.gradle
@@ -6,7 +6,7 @@ plugins {
 
 group = 'com.kalyshev'
 version = '0.0.1-SNAPSHOT'
-sourceCompatibility = '1.19'
+sourceCompatibility = '17'
 
 repositories {
 	mavenCentral()
@@ -14,11 +14,20 @@ repositories {
 
 dependencies {
 	implementation 'org.springframework.boot:spring-boot-starter-web'
+	implementation 'org.springframework.boot:spring-boot-starter-thymeleaf'
+	implementation 'org.springframework.boot:spring-boot-devtools'
+	implementation 'nz.net.ultraq.thymeleaf:thymeleaf-layout-dialect'
+
+	implementation 'org.webjars:bootstrap:5.1.3'
+	implementation 'org.webjars:jquery:3.6.0'
+	implementation 'org.webjars:font-awesome:6.1.0'
 
 	implementation 'org.springframework.boot:spring-boot-starter-data-jpa'
 	implementation 'com.h2database:h2:2.1.210'
 
-	implementation group: 'org.springdoc', name: 'springdoc-openapi-ui', version: '1.6.5'
+	implementation 'org.hibernate.validator:hibernate-validator'
+
+	implementation 'org.springdoc:springdoc-openapi-ui:1.6.5'
 
 	testImplementation 'org.springframework.boot:spring-boot-starter-test'
 }
diff --git a/src/main/java/com/kalyshev/yan/cabinet/service/CabinetService.java b/src/main/java/com/kalyshev/yan/cabinet/service/CabinetService.java
index 66d7fcc..09cda43 100644
--- a/src/main/java/com/kalyshev/yan/cabinet/service/CabinetService.java
+++ b/src/main/java/com/kalyshev/yan/cabinet/service/CabinetService.java
@@ -53,7 +53,7 @@ public class CabinetService {
             throw new IllegalArgumentException("Cabinet number is null or empty");
         }
         final Cabinet currentCabinet = findCabinet(id);
-        currentCabinet.setnumber(number);
+        currentCabinet.setNumber(number);
         validatorUtil.validate(currentCabinet);
         return cabinetRepository.save(currentCabinet);
     }
diff --git a/src/main/java/com/kalyshev/yan/computer/service/ComputerService.java b/src/main/java/com/kalyshev/yan/computer/service/ComputerService.java
index 1d9afe2..35079ae 100644
--- a/src/main/java/com/kalyshev/yan/computer/service/ComputerService.java
+++ b/src/main/java/com/kalyshev/yan/computer/service/ComputerService.java
@@ -72,10 +72,10 @@ public class ComputerService {
         }
         final Computer currentComputer = findComputer(id);
         if (modelName != null) {
-            currentComputer.setmodelName(modelName);
+            currentComputer.setModelName(modelName);
         }
         if (serialNum != null) {
-            currentComputer.setserialNum(serialNum);
+            currentComputer.setSerialNum(serialNum);
         }
         if (monitorId != null) {
             Monitor monitor = monitorRepository.findById(monitorId)
diff --git a/src/main/java/com/kalyshev/yan/monitor/service/MonitorService.java b/src/main/java/com/kalyshev/yan/monitor/service/MonitorService.java
index 3f4e5e3..c62c0c9 100644
--- a/src/main/java/com/kalyshev/yan/monitor/service/MonitorService.java
+++ b/src/main/java/com/kalyshev/yan/monitor/service/MonitorService.java
@@ -67,7 +67,9 @@ public class MonitorService {
     public Monitor deleteMonitor(Long id) {
         final Monitor currentMonitor = findMonitor(id);
         Computer computer = getComputer(id);
-        computer.removeMonitor();
+        if (computer != null) {
+            computer.removeMonitor();
+        }
         monitorRepository.delete(currentMonitor);
         return currentMonitor;
     }
@@ -83,8 +85,10 @@ public class MonitorService {
     public Computer getComputer(Long id) {
         List<Computer> computers = computerRepository.findAll();
         for (Computer computer : computers) {
-            if (Objects.equals(computer.getMonitor().getId(), id)) {
-                return computer;
+            if (computer.getMonitor() != null) {
+                if (Objects.equals(computer.getMonitor().getId(), id)) {
+                    return computer;
+                }
             }
         }
         return null;
diff --git a/src/test/java/com/kalyshev/yan/JpaCabinetTests.java b/src/test/java/com/kalyshev/yan/JpaCabinetTests.java
index b3a23ca..4a9dcd2 100644
--- a/src/test/java/com/kalyshev/yan/JpaCabinetTests.java
+++ b/src/test/java/com/kalyshev/yan/JpaCabinetTests.java
@@ -1,10 +1,9 @@
 package com.kalyshev.yan;
 
