Add example for integrating with new Spring GraphQL

examples/graphql-spring-boot/pom.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <parent>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-starter-parent</artifactId>
+        <version>2.7.0-M1</version>
+        <relativePath/> <!-- lookup parent from repository -->
+    </parent>
+
+    <groupId>org.neo4j.graphql.examples</groupId>
+    <artifactId>graphql-spring-boot</artifactId>
+    <version>1.0-SNAPSHOT</version>
+
+    <name>Example - graphql-spring-boot</name>
+    <description>Example for using neo4j-graphql-java with Spring Boot</description>
+
+    <properties>
+        <java.version>11</java.version>
+        <testcontainers.version>1.16.2</testcontainers.version>
+    </properties>
+
+    <dependencies>
+        <!-- spring dependencies -->
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-configuration-processor</artifactId>
+            <optional>true</optional>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-graphql</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+        </dependency>
+
+        <!-- neo4j driver + the neo4j-graphql-java library -->
+        <dependency>
+            <groupId>org.neo4j.driver</groupId>
+            <artifactId>neo4j-java-driver-spring-boot-starter</artifactId>
+            <version>4.2.7.0</version>
+        </dependency>
+        <dependency>
+            <groupId>org.neo4j</groupId>
+            <artifactId>neo4j-graphql-java</artifactId>
+            <version>1.5.1-SNAPSHOT</version>
+        </dependency>
+
+
+        <!-- Test dependencies -->
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework</groupId>
+            <artifactId>spring-webflux</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.graphql</groupId>
+            <artifactId>spring-graphql-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.testcontainers</groupId>
+            <artifactId>neo4j</artifactId>
+            <version>${testcontainers.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.testcontainers</groupId>
+            <artifactId>junit-jupiter</artifactId>
+            <version>${testcontainers.version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-maven-plugin</artifactId>
+            </plugin>
+        </plugins>
+    </build>
+
+    <repositories>
+        <!-- TODO remove after release of Spring Boot 2.7 -->
+        <repository>
+            <id>spring-milestones</id>
+            <name>Spring Milestones</name>
+            <url>https://repo.spring.io/milestone</url>
+            <snapshots>
+                <enabled>false</enabled>
+            </snapshots>
+        </repository>
+    </repositories>
+    <pluginRepositories>
+        <pluginRepository>
+            <id>spring-milestones</id>
+            <name>Spring Milestones</name>
+            <url>https://repo.spring.io/milestone</url>
+            <snapshots>
+                <enabled>false</enabled>
+            </snapshots>
+        </pluginRepository>
+    </pluginRepositories>
+
+</project>

examples/graphql-spring-boot/readme.adoc

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+= Example: Integration of Neo4j-GraphQL-Java into a Spring Boot  application using Springs GraphQL
+
+== Overview
+
+This example uses the https://docs.spring.io/spring-graphql/docs/1.0.0-SNAPSHOT/reference/html/[Springs new GraphQL library]
+
+In the link:src/main/java/org/neo4j/graphql/examples/graphqlspringboot/config/Neo4jConfiguration.java[Neo4jConfiguration]
+a DataFetchingInterceptor is created, which will be bound to all fields augmented by the neo4j-graphql-library.
+Its purpose is the execution of the cypher query and the transformation of the query result.
+
+In the link:src/main/java/org/neo4j/graphql/examples/graphqlspringboot/config/GraphQLConfiguration.java[GraphQLConfiguration]
+the type definitions of link:src/main/resources/neo4j.graphql[schema] are loaded and augmented.
+
+In this example some fields of the enhanced type (neo4j) are extended with
+link:src/main/java/org/neo4j/graphql/examples/graphqlspringboot/datafetcher/AdditionalDataFetcher.java[custom data fetcher] whose link:src/main/resources/graphql/schema.graphqls[schema is separately defined].
+
+With This in place you can
+
+== Run the example
+
+1. link:src/main/resources/application.yaml[configure your neo4j db] or use a public one
+2. run the link:src/main/java/org/neo4j/graphql/examples/graphqlspringboot/GraphqlSpringBootApplication.java[spring boot application]
+3. open http://localhost:8080/graphiql to run some graphql queries e.g. try:
+
+```graphql
+query{
+  other
+  movies (options: {limit: 3}){
+    title
+    bar
+    javaData {
+      name
+    }
+  }
+}
+```

examples/graphql-spring-boot/src/main/java/org/neo4j/graphql/examples/graphqlspringboot/GraphqlSpringBootApplication.java

