Add SPQR project.

spring-boot-modules/spring-boot-libraries-2/pom.xml

@@ -57,6 +57,11 @@
             <version>${awaitility.version}</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>io.leangen.graphql</groupId>
+            <artifactId>spqr</artifactId>
+            <version>0.11.2</version>
+        </dependency>
     </dependencies>
 
     <build>

spring-boot-modules/spring-boot-libraries-2/src/main/java/com/baeldung/sprq/Book.java

@@ -0,0 +1,57 @@
+package com.baeldung.sprq;
+
+import java.util.Objects;
+
+public class Book {
+    private Integer id;
+    private String author;
+    private String title;
+
+    public Book(Integer id, String author, String title) {
+        this.id = id;
+        this.author = author;
+        this.title = title;
+    }
+
+    public Book() {
+    }
+
+    public Integer getId() {
+        return id;
+    }
+
+    public void setId(Integer id) {
+        this.id = id;
+    }
+
+    public String getAuthor() {
+        return author;
+    }
+
+    public void setAuthor(String author) {
+        this.author = author;
+    }
+
+    public String getTitle() {
+        return title;
+    }
+
+    public void setTitle(String title) {
+        this.title = title;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o)
+            return true;
+        if (o == null || getClass() != o.getClass())
+            return false;
+        Book book = (Book) o;
+        return id.equals(book.id);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(id);
+    }
+}

spring-boot-modules/spring-boot-libraries-2/src/main/java/com/baeldung/sprq/BookResolver.java

@@ -0,0 +1,42 @@
+package com.baeldung.sprq;
+
+import io.leangen.graphql.annotations.GraphQLArgument;
+import io.leangen.graphql.annotations.GraphQLMutation;
+import io.leangen.graphql.annotations.GraphQLQuery;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Profile;
+import org.springframework.stereotype.Service;
+
+import java.util.List;
+
+@Service
+public class BookResolver {
+
+    @Autowired
+    IBookService bookService;
+
+    @GraphQLQuery(name = "getBookWithTitle")
+    public Book getBookWithTitle(@GraphQLArgument(name = "title") String title) {
+        return bookService.getBookWithTitle(title);
+    }
+
+    @GraphQLQuery(name = "getAllBooks", description = "Get all books")
+    public List<Book> getAllBooks() {
+        return bookService.getAllBooks();
+    }
+
+    @GraphQLMutation(name = "addBook")
+    public Book addBook(@GraphQLArgument(name = "newBook") Book book) {
+        return bookService.addBook(book);
+    }
+
+    @GraphQLMutation(name = "updateBook")
+    public Book updateBook(@GraphQLArgument(name = "modifiedBook") Book book) {
+        return bookService.updateBook(book);
+    }
+
+    @GraphQLMutation(name = "deleteBook")
+    public void deleteBook(@GraphQLArgument(name = "book") Book book) {
+        bookService.deleteBook(book);
+    }
+}

spring-boot-modules/spring-boot-libraries-2/src/main/java/com/baeldung/sprq/BookService.java

@@ -0,0 +1,48 @@
+package com.baeldung.sprq;
+
+import org.springframework.context.annotation.Profile;
+import org.springframework.stereotype.Service;
+
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+@Service
+public class BookService implements IBookService {
+
+    Set<Book> books = new HashSet<>();
+
+    @Override
+    public Book getBookWithTitle(String title) {
+        return books.stream()
+            .filter(book -> book.getTitle()
+                .equals(title))
+            .findFirst()
+            .orElse(null);
+    }
+
+    @Override
+    public List<Book> getAllBooks() {
+        return books.stream()
+            .collect(Collectors.toList());
+    }
+
+    @Override
+    public Book addBook(Book book) {
+        books.add(book);
+        return book;
+    }
+
+    @Override
+    public Book updateBook(Book book) {
+        books.remove(book);
+        books.add(book);
+        return book;
+    }
+
+    @Override
+    public boolean deleteBook(Book book) {
+        return books.remove(book);
+    }
+}

spring-boot-modules/spring-boot-libraries-2/src/main/java/com/baeldung/sprq/GraphqlController.java

