Merge pull request #7310 from veontomo/BAEL-3095

Create an interface driven controller (BAEL-3095)

spring-5-mvc/pom.xml

@@ -3,9 +3,7 @@
     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>
-    <groupId>com.baeldung</groupId>
     <artifactId>spring-5-mvc</artifactId>
-    <version>0.0.1-SNAPSHOT</version>
     <name>spring-5-mvc</name>
     <description>spring 5 MVC sample project about new features</description>
     <packaging>jar</packaging>
@@ -83,6 +81,11 @@
             <version>${jayway-rest-assured.version}</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>com.github.javafaker</groupId>
+            <artifactId>javafaker</artifactId>
+            <version>0.18</version>
+        </dependency>
     </dependencies>
 
     <build>

spring-5-mvc/src/main/java/com/baeldung/idc/Application.java

@@ -0,0 +1,13 @@
+package com.baeldung.idc;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class Application {
+
+    public static void main(String[] args) {
+        SpringApplication.run(Application.class, args);
+    }
+
+}

spring-5-mvc/src/main/java/com/baeldung/idc/Book.java

@@ -0,0 +1,55 @@
+package com.baeldung.idc;
+
+import org.springframework.stereotype.Component;
+
+@Component
+public class Book {
+
+    private final int id;
+
+    private final String title;
+
+    private final String author;
+
+    private final String genre;
+    
+    public Book() {
+        this(-1, "", "", "");
+    }
+
+    public Book(int id, String title, String author, String genre) {
+        this.id = id;
+        this.title = title;
+        this.author = author;
+        this.genre = genre;
+    }
+
+    /**
+     * @return the id
+     */
+    public int getId() {
+        return id;
+    }
+
+    /**
+     * @return the title
+     */
+    public String getTitle() {
+        return title;
+    }
+
+    /**
+     * @return the author
+     */
+    public String getAuthor() {
+        return author;
+    }
+
+    /**
+     * @return the genre
+     */
+    public String getGenre() {
+        return genre;
+    }
+
+}

spring-5-mvc/src/main/java/com/baeldung/idc/BookController.java

@@ -0,0 +1,34 @@
+package com.baeldung.idc;
+
+import java.util.List;
+import java.util.Optional;
+
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+@RequestMapping("/book")
+public class BookController implements BookOperations {
+
+    private BookRepository repo;
+    
+    public BookController(BookRepository repo) {
+        this.repo = repo;
+    }
+
+    @Override
+    public List<Book> getAll() {
+        return repo.getItems();
+    }
+
+    @Override
+    public Optional<Book> getById(int id) {
+        return repo.getById(id);
+    }
+
+    @Override
+    public void save(Book book, int id) {
+        repo.save(id, book);
+    }
+
+}

spring-5-mvc/src/main/java/com/baeldung/idc/BookOperations.java

@@ -0,0 +1,23 @@
+package com.baeldung.idc;
+
+import java.util.List;
+import java.util.Optional;
+
+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.RequestBody;
+import org.springframework.web.bind.annotation.RequestMapping;
+
+@RequestMapping("/default")
+public interface BookOperations {
+
+    @GetMapping("/")
+    List<Book> getAll();
+
+    @GetMapping("/{id}")
+    Optional<Book> getById(@PathVariable int id);
+
+    @PostMapping("/save/{id}")
+    public void save(@RequestBody Book book, @PathVariable int id);
+}

spring-5-mvc/src/main/java/com/baeldung/idc/BookRepository.java

@@ -0,0 +1,61 @@
+package com.baeldung.idc;
+
+import java.util.List;
+import java.util.Locale;
+import java.util.Optional;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+
+import javax.annotation.PostConstruct;
+
+import org.springframework.stereotype.Component;
+
+import com.github.javafaker.Faker;
+
+/**
+ * Repository for storing the books.
+ * 
+ * It serves just for illustrative purposes and is completely in-memory. It uses Java Faker library in order to generate data.
+ * 
+ * @author A.Shcherbakov
+ *
+ */
+@Component
+public class BookRepository {
+
+    private List<Book> items;
+
+    @PostConstruct
+    public void init() {
+        Faker faker = new Faker(Locale.ENGLISH);
+        final com.github.javafaker.Book book = faker.book();
+        this.items = IntStream.range(1, faker.random()
+            .nextInt(10, 20))
+            .mapToObj(i -> new Book(i, book.title(), book.author(), book.genre()))
+            .collect(Collectors.toList());
+
+    }
+
+    public int getCount() {
+        return items.size();
+    }
+
+    public List<Book> getItems() {
+        return items;
+    }
+
+    public Optional<Book> getById(int id) {
+        return this.items.stream()
+            .filter(item -> id == item.getId())
+            .findFirst();
+    }
+
+    public void save(int id, Book book) {
+        IntStream.range(0, items.size())
+            .filter(i -> items.get(i)
+                .getId() == id)
+            .findFirst()
+            .ifPresent(i -> this.items.set(i, book));
+    }
+
+}