Modernize Spring Boot 2.7, add validation, exception handling, and tests

.gitignore

@@ -1 +1,63 @@
-/.idea/
+/.idea/
+
+# Compiled class files
+*.class
+
+# Log files
+*.log
+
+# Package files
+*.jar
+*.war
+*.nar
+*.ear
+*.zip
+*.tar.gz
+*.rar
+
+# Maven
+target/
+pom.xml.tag
+pom.xml.releaseBackup
+pom.xml.versionsBackup
+pom.xml.next
+release.properties
+dependency-reduced-pom.xml
+buildNumber.properties
+.mvn/timing.properties
+.mvn/wrapper/maven-wrapper.jar
+
+# Gradle
+build/
+.gradle/
+!gradle/wrapper/gradle-wrapper.jar
+
+# Eclipse
+.classpath
+.project
+.settings/
+bin/
+
+# IntelliJ
+*.iml
+*.iws
+*.ipr
+out/
+
+# NetBeans
+nbproject/private/
+nbbuild/
+dist/
+nbdist/
+.nb-gradle/
+
+# VS Code
+.vscode/
+
+# OS files
+.DS_Store
+Thumbs.db
+
+# Virtual machine crash logs
+hs_err_pid*
+replay_pid*

build.gradle

@@ -3,7 +3,7 @@ buildscript {
         mavenCentral()
     }
     dependencies {
-        classpath("org.springframework.boot:spring-boot-gradle-plugin:2.0.2.RELEASE")
+        classpath("org.springframework.boot:spring-boot-gradle-plugin:2.7.18")
     }
 }
 

pom.xml

@@ -5,13 +5,13 @@
 
     <groupId>org.springframework</groupId>
     <artifactId>gs-spring-boot</artifactId>
-    <packaging>pom</packaging>
+    <packaging>jar</packaging>
     <version>0.1.0</version>
 
     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
-        <version>2.0.2.RELEASE</version>
+        <version>2.7.18</version>
     </parent>
 
     <dependencies>
@@ -28,10 +28,24 @@
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-jdbc</artifactId>
         </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-validation</artifactId>
+        </dependency>
         <dependency>
             <groupId>com.h2database</groupId>
             <artifactId>h2</artifactId>
         </dependency>
+        <dependency>
+            <groupId>org.springdoc</groupId>
+            <artifactId>springdoc-openapi-ui</artifactId>
+            <version>1.7.0</version>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
     <properties>

src/main/java/hello/Application.java

@@ -5,18 +5,14 @@
 import java.util.stream.Collectors;
 
 import hello.model.Customer;
-import hello.model.Quote;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.CommandLineRunner;
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
-import org.springframework.boot.web.client.RestTemplateBuilder;
 import org.springframework.context.ApplicationContext;
-import org.springframework.context.annotation.Bean;
 import org.springframework.jdbc.core.JdbcTemplate;
-import org.springframework.web.client.RestTemplate;
 
 @SpringBootApplication
 public class Application implements CommandLineRunner {
@@ -34,25 +30,6 @@ public static void main(String[] args) {
         for (String beanName : beanNames) {
             System.out.println(beanName);
         }
-
-        RestTemplate restTemplate =  new RestTemplate();
-        Quote quote = restTemplate.getForObject("http://gturnquist-quoters.cfapps.io/api/random", Quote.class);
-        log.info(quote.toString());
-    }
-
-
-    @Bean
-    public RestTemplate restTemplate(RestTemplateBuilder builder) {
-        return builder.build();
-    }
-
-    @Bean
-    public CommandLineRunner run(RestTemplate restTemplate) throws Exception {
-        return args -> {
-            Quote quote = restTemplate.getForObject(
-                    "http://gturnquist-quoters.cfapps.io/api/random", Quote.class);
-            log.info(quote.toString());
-        };
     }
 
