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Documentation for the java Generator

METADATA

PropertyValueNotes
generator namejavapass this to the generate command after -g
generator stabilitySTABLE
generator typeCLIENT
generator languageJava
generator default templating enginemustache
helpTxtGenerates a Java client library (HTTP lib: Jersey (1.x, 2.x), Retrofit (2.x), OpenFeign (10.x) and more.

CONFIG OPTIONS

These options may be applied as additional-properties (cli) or configOptions (plugins). Refer to configuration docs for more details.

OptionDescriptionValuesDefault
additionalEnumTypeAnnotationsAdditional annotations for enum type(class level annotations)null
additionalModelTypeAnnotationsAdditional annotations for model type(class level annotations). List separated by semicolon(;) or new line (Linux or Windows)null
additionalOneOfTypeAnnotationsAdditional annotations for oneOf interfaces(class level annotations). List separated by semicolon(;) or new line (Linux or Windows)null
allowUnicodeIdentifiersboolean, toggles whether unicode identifiers are allowed in names or not, default is falsefalse
annotationLibrarySelect the complementary documentation annotation library.
none
Do not annotate Model and Api with complementary annotations.
swagger1
Annotate Model and Api using the Swagger Annotations 1.x library.
swagger2
Annotate Model and Api using the Swagger Annotations 2.x library.
none
apiPackagepackage for generated api classesorg.openapitools.client.api
artifactDescriptionartifact description in generated pom.xmlOpenAPI Java
artifactIdartifactId in generated pom.xml. This also becomes part of the generated library's filenameopenapi-java-client
artifactUrlartifact URL in generated pom.xmlhttps://github.com/openapitools/openapi-generator
artifactVersionartifact version in generated pom.xml. This also becomes part of the generated library's filename. If not provided, uses the version from the OpenAPI specification file. If that's also not present, uses the default value of the artifactVersion option.1.0.0
asyncNativeIf true, async handlers will be used, instead of the sync versionfalse
bigDecimalAsStringTreat BigDecimal values as Strings to avoid precision loss.false
booleanGetterPrefixSet booleanGetterPrefixget
camelCaseDollarSignFix camelCase when starting with $ sign. when true : $Value when false : $valuefalse
caseInsensitiveResponseHeadersMake API response's headers case-insensitive. Available on okhttp-gson, jersey2 librariesfalse
configKeyConfig key in @RegisterRestClient. Default to none. Only microprofile supports this option.null
configKeyFromClassNameIf true, set tag as key in @RegisterRestClient. Default to false. Only microprofile supports this option.null
containerDefaultToNullSet containers (array, set, map) default to nullfalse
dateLibraryOption. Date library to use
joda
Joda (for legacy app only)
legacy
Legacy java.util.Date
java8-localdatetime
Java 8 using LocalDateTime (for legacy app only)
java8
Java 8 native JSR310 (preferred for jdk 1.8+)
java8
developerEmaildeveloper email in generated pom.xmlteam@openapitools.org
developerNamedeveloper name in generated pom.xmlOpenAPI-Generator Contributors
developerOrganizationdeveloper organization in generated pom.xmlOpenAPITools.org
developerOrganizationUrldeveloper organization URL in generated pom.xmlhttp://openapitools.org
disableHtmlEscapingDisable HTML escaping of JSON strings when using gson (needed to avoid problems with byte[] fields)false
disallowAdditionalPropertiesIfNotPresentIf false, the 'additionalProperties' implementation (set to true by default) is compliant with the OAS and JSON schema specifications. If true (default), keep the old (incorrect) behaviour that 'additionalProperties' is set to false by default.
false
The 'additionalProperties' implementation is compliant with the OAS and JSON schema specifications.
true
Keep the old (incorrect) behaviour that 'additionalProperties' is set to false by default.
true
discriminatorCaseSensitiveWhether the discriminator value lookup should be case-sensitive or not. This option only works for Java API clienttrue
documentationProviderSelect the OpenAPI documentation provider.
none
Do not publish an OpenAPI specification.
source
Publish the original input OpenAPI specification.
source
dynamicOperationsGenerate operations dynamically at runtime from an OASfalse
ensureUniqueParamsWhether to ensure parameter names are unique in an operation (rename parameters that are not).true
enumUnknownDefaultCaseIf the server adds new enum cases, that are unknown by an old spec/client, the client will fail to parse the network response.With this option enabled, each enum will have a new case, 'unknown_default_open_api', so that when the server sends an enum case that is not known by the client/spec, they can safely fallback to this case.
false
No changes to the enum's are made, this is the default option.
true
With this option enabled, each enum will have a new case, 'unknown_default_open_api', so that when the enum case sent by the server is not known by the client/spec, can safely be decoded to this case.
false
errorObjectTypeError Object type. (This option is for okhttp-gson only)null
failOnUnknownPropertiesFail Jackson de-serialization on unknown propertiesfalse
generateBuildersWhether to generate builders for modelsfalse
generateClientAsBeanFor resttemplate, configure whether to create ApiClient.java and Apis clients as bean (with @Component annotation).false
generateConstructorWithAllArgswhether to generate a constructor for all argumentsfalse
gradlePropertiesAppend additional Gradle properties to the gradle.properties filenull
groupIdgroupId in generated pom.xmlorg.openapitools
hideGenerationTimestampHides the generation timestamp when files are generated.false
ignoreAnyOfInEnumIgnore anyOf keyword in enumfalse
implicitHeadersSkip header parameters in the generated API methods using @ApiImplicitParams annotation.false
implicitHeadersRegexSkip header parameters that matches given regex in the generated API methods using @ApiImplicitParams annotation. Note: this parameter is ignored when implicitHeaders=truenull
invokerPackageroot package for generated codeorg.openapitools.client
legacyDiscriminatorBehaviorSet to false for generators with better support for discriminators. (Python, Java, Go, PowerShell, C# have this enabled by default).
true
The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.
false
The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.
true
librarylibrary template (sub-template) to use
jersey2
HTTP client: Jersey client 2.25.1. JSON processing: Jackson 2.17.1
jersey3
HTTP client: Jersey client 3.1.1. JSON processing: Jackson 2.