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+package org.neo4j.graphql.examples.graphqlspringboot;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class GraphqlSpringBootApplication {
+
+    public static void main(String[] args) {
+        SpringApplication.run(GraphqlSpringBootApplication.class, args);
+    }
+
+}

examples/graphql-spring-boot/src/main/java/org/neo4j/graphql/examples/graphqlspringboot/config/GraphQLConfiguration.java

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+package org.neo4j.graphql.examples.graphqlspringboot.config;
+
+import graphql.schema.GraphQLCodeRegistry;
+import graphql.schema.idl.SchemaGenerator;
+import graphql.schema.idl.SchemaParser;
+import graphql.schema.idl.TypeDefinitionRegistry;
+import org.neo4j.graphql.DataFetchingInterceptor;
+import org.neo4j.graphql.SchemaBuilder;
+import org.neo4j.graphql.SchemaConfig;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.boot.autoconfigure.graphql.GraphQlSourceBuilderCustomizer;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.core.io.Resource;
+
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.util.List;
+
+@Configuration
+public class GraphQLConfiguration {
+
+    @Value("classpath:neo4j.graphql")
+    public Resource graphQl;
+
+    @Autowired(required = false)
+    public DataFetchingInterceptor dataFetchingInterceptor;
+
+    @Bean
+    public GraphQlSourceBuilderCustomizer graphQlSourceBuilderCustomizer() throws IOException {
+
+        String schema = new String(graphQl.getInputStream().readAllBytes(), StandardCharsets.UTF_8);
+
+        TypeDefinitionRegistry neo4jTypeDefinitionRegistry = new SchemaParser().parse(schema);
+        SchemaBuilder schemaBuilder = new SchemaBuilder(neo4jTypeDefinitionRegistry, new SchemaConfig(
+                new SchemaConfig.CRUDConfig(),
+                new SchemaConfig.CRUDConfig(false, List.of()),
+                false, true, SchemaConfig.InputStyle.INPUT_TYPE, true, false));
+        schemaBuilder.augmentTypes();
+
+        return builder -> builder
+                .configureRuntimeWiring(runtimeWiringBuilder -> {
+                    schemaBuilder.registerTypeNameResolver(runtimeWiringBuilder);
+                    schemaBuilder.registerScalars(runtimeWiringBuilder);
+                    GraphQLCodeRegistry.Builder codeRegistryBuilder = GraphQLCodeRegistry.newCodeRegistry();
+                    schemaBuilder.registerDataFetcher(codeRegistryBuilder, dataFetchingInterceptor);
+                    runtimeWiringBuilder.codeRegistry(codeRegistryBuilder);
+                })
+                .schemaFactory((typeDefinitionRegistry, runtimeWiring) -> {
+                    typeDefinitionRegistry.merge(neo4jTypeDefinitionRegistry);
+                    return new SchemaGenerator().makeExecutableSchema(typeDefinitionRegistry, runtimeWiring);
+                });
+    }
+}

examples/graphql-spring-boot/src/main/java/org/neo4j/graphql/examples/graphqlspringboot/config/Neo4jConfiguration.java