 

src/main/java/hello/controller/HelloController.java

@@ -1,23 +1,16 @@
 package hello.controller;
 
+import hello.declaration.SimpleTimeClient;
 import hello.declaration.TimeClient;
-import hello.model.SimpleTimeClient;
-import hello.model.Topic;
 import hello.service.TopicService;
 import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.RestController;
-import org.springframework.web.bind.annotation.RequestMapping;
 
 import java.time.LocalDate;
 import java.time.LocalDateTime;
-import java.time.LocalTime;
 import java.time.ZoneId;
-import java.time.chrono.ChronoPeriod;
 import java.time.temporal.ChronoUnit;
-import java.util.List;
-import java.util.regex.Pattern;
-import java.util.stream.Collector;
-import java.util.stream.Collectors;
 
 @RestController
 public class HelloController {
@@ -43,7 +36,7 @@ public class HelloController {
      *
      * @return
      */
-    @RequestMapping("/datetime")
+    @GetMapping("/datetime")
     public String index() {
         TimeClient myTimeClient = new SimpleTimeClient();
         LocalDateTime localDateTime = LocalDateTime.now();
@@ -63,7 +56,7 @@ public String index() {
      *
      * @return
      */
-    @RequestMapping("/topic/string/operation")
+    @GetMapping("/topic/string/operation")
     public String showStringOperation() {
 
         String join = topicService.returnAllTopicIDWithStringSlicing();
@@ -84,7 +77,7 @@ public String showStringOperation() {
      * File Operation in Java 8
      * @return
      */
-    @RequestMapping("/topic/file/operation")
+    @GetMapping("/topic/file/operation")
     public String showFileOperation() {
         String findAllFilesInPathAndSort = topicService.findAllFilesInPathAndSort();
         String findParticularFileInPathAndSort = topicService.findParticularFileInPathAndSort();

src/main/java/hello/controller/TopicController.java

@@ -3,8 +3,17 @@
 import hello.model.Topic;
 import hello.service.TopicService;
 import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.web.bind.annotation.*;
-
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.DeleteMapping;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.PutMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RestController;
+
+import javax.validation.Valid;
 import java.util.List;
 
 @RestController
@@ -18,68 +27,71 @@ public class TopicController {
      * Get all Topic
      * @return
      */
-    @RequestMapping("/topic")
-    public List<Topic> getAllTopics() {
-        return topicService.getAllTopics();
+    @GetMapping("/topic")
+    public ResponseEntity<List<Topic>> getAllTopics() {
+        return ResponseEntity.ok(topicService.getAllTopics());
     }
 
     /**
      * get Topic with ID
      * @param id
      * @return
      */
-    @RequestMapping("/topic/{id}")
-    public Topic getTopicWithID(@PathVariable String id) {
-        return topicService.getTopicWithId(id);
+    @GetMapping("/topic/{id}")
+    public ResponseEntity<Topic> getTopicWithID(@PathVariable String id) {
+        return ResponseEntity.ok(topicService.getTopicWithId(id));
     }
 
     /**
      * Add a new topic in list
      * @param topic
      */
-    @RequestMapping(method = RequestMethod.POST, value = "/topic")
-    public void addTopic(@RequestBody Topic topic) {
+    @PostMapping("/topic")
+    public ResponseEntity<Void> addTopic(@Valid @RequestBody Topic topic) {
         topicService.addTopic(topic);
+        return ResponseEntity.status(HttpStatus.CREATED).build();
     }
 
     /**
      * Update Topic in List with id
      * @param id
      * @param topic
      */
-    @RequestMapping(method = RequestMethod.PUT, value = "/topic/{id}")
-    public void updateTopic(@PathVariable String id, @RequestBody Topic topic) {
+    @PutMapping("/topic/{id}")
+    public ResponseEntity<Void> updateTopic(@PathVariable String id, @Valid @RequestBody Topic topic) {
         topicService.updateTopic(id, topic);
+        return ResponseEntity.ok().build();
     }
 
