BAEL-5304: adding graphql-spqr module

graphql/graphql-spqr/src/main/java/com/baeldung/SpringBootApp.java

@@ -0,0 +1,11 @@
+package com.baeldung;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class SpringBootApp {
+    public static void main(String[] args) {
+        SpringApplication.run(SpringBootApp.class, args);
+    }
+}

graphql/graphql-spqr/src/main/java/com/baeldung/spqr/Book.java

@@ -0,0 +1,57 @@
+package com.baeldung.spqr;
+
+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);
+    }
+}

graphql/graphql-spqr/src/main/java/com/baeldung/spqr/BookService.java

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+package com.baeldung.spqr;
+
+import io.leangen.graphql.annotations.GraphQLArgument;
+import io.leangen.graphql.annotations.GraphQLMutation;
+import io.leangen.graphql.annotations.GraphQLQuery;
+import io.leangen.graphql.spqr.spring.annotations.GraphQLApi;
+import org.springframework.stereotype.Service;
+
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+@Service
+@GraphQLApi
+public class BookService implements IBookService {
+
+    Set<Book> books = new HashSet<>();
+
+    @GraphQLQuery(name = "getBookWithTitle")
+    public Book getBookWithTitle(@GraphQLArgument(name = "title") String title) {
+        return books.stream()
+            .filter(book -> book.getTitle()
+                .equals(title))
+            .findFirst()
+            .orElse(null);
+    }
+
+    @GraphQLQuery(name = "getAllBooks", description = "Get all books")
+    public List<Book> getAllBooks() {
+        return books.stream()
+            .toList();
+    }
+
+    @GraphQLMutation(name = "addBook")
+    public Book addBook(@GraphQLArgument(name = "newBook") Book book) {
+        books.add(book);
+        return book;
+    }
+
+    @GraphQLMutation(name = "updateBook")
+    public Book updateBook(@GraphQLArgument(name = "modifiedBook") Book book) {
+        books.remove(book);
+        books.add(book);
+        return book;
+    }
+
+    @GraphQLMutation(name = "deleteBook")
+    public boolean deleteBook(@GraphQLArgument(name = "book") Book book) {
+        return books.remove(book);
+    }
+}

graphql/graphql-spqr/src/main/java/com/baeldung/spqr/IBookService.java

@@ -0,0 +1,15 @@
+package com.baeldung.spqr;
+
+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);
+}