Move articles from spring-core-6 module to other spring-boot modules (#13722)

* Move articles from spring-core-6 module to other spring-boot modules

* JAVA-19559 Move articles from spring-core-6 module to other spring-boot-3 modules

* JAVA-19559 Minor spacing change

* JAVA-19559 Revert  Minor spacing change

spring-boot-modules/spring-boot-3/README.md

@@ -5,3 +5,4 @@
 - [Singleton Design Pattern vs Singleton Beans in Spring Boot](https://www.baeldung.com/spring-boot-singleton-vs-beans)
 - [Migrate Application From Spring Boot 2 to Spring Boot 3](https://www.baeldung.com/spring-boot-3-migration)
 - [Using Java Records with JPA](https://www.baeldung.com/spring-jpa-java-records)
+- [HTTP Interface in Spring 6](https://www.baeldung.com/spring-6-http-interface)

spring-boot-modules/spring-boot-3/pom.xml

@@ -32,6 +32,20 @@
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-data-jpa</artifactId>
         </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-webflux</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.mock-server</groupId>
+            <artifactId>mockserver-netty</artifactId>
+            <version>${mockserver.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.mock-server</groupId>
+            <artifactId>mockserver-client-java</artifactId>
+            <version>${mockserver.version}</version>
+        </dependency>
         <dependency>
             <groupId>com.h2database</groupId>
             <artifactId>h2</artifactId>
@@ -125,7 +139,7 @@
         <springdoc.version>2.0.0</springdoc.version>
         <maven-surefire-plugin.version>3.0.0-M7</maven-surefire-plugin.version>
         <start-class>com.baeldung.sample.TodoApplication</start-class>
-
+		<mockserver.version>5.14.0</mockserver.version>
     </properties>
 
 </project>

spring-boot-modules/spring-boot-3/src/main/java/com/baeldung/httpinterface/Book.java

@@ -0,0 +1,3 @@
+package com.baeldung.httpinterface;
+
+public record Book(long id, String title, String author, int year) {}

spring-boot-modules/spring-boot-3/src/main/java/com/baeldung/httpinterface/BooksClient.java

@@ -0,0 +1,23 @@
+package com.baeldung.httpinterface;
+
+import org.springframework.stereotype.Component;
+import org.springframework.web.reactive.function.client.WebClient;
+import org.springframework.web.reactive.function.client.support.WebClientAdapter;
+import org.springframework.web.service.invoker.HttpServiceProxyFactory;
+
+@Component
+public class BooksClient {
+
+    private final BooksService booksService;
+
+    public BooksClient(WebClient webClient) {
+        HttpServiceProxyFactory httpServiceProxyFactory =
+          HttpServiceProxyFactory.builder(WebClientAdapter.forClient(webClient))
+            .build();
+        booksService = httpServiceProxyFactory.createClient(BooksService.class);
+    }
+
+    public BooksService getBooksService() {
+        return booksService;
+    }
+}

spring-boot-modules/spring-boot-3/src/main/java/com/baeldung/httpinterface/BooksService.java

@@ -0,0 +1,26 @@
+package com.baeldung.httpinterface;
+
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.service.annotation.DeleteExchange;
+import org.springframework.web.service.annotation.GetExchange;
+import org.springframework.web.service.annotation.PostExchange;
+
+import java.util.List;
+
+interface BooksService {
+
+    @GetExchange("/books")
+    List<Book> getBooks();
+
+    @GetExchange("/books/{id}")
+    Book getBook(@PathVariable("id") long id);
+
+    @PostExchange("/books")
+    Book saveBook(@RequestBody Book book);
+
+    @DeleteExchange("/books/{id}")
+    ResponseEntity<Void> deleteBook(@PathVariable("id") long id);
+
+}

spring-boot-modules/spring-boot-3/src/test/java/com/baeldung/httpinterface/MyServiceException.java

@@ -0,0 +1,9 @@
+package com.baeldung.httpinterface;
+
+public class MyServiceException extends RuntimeException {
+
+    MyServiceException(String msg) {
+        super(msg);
+    }
+
+}