 
     /**
      * Delete a topic with ID
      * @param id
      */
-    @RequestMapping(method = RequestMethod.DELETE, value = "/topic/{id}")
-    public void deleteTopic(@PathVariable String id) {
+    @DeleteMapping("/topic/{id}")
+    public ResponseEntity<Void> deleteTopic(@PathVariable String id) {
         topicService.deleteTopic(id);
+        return ResponseEntity.noContent().build();
     }
 
     /**
      * Get all topics with Id length greater then minimum length
      * @param minLength
      * @return
      */
-    @RequestMapping(value = "/topic/minimum/length/{minLength}")
-    public List<Topic> filterMinimumLengthForId(@PathVariable Integer minLength) {
-        return topicService.filterMinimumLengthForId(minLength);
+    @GetMapping("/topic/minimum/length/{minLength}")
+    public ResponseEntity<List<Topic>> filterMinimumLengthForId(@PathVariable Integer minLength) {
+        return ResponseEntity.ok(topicService.filterMinimumLengthForId(minLength));
     }
 
 
     /**
      * Sort with Id
      * @return
      */
-    @RequestMapping("/topic/sort")
-    public List<Topic> sortTopicsWithID() {
-        return topicService.sortTopicsWithID();
+    @GetMapping("/topic/sort")
+    public ResponseEntity<List<Topic>> sortTopicsWithID() {
+        return ResponseEntity.ok(topicService.sortTopicsWithID());
     }
 
 

src/main/java/hello/declaration/CustomPredicate.java

@@ -4,6 +4,7 @@
  * Use as a Functional Interface
  * @param <T>
  */
+@FunctionalInterface
 public  interface  CustomPredicate <T>{
     boolean test(T t);
 }

src/main/java/hello/model/SimpleTimeClient.java → src/main/java/hello/declaration/SimpleTimeClient.java

@@ -1,6 +1,4 @@
-package hello.model;
-
-import hello.declaration.TimeClient;
+package hello.declaration;
 
 import java.time.LocalDate;
 import java.time.LocalDateTime;

src/main/java/hello/exception/GlobalExceptionHandler.java

@@ -0,0 +1,38 @@
+package hello.exception;
+
+import java.time.LocalDateTime;
+import java.util.HashMap;
+import java.util.Map;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.ControllerAdvice;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+
+@ControllerAdvice
+public class GlobalExceptionHandler {
+
+    private static final Logger log = LoggerFactory.getLogger(GlobalExceptionHandler.class);
+
+    @ExceptionHandler(TopicNotFoundException.class)
+    public ResponseEntity<Map<String, Object>> handleTopicNotFound(TopicNotFoundException ex) {
+        return buildResponse(HttpStatus.NOT_FOUND, ex.getMessage());
+    }
+
+    @ExceptionHandler(Exception.class)
+    public ResponseEntity<Map<String, Object>> handleGenericException(Exception ex) {
+        log.error("Unhandled exception", ex);
+        return buildResponse(HttpStatus.INTERNAL_SERVER_ERROR, ex.getMessage());
+    }
+
+    private ResponseEntity<Map<String, Object>> buildResponse(HttpStatus status, String message) {
+        Map<String, Object> body = new HashMap<>();
+        body.put("timestamp", LocalDateTime.now().toString());
+        body.put("status", status.value());
+        body.put("error", status.getReasonPhrase());
+        body.put("message", message);
+        return ResponseEntity.status(status).body(body);
+    }
+}

src/main/java/hello/exception/TopicNotFoundException.java

@@ -0,0 +1,12 @@
+package hello.exception;
+
+public class TopicNotFoundException extends RuntimeException {
+
+    public TopicNotFoundException(String message) {
+        super(message);
+    }
+
+    public TopicNotFoundException(String message, Throwable cause) {
+        super(message, cause);
+    }
+}