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Version: 5.x.x

Maven Plugin Goals

GraphQL Kotlin Maven Plugin provides functionality to generate a lightweight GraphQL HTTP client and generate GraphQL schema directly from your source code.

info

This plugin is dependent on Kotlin compiler plugin as it generates Kotlin source code that needs to be compiled.

Goals#

You can find detailed information about graphql-kotlin-maven-plugin and all its goals by running mvn help:describe -Dplugin=com.expediagroup:graphql-kotlin-maven-plugin -Ddetail.

download-sdl#

GraphQL endpoints are often public and as such many servers might disable introspection queries in production environment. Since GraphQL schema is needed to generate type safe clients, as alternative GraphQL servers might expose private endpoints (e.g. accessible only from within network, etc) that could be used to download schema in Schema Definition Language (SDL) directly. This Mojo attempts to download schema from the specified graphql.endpoint, validates the result whether it is a valid schema and saves it locally in a specified target file (defaults to schema.graphql under build directory). In general, this goal provides limited functionality by itself and instead should be used to generate input for the subsequent generate-client goal.

Attributes

  • Default Lifecycle Phase: generate-sources

Parameters

PropertyTypeRequiredDescription
endpointStringyesTarget GraphQL server SDL endpoint that will be used to download schema.
User property is: graphql.endpoint.
headersMap<String, Any>Optional HTTP headers to be specified on a SDL request.
timeoutConfigurationTimeoutConfigurationOptional timeout configuration (in milliseconds) to download schema from SDL endpoint before we cancel the request.
Default values are:
connect timeout = 5000
read timeout = 15000.
schemaFileFileTarget schema file.
Default value is: ${project.build.directory}/schema.graphql
User property is: graphql.schemaFile.

Parameter Details

  • timeoutConfiguration - Timeout configuration that allows you to specify connect and read timeout values in milliseconds.
<timeoutConfiguration>  <!-- timeout values in milliseconds -->  <connect>1000</connect>  <read>30000</read></timeoutConfiguration>

generate-client#

Generate GraphQL client code based on the provided GraphQL schema and target queries.

Attributes

  • Default Lifecycle Phase: generate-sources
  • Requires Maven Project
  • Generated classes are automatically added to the list of compiled sources.

Parameters

PropertyTypeRequiredDescription
allowDeprecatedFieldsBooleanBoolean flag indicating whether selection of deprecated fields is allowed or not.
Default value is: false.
User property is: graphql.allowDeprecatedFields.
customScalarsList<CustomScalar>List of custom GraphQL scalar to converter mappings containing information about corresponding Java type and converter that should be used to serialize/deserialize values.
outputDirectoryFileTarget directory where to store generated files.
Default value is: ${project.build.directory}/generated-sources/graphql
packageNameStringyesTarget package name for generated code.
User property is: graphql.packageName.
queryFileDirectoryFileDirectory file containing GraphQL queries. Instead of specifying a directory you can also specify list of query file by using queryFiles property instead.
Default value is: src/main/resources.
queryFilesList<File>List of query files to be processed. Instead of a list of files to be processed you can also specify queryFileDirectory directory containing all the files. If this property is specified it will take precedence over the corresponding directory property.
serializerGraphQLSerializerJSON serializer that will be used to generate the data classes.
Default value is: GraphQLSerializer.JACKSON.
schemaFileStringGraphQL schema file that will be used to generate client code.
Default value is: ${project.build.directory}/schema.graphql
User property is: graphql.schemaFile.
useOptionalInputWrapperBooleanBoolean opt-in flag to wrap nullable arguments in OptionalInput that distinguish between null and undefined/omitted value.
Default value is: false.
User property is: graphql.useOptionalInputWrapper

Parameter Details

  • customScalars - List of custom GraphQL scalars. Objects contain target GraphQL scalar name, corresponding Java type and converter that should be used to serialize/deserialize values.

    <customScalars>    <customScalar>        <!-- custom scalar UUID type -->        <scalar>UUID</scalar>        <!-- fully qualified Java class name of a custom scalar type -->        <type>java.util.UUID</type>        <!-- fully qualified Java class name of a custom com.expediagroup.graphql.client.converter.ScalarConverter          used to convert to/from raw JSON and scalar type -->        <converter>com.example.UUIDScalarConverter</converter>    </customScalar></customScalars>

generate-sdl#

Generates GraphQL schema in SDL format from your source code using reflections. Utilizes graphql-kotlin-schema-generator to generate the schema from classes implementing graphql-kotlin-server marker Query, Mutation and Subscription interfaces. In order to limit the amount of packages to scan, this mojo requires users to provide a list of packages that can contain GraphQL types.

