MicroProfile GraphQL Example
This is an example of the MicroProfile GraphQL API using the SmallRye Implementation. It's done as part of these blog posts:
and these presentations:
- Upcoming: Global Summit for Java devs'20
- Quarkus Insights
- #OffTheChain
- joziJUG
- SouJava
- DevConf.cz
- Java cloud conference
The services are exposed with both REST and GraphQL for comparison.
Person example
This example expose person data as well as scores that the person got for certain activities.
Running in Quarkus
(generate from https://code.quarkus.io/)
cd quarkus-example
mvn clean install quarkus:dev
Running in Wildfly
cd wildfly-example
mvn clean install wildfly:run
This will start the application on port 8080.
Testing
Go to http://localhost:8080 to test the application.
- Click on the 'REST' link to open Swagger UI to test the JAX-RS services.
- Click on the 'GraphQL' link to open GraphiQL UI to test the MicroProfile GraphQL service.
To stop the application, ctrl-c in the maven session.
Examples
See the model in the JavaDoc (target/apidocs/index.html)
Demo 1 : MicroProfile GraphQL vs JAX-RS
REST
Schema: http://localhost:8080/openapi
curl -X GET "http://localhost:8080/rest/profile/1" -H "accept: application/json"
GraphQL
Schema: http://localhost:8080/graphql/schema.graphql
{
person(id:1){
names
surname
}
}
Demo 2: Stitching
{
person(id:1){
names
surname
scores{
name
value
}
}
}
in the log file:
======= Getting person [1] =======
======= Getting scores [512-46-5065] =======
without score
{
person(id:1){
names
surname
}
}
in the log file:
======= Getting person [1] =======
Demo 3: Batch
{
people{
names
scores{
name
}
}
}
in the log file:
======= Getting scores [797-95-4822, 373-95-3047, 097-87-6795, 347-01-8880, 733-86-4423, 560-99-2165, 091-07-5401, 539-70-2014, 029-18-5986, 287-58-0690] =======
Demo 4: More than one request
{
person1:person(id:1){
surname
scores{
name
value
}
}
person2:person(id:2){
surname
}
}
or more than one query:
@Query
public Integer getRandomNumber(long seed){
Random random = new Random(seed);
return random.nextInt();
}
{
person1:person(id:1){
surname
scores{
name
value
}
}
randomId:randomNumber(seed:11)
}
Demo 5: Collections
{
people {
surname
}
}
Demo 6: JsonB Annotations support
{
person(id:1){
surname
birthDate
}
}
Demo 7: DefaultValue
@Query
public List<Person> getPersonsWithSurname(
@DefaultValue("Doyle") String surname) {
return personService.getPeopleWithSurname(surname);
}
Providing a parameter
{
personsWithSurname(surname:"Hyatt") {
names
}
}
Uing the default
{
personsWithSurname {
names
}
}
Demo 8: Errors and partial responses
Validation Errors
{
person(id:1){
surname
scores{
thisDoesNotExist
}
}
}
Partial results
{
person(id:1){
surname
scores{
name
value
}
}
}
Demo 9: Metrics and Tracing
Servers
This will be specific to your setup. For me:
Start Prometheus:
cd /opt/Metrics/prometheus-2.19.2.linux-amd64
./prometheus --config.file=prometheus.yml
(prometheus.yml is in the root folder)
Start Grafana:
sudo systemctl start grafana-server
(grafana.json is in the root folder)
Start Jaeger:
docker run -p 5775:5775/udp -p 6831:6831/udp -p 6832:6832/udp -p 5778:5778 -p 16686:16686 -p 14268:14268 jaegertracing/all-in-one:latest
Metrics
@Timed(name = "personTimer", description = "How long does it take to get a Person.", unit = MetricUnits.NANOSECONDS)
@Counted(name = "personCount", description = "How many times did we ask for Person.")
Tracing
Demo 10: Security
@RolesAllowed("admin")
Demo 11: Bean validation
@Query
public Integer getRandomNumber(@Min(10) long seed){
Random random = new Random(seed);
return random.nextInt();
}
{
randomNumber(seed:9)
}
Demo 12: Mutations
@Mutation
public Person updatePerson(Person person){
return personService.updateOrCreate(person);
}
@Mutation
public Person deletePerson(Long id){
return personService.delete(id);
}
Create
mutation CreatePerson{
updatePerson(person :
{
names: "Phillip"
}
){
id
names
surname
profilePictures
website
}
}
Update
(using the generated id)
mutation UpdatePerson{
updatePerson(person :
{
id: 11,
names:"Phillip",
surname: "Kruger",
profilePictures: [
"https://pbs.twimg.com/profile_images/1170690050524405762/I8KJ_hF4_400x400.jpg"
],
website: "http://www.phillip-kruger.com"
}){
id
names
surname
profilePictures
website
}
}
Delete
(using the id)
mutation DeletePerson{
deletePerson(id :11){
id
surname
}
}
Demo 13: Context (Experimental)
quarkus.hibernate-orm.log.sql=true
@Inject
Context context;
JsonArray selectedFields = context.getSelectedFields();
System.out.println("selectedFields [" + selectedFields +"]");
{
people{
surname
}
}
Demo 14: Client (Future)
See the model in the JavaDoc (target/apidocs/index.html)
//@Inject
PersonGraphQLClient graphQLClient = GraphQlClientBuilder.newBuilder().build(PersonGraphQLClient.class);
Person graphQLPerson = graphQLClient.getPerson(id);
System.err.println("================ GRAPHQL ================");
System.err.println(graphQLPerson);
Apendix: Introspection
{
__schema{
types {
name
kind
}
}
}
The Introspection query used by GrapiQL
query IntrospectionQuery {
__schema {
queryType { name }
mutationType { name }
subscriptionType { name }
types {
...FullType
}
directives {
name
description
locations
args {
...InputValue
}
}
}
}
fragment FullType on __Type {
kind
name
description
fields(includeDeprecated: true) {
name
description
args {
...InputValue
}
type {
...TypeRef
}
isDeprecated
deprecationReason
}
inputFields {
...InputValue
}
interfaces {
...TypeRef
}
enumValues(includeDeprecated: true) {
name
description
isDeprecated
deprecationReason
}
possibleTypes {
...TypeRef
}
}
fragment InputValue on __InputValue {
name
description
type { ...TypeRef }
defaultValue
}
fragment TypeRef on __Type {
kind
name
ofType {
kind
name
ofType {
kind
name
ofType {
kind
name
ofType {
kind
name
ofType {
kind
name
ofType {
kind
name
ofType {
kind
name
}
}
}
}
}
}
}
}