JarCastingSpring data GraphQL JPA Demo
Documentation
This spring-data-graphql-jpa-demo project is intended to provide an easy to understand usage showcase of java-data-graphql together with spring-boot-starter-data-graphql-jpa.
The java-data-graphql library is a layer above the great graphql-java library. It generates a graphql schema out of a given configuration which grants the possibility to :
- execute CRUD operations on entities (getById, getAll, save, delete).
- deal with persisted entities and embedded data objects.
- handle dynamic attributes on any entity.
- add custom methods (queries or mutations) to enrich your schema.
- deal with paging, sorting, filtering on queries.
- easily create "data fetchers" for linking this library to the persistence layer of your choice.
This demo project is a showcase of the usage of this library together together with a JPA persistence layer. GraphQL queries and mutations will be automatically converted to database SQL queries.
How to launch the demo
First, checkout the code from github.
-> From command line
mvn install
# Replace XXX with current version (example : XXX = 1.1-SNAPSHOT)
java -jar target/spring-data-graphql-jpa-demo-XXX.jar
-> From your IDE
Run com.daikit.graphql.spring.jpa.demo.ApplicationStarter as a Java application
How to browse the demo
You are now able to browse your schema with graphiql web user interface available at http://localhost:8080/graphiql/index.html
You can run queries and mutations with variables. See next section for samples.
Sample queries and mutations
You can run these sample queries and mutations in graphiql. Variables are to be set in lower left area of the user interface.
Get entity by ID
# query
query getEntity1($id: ID!) {
getEntity1(id: $id) {
id
intAttr
longAttr
stringAttr
embeddedData1 {
stringAttr
}
}
}
# variables
{
"id":"3"
}
Get list of entities
# query retrieving all entities
query getAllEntity5 {
getAllEntity5 {
data {
id
intAttr
stringAttr
}
}
}
# query with paging
query getAllEntity5 {
getAllEntity5(
paging: { limit: 2, offset: 1 }
) {
data {
id
intAttr
stringAttr
}
}
}
# query with ordering
query getAllEntity5 {
getAllEntity5(
orderBy: [
{ field: "intAttr", direction: DESC },
{ field: "stringAttr", direction: DESC }
]
) {
data {
id
intAttr
stringAttr
}
}
}
# query with filtering
# /!\ Filtering only works on int and String types..
# filtering on other types has not been implemented in this demo
query getAllEntity5 {
getAllEntity5(
filter: {
intAttr: { operator: le, value: 5 },
stringAttr: { operator: endsWith, value: "-4" }
}
) {
data {
id
intAttr
stringAttr
}
}
}
Save entity
# mutation
mutation saveEntity1($id: ID, $intAttr: Int, $embeddedData1: EmbeddedData1InputType) {
saveEntity1(data: { id: $id, intAttr: $intAttr, embeddedData1: $embeddedData1}) {
id
intAttr
embeddedData1 {
stringAttr
}
}
}
# variables
{
"id": "3",
"intAttr": 150,
"embeddedData1": {
"stringAttr": "test data1"
}
}
Delete entity
# mutation
mutation deleteEntity1($id: ID!) {
deleteEntity1(id: $id) {
id
typename
}
}
# variables
{
"id": "2"
}
Custom method mutation
# mutation
mutation customMethodMutation1($arg1: String) {
customMethodMutation1(arg1: $arg1) {
stringAttr
}
}
# variables
{
"arg1": "This value should be returned"
}
Custom method query
# query
query customMethodQuery1($arg1: String) {
customMethodQuery1(arg1: $arg1) {
intAttr
stringAttr
embeddedData1 {
stringAttr
}
}
}
# variables
{
"arg1": "This string is set in both returned stringAttr"
}
# query
query customMethodQuery2(
$arg1: String,
$arg2: EmbeddedData1InputType
) {
customMethodQuery2(arg1: $arg1, arg2: $arg2) {
intAttr
stringAttr
embeddedData1 {
intAttr
stringAttr
}
}
}
# variables
{
"arg1": "This string is set in returned stringAttr",
"arg2": {
"intAttr": 2,
"stringAttr": "This string is set in returned embeddedData1"
}
}
# query
query customMethodQuery3(
$arg1: Enum1,
$arg2: [String],
$arg3: [Enum1],
$arg4: [EmbeddedData1InputType],
$arg5: String
) {
customMethodQuery3(
arg1: $arg1,
arg2: $arg2,
arg3: $arg3,
arg4: $arg4,
arg5: $arg5
) {
enumAttr
stringList
enumList
embeddedData1s {
stringAttr
}
stringAttr
}
}
# variables
{
"arg1": "VAL2",
"arg2": ["string1", "string2"],
"arg3": ["VAL1", "VAL2"],
"arg4": [{"stringAttr": "data1"}, {"stringAttr": "data2"}],
"arg5": null
}
# TIP : there is a check on arg5:
# -> if null the set "NULLVALUE" otherwise set as null
Dynamic attribute getter
# query
query getEntity1($id: ID!) {
getEntity1(id: $id) {
id
dynamicAttribute1
}
}
# variables
{
"id": "3"
}
Dynamic attribute setter
# mutation
mutation saveEntity1($id: ID, $dynamicAttribute2: String) {
saveEntity1(data: { id: $id, dynamicAttribute2: $dynamicAttribute2 }) {
id
stringAttr
}
}
# variables
{
"id": "3",
"dynamicAttribute2": "This string is set in stringAttr"
}
Architecture overview
QueryDSL entity paths
In order to be able to automatically convert GraphQL queries to JPA queries, all entities referenced in GraphQL schema must have a corresponding queryDSL entityPath.
These entityPaths are generated thanks to apt-maven-plugin.
Spring data JPA repositories
In order to be able to automatically convert GraphQL queries to JPA queries, all entities referenced in GraphQL schema have a corresponding spring data repository interface extending com.daikit.graphql.spring.jpa.repository.IEntityRepository.
The entity service
The entity service (extending com.daikit.graphql.spring.jpa.service.IEntityService) is providing methods accessible by GraphQL data fetchers for CRUD operations on any entity types. Default implementation com.daikit.graphql.spring.jpa.service.DefaultEntityService is used in this demo, feel free to override it.
Custom hibernate user types
When you want to store data as JSON in a SQL column you need to use hibernate custom org.hibernate.usertype.UserType. These data can then be available in the GraphQL layer thanks to "embedded entities" (set the entity meta data as embedded when building the GraphQL meta model).
Some custom user types have been defined in this project, see com.daikit.graphql.spring.jpa.demo.usertype.impl package content for examples.
Contributing
We accept Pull Requests via GitHub. There are some guidelines which will make applying PRs easier for us:
- No spaces :) Please use tabs for indentation.
- Respect the code style.
- Create minimal diffs - disable on save actions like reformat source code or organize imports. If you feel the source code should be reformatted create a separate PR for this change.
License
This code is under the Apache Licence v2.