This MOJO utilizes ServiceLoader mechanism to dynamically load available SchemaGeneratorHooksProvider service providers from the classpath. Service provider can be provided as part of your project, included in one of your project dependencies or through explicitly provided artifact. See Schema Generator Hooks Provider for additional details on how to create custom hooks service provider. Configuration below shows how to configure GraphQL Kotlin plugin with explicitly provided artifact.

Attributes

  • Default Lifecycle Phase: process-classes
  • Requires Maven Project

Parameters

PropertyTypeRequiredDescription
packagesList<String>yesList of supported packages that can be scanned to generate SDL.
schemaFileFileTarget GraphQL schema file to be generated.
Default value is: ${project.buildDir}/schema.graphql

generate-test-client#

Generate GraphQL test client code based on the provided GraphQL schema and target queries.

Attributes

  • Default Lifecycle Phase: generate-test-sources
  • Requires Maven Project
  • Generated classes are automatically added to the list of test compiled sources.

Parameters

PropertyTypeRequiredDescription
allowDeprecatedFieldsBooleanBoolean flag indicating whether selection of deprecated fields is allowed or not.
Default value is: false.
User property is: graphql.allowDeprecatedFields.
customScalarsList<CustomScalar>List of custom GraphQL scalar to converter mappings containing information about corresponding Java type and converter that should be used to serialize/deserialize values.
outputDirectoryFileTarget directory where to store generated files.
Default value is: ${project.build.directory}/generated-test-sources/graphql
packageNameStringyesTarget package name for generated code.
User property is: graphql.packageName.
queryFileDirectoryFileDirectory file containing GraphQL queries. Instead of specifying a directory you can also specify list of query file by using queryFiles property instead.
Default value is: src/test/resources.
queryFilesList<File>List of query files to be processed. Instead of a list of files to be processed you can also specify queryFileDirectory directory containing all the files. If this property is specified it will take precedence over the corresponding directory property.
serializerGraphQLSerializerJSON serializer that will be used to generate the data classes.
Default value is: GraphQLSerializer.JACKSON.
schemaFileStringGraphQL schema file that will be used to generate client code.
Default value is: ${project.build.directory}/schema.graphql
User property is: graphql.schemaFile.
useOptionalInputWrapperBooleanBoolean opt-in flag to wrap nullable arguments in OptionalInput that distinguish between null and undefined/omitted value.
Default value is: false.
User property is: graphql.useOptionalInputWrapper

Parameter Details

  • customScalars - List of custom GraphQL scalars. Objects contain target GraphQL scalar name, corresponding Java type and converter that should be used to serialize/deserialize values.

<customScalars>  <customScalar>      <!-- custom scalar UUID type -->      <scalar>UUID</scalar>      <!-- fully qualified Java class name of a custom scalar type -->      <type>java.util.UUID</type>      <!-- fully qualified Java class name of a custom com.expediagroup.graphql.client.converter.ScalarConverter        used to convert to/from raw JSON and scalar type -->      <converter>com.example.UUIDScalarConverter</converter>  </customScalar></customScalars>

introspect-schema#

Executes GraphQL introspection query against specified graphql.endpoint and saves the result locally to a target file (defaults to schema.graphql under build directory). In general, this goal provides limited functionality by itself and instead should be used to generate input for the subsequent generate-client goal.

Attributes

  • Default Lifecycle Phase: generate-sources

Parameters

PropertyTypeRequiredDescription
endpointStringyesTarget GraphQL server endpoint that will be used to execute introspection queries.
User property is: graphql.endpoint.
headersMap<String, Any>Optional HTTP headers to be specified on an introspection query.
timeoutConfigurationTimeoutConfigurationOptional timeout configuration (in milliseconds) to download schema from SDL endpoint before we cancel the request.
Default values are:
connect timeout = 5000
read timeout = 15000.
schemaFileFileTarget schema file.
Default value is: ${project.build.directory}/schema.graphql
User property is: graphql.schemaFile.

Parameter Details

  • timeoutConfiguration - Timeout configuration that allows you to specify connect and read timeout values in milliseconds.
<timeoutConfiguration>  <!-- timeout values in milliseconds -->  <connect>1000</connect>  <read>30000</read></timeoutConfiguration>