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+package org.neo4j.graphql.examples.graphqlspringboot.config;
+
+import graphql.schema.GraphQLList;
+import graphql.schema.GraphQLNonNull;
+import graphql.schema.GraphQLType;
+import org.neo4j.driver.Driver;
+import org.neo4j.driver.Result;
+import org.neo4j.driver.SessionConfig;
+import org.neo4j.graphql.Cypher;
+import org.neo4j.graphql.DataFetchingInterceptor;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+import java.math.BigDecimal;
+import java.math.BigInteger;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+/**
+ * Configuration of the DataFetchingInterceptor
+ */
+@Configuration
+public class Neo4jConfiguration {
+
+    /**
+     * This interceptor is bound to all the graphql fields generated by the neo4j-graphql-library.
+     * Its purpose is the execution of the cypher query and the transformation of the query result.
+     */
+    @Bean
+    public DataFetchingInterceptor dataFetchingInterceptor(
+            Driver driver,
+            @Value("${database}") String database) {
+        return (env, delegate) -> {
+            Cypher cypher = delegate.get(env);
+            return driver.session(SessionConfig.forDatabase(database)).writeTransaction(tx -> {
+                Map<String, Object> boltParams = new HashMap<>(cypher.getParams());
+                boltParams.replaceAll((key, value) -> toBoltValue(value));
+
+                Result result = tx.run(cypher.getQuery(), boltParams);
+                if (isListType(cypher.getType())) {
+                    return result.list()
+                            .stream()
+                            .map(record -> record.get(cypher.getVariable()).asObject())
+                            .collect(Collectors.toList());
+                } else {
+                    return result.list()
+                            .stream()
+                            .map(record -> record.get(cypher.getVariable()).asObject())
+                            .collect(Collectors.toList())
+                            .stream().findFirst()
+                            .orElse(Collections.emptyMap());
+                }
+            });
+        };
+    }
+
+    private Object toBoltValue(Object value) {
+        if (value instanceof BigInteger) {
+            return ((BigInteger) value).longValueExact();
+        }
+        if (value instanceof BigDecimal) {
+            return ((BigDecimal) value).doubleValue();
+        }
+        return value;
+    }
+
+    private boolean isListType(GraphQLType type) {
+        if (type instanceof GraphQLList) {
+            return true;
+        }
+        return type instanceof GraphQLNonNull
+                && this.isListType(((GraphQLNonNull) type).getWrappedType());
+    }
+}

examples/graphql-spring-boot/src/main/java/org/neo4j/graphql/examples/graphqlspringboot/datafetcher/AdditionalDataFetcher.java

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+package org.neo4j.graphql.examples.graphqlspringboot.datafetcher;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+import graphql.schema.DataFetchingEnvironment;
+import org.springframework.graphql.data.method.annotation.QueryMapping;
+import org.springframework.graphql.data.method.annotation.SchemaMapping;
+import org.springframework.stereotype.Controller;
+
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+
+@Controller
+class AdditionalDataFetcher {
+
+    @SchemaMapping(typeName = "Movie", field = "bar")
+    public String bar() {
+        return "foo";
+    }
+
+    @SchemaMapping(typeName = "Movie", field = "javaData")
+    public List<JavaData> javaData(DataFetchingEnvironment env) {
+        //noinspection unchecked
+        Object title = ((Map<String, Object>) env.getSource()).get("title");
+        return Collections.singletonList(new JavaData("test " + title));
+    }
+
+    @QueryMapping
+    public String other() {
+        return "other";
+    }
+
+    public static class JavaData {
+        @JsonProperty("name")
+        public String name;
+
+        public JavaData(String name) {
+            this.name = name;
+        }
+    }
+}

examples/graphql-spring-boot/src/main/resources/application.yaml

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+org :
+  neo4j :
+    driver :
+      uri : bolt://demo.neo4jlabs.com:7687
+      authentication :
+        username : movies
+        password : movies
+      config :
+        encrypted : true
+database : movies
+spring :
+  graphql :
+    schema :
+      printer :
+        enabled : true
+    graphiql :
+      enabled : true

examples/graphql-spring-boot/src/main/resources/graphql/schema.graphqls

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+extend type Movie {
+    bar: String @ignore
+    javaData: [JavaData!] @ignore
+}
+
+type JavaData {
+    name: String
+}
+
+extend type Query {
+    other: String
+}

examples/graphql-spring-boot/src/main/resources/neo4j.graphql

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+type Movie {
+  title: String
+}