 import com.kalyshev.yan.cabinet.model.Cabinet;
+import com.kalyshev.yan.cabinet.repository.CabinetNotFoundException;
 import com.kalyshev.yan.cabinet.service.CabinetService;
-import com.kalyshev.yan.computer.model.Computer;
 import com.kalyshev.yan.computer.service.ComputerService;
-import com.kalyshev.yan.monitor.model.Monitor;
 import com.kalyshev.yan.monitor.service.MonitorService;
 import jakarta.persistence.EntityNotFoundException;
 import org.junit.jupiter.api.Assertions;
@@ -45,7 +44,7 @@ public class JpaCabinetTests {
     @Test
     void testCabinetReadNotFound() {
         cabinetService.deleteAllCabinets();
-        Assertions.assertThrows(EntityNotFoundException.class, () -> cabinetService.findCabinet(-1L));
+        Assertions.assertThrows(CabinetNotFoundException.class, () -> cabinetService.findCabinet(-1L));
     }
     @Test
     void testCabinetReadAll() {
diff --git a/src/test/java/com/kalyshev/yan/JpaComputerCabinetTests.java b/src/test/java/com/kalyshev/yan/JpaComputerCabinetTests.java
index 82cf29c..250969c 100644
--- a/src/test/java/com/kalyshev/yan/JpaComputerCabinetTests.java
+++ b/src/test/java/com/kalyshev/yan/JpaComputerCabinetTests.java
@@ -64,7 +64,7 @@ public class JpaComputerCabinetTests {
         computer.setCabinet(cabinet);
         log.info(cabinet.toString());
         log.info(computer.toString());
-        Assertions.assertEquals(computer.getCabinet().getnumber(), cabinet.getnumber());
+        Assertions.assertEquals(computer.getCabinet().getNumber(), cabinet.getNumber());
     }
 
     @Test
@@ -78,7 +78,7 @@ public class JpaComputerCabinetTests {
         computer.setCabinet(cabinet);
         log.info(cabinet.toString());
         log.info(computer.toString());
-        Assertions.assertEquals(computer.getCabinet().getnumber(), cabinet.getnumber());
+        Assertions.assertEquals(computer.getCabinet().getNumber(), cabinet.getNumber());
         computer.setCabinet(null);
         Assertions.assertNull(computer.getCabinet());
     }
diff --git a/src/test/java/com/kalyshev/yan/JpaComputerTests.java b/src/test/java/com/kalyshev/yan/JpaComputerTests.java
index 0060c0e..7e4e0b0 100644
--- a/src/test/java/com/kalyshev/yan/JpaComputerTests.java
+++ b/src/test/java/com/kalyshev/yan/JpaComputerTests.java
@@ -3,6 +3,7 @@ package com.kalyshev.yan;
 import com.kalyshev.yan.cabinet.model.Cabinet;
 import com.kalyshev.yan.cabinet.service.CabinetService;
 import com.kalyshev.yan.computer.model.Computer;
+import com.kalyshev.yan.computer.repository.ComputerNotFoundException;
 import com.kalyshev.yan.computer.service.ComputerService;
 import com.kalyshev.yan.monitor.model.Monitor;
 import com.kalyshev.yan.monitor.service.MonitorService;
@@ -52,7 +53,7 @@ public class JpaComputerTests {
         final Computer computer = computerService.addComputer("Computer", "w7894572", null, null);
         log.info(computer.toString());
         computerService.deleteComputer(computer.getId());
-        Assertions.assertThrows(EntityNotFoundException.class, () -> computerService.findComputer(computer.getId()));
+        Assertions.assertThrows(ComputerNotFoundException.class, () -> computerService.findComputer(computer.getId()));
     }
     @Test
     void testComputerRead() {
@@ -66,7 +67,7 @@ public class JpaComputerTests {
     @Test
     void testComputerReadNotFound() {
         computerService.deleteAllComputers();
-        Assertions.assertThrows(EntityNotFoundException.class, () -> computerService.findComputer(-1L));
+        Assertions.assertThrows(ComputerNotFoundException.class, () -> computerService.findComputer(-1L));
     }
     @Test
     void testComputerReadAll() {
diff --git a/src/test/java/com/kalyshev/yan/JpaMonitorTests.java b/src/test/java/com/kalyshev/yan/JpaMonitorTests.java
index f8f040c..19ce7ce 100644
--- a/src/test/java/com/kalyshev/yan/JpaMonitorTests.java
+++ b/src/test/java/com/kalyshev/yan/JpaMonitorTests.java
@@ -4,6 +4,7 @@ import com.kalyshev.yan.cabinet.service.CabinetService;
 import com.kalyshev.yan.computer.model.Computer;
 import com.kalyshev.yan.computer.service.ComputerService;
 import com.kalyshev.yan.monitor.model.Monitor;
+import com.kalyshev.yan.monitor.repository.MonitorNotFoundException;
 import com.kalyshev.yan.monitor.service.MonitorService;
 import jakarta.persistence.EntityNotFoundException;
 import org.junit.jupiter.api.Assertions;
@@ -44,12 +45,12 @@ public class JpaMonitorTests {
         final Monitor monitor = monitorService.addMonitor("Asus");
         log.info(monitor.toString());
         monitorService.deleteMonitor(monitor.getId());
-        Assertions.assertThrows(EntityNotFoundException.class, () -> monitorService.findMonitor(monitor.getId()));
+        Assertions.assertThrows(MonitorNotFoundException.class, () -> monitorService.findMonitor(monitor.getId()));
     }
     @Test
     void testMonitorReadNotFound() {
         monitorService.deleteAllMonitors();
-        Assertions.assertThrows(EntityNotFoundException.class, () -> monitorService.findMonitor(-1L));
+        Assertions.assertThrows(MonitorNotFoundException.class, () -> monitorService.findMonitor(-1L));
     }
     @Test
     void testMonitorReadAll() {