@@ -0,0 +1,35 @@
+package com.baeldung.sprq;
+
+import graphql.ExecutionResult;
+import graphql.GraphQL;
+import graphql.GraphQLException;
+import graphql.schema.GraphQLSchema;
+import io.leangen.graphql.GraphQLSchemaGenerator;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Profile;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RestController;
+
+import javax.servlet.http.HttpServletRequest;
+import java.util.Map;
+
+@RestController
+public class GraphqlController {
+
+    private final GraphQL graphQL;
+
+    @Autowired
+    public GraphqlController(BookResolver bookResolver) {
+        GraphQLSchema schema = new GraphQLSchemaGenerator().withBasePackages("com.baeldung")
+            .withOperationsFromSingleton(bookResolver)
+            .generate();
+        this.graphQL = new GraphQL.Builder(schema).build();
+    }
+
+    @PostMapping(value = "/graphql")
+    public Map<String, Object> execute(@RequestBody Map<String, String> request, HttpServletRequest raw) throws GraphQLException {
+        ExecutionResult result = graphQL.execute(request.get("query"));
+        return result.getData();
+    }
+}

spring-boot-modules/spring-boot-libraries-2/src/main/java/com/baeldung/sprq/IBookService.java

@@ -0,0 +1,15 @@
+package com.baeldung.sprq;
+
+import java.util.List;
+
+public interface IBookService {
+    Book getBookWithTitle(String title);
+
+    List<Book> getAllBooks();
+
+    Book addBook(Book book);
+
+    Book updateBook(Book book);
+
+    boolean deleteBook(Book book);
+}

spring-boot-modules/spring-boot-libraries-2/src/test/java/com/baeldung/sprq/GraphqlControllerIntegrationTest.java

@@ -0,0 +1,60 @@
+package com.baeldung.sprq;
+
+import org.json.JSONException;
+import org.json.JSONObject;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.http.MediaType;
+import org.springframework.test.context.junit4.SpringRunner;
+import org.springframework.test.web.servlet.MockMvc;
+
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+@RunWith(SpringRunner.class)
+@SpringBootTest
+@AutoConfigureMockMvc
+public class GraphqlControllerIntegrationTest {
+
+    @Autowired
+    private MockMvc mockMvc;
+
+    @Autowired
+    BookService bookService;
+
+    private static final String GRAPHQL_PATH = "/graphql";
+
+    @Test
+    public void givenNoBooks_whenReadAll_thenStatusIsOk() throws Exception {
+
+        String getAllBooksQuery = "{\n" + "  getAllBooks {\n" + "    id\n" + "    author\n" + "    title\n" + "  }\n" + "}\n";
+
+        this.mockMvc.perform(post(GRAPHQL_PATH).content(toJSON(getAllBooksQuery))
+            .contentType(MediaType.APPLICATION_JSON))
+            .andExpect(status().isOk())
+            .andExpect(jsonPath("$.getAllBooks").isEmpty());
+    }
+
+    @Test
+    public void whenAddBook_thenStatusIsOk() throws Exception {
+
+        String addBookMutation = "mutation {\n" + "  addBook(newBook: {id: 123, author: \"J.R.R. Tolkien\", title: \"The Lord of the Rings\"}) {\n" + "    id\n" + "    author\n" + "    title\n" + "  }\n" + "}\n";
+
+        this.mockMvc.perform(post(GRAPHQL_PATH).content(toJSON(addBookMutation))
+            .contentType(MediaType.APPLICATION_JSON))
+            .andExpect(status().isOk())
+            .andExpect(jsonPath("$.addBook.id").value("123"))
+            .andExpect(jsonPath("$.addBook.author").value("J.R.R. Tolkien"))
+            .andExpect(jsonPath("$.addBook.title").value("The Lord of the Rings"));
+    }
+
+    private String toJSON(String query) throws JSONException {
+        JSONObject jsonObject = new JSONObject();
+        jsonObject.put("query", query);
+        return jsonObject.toString();
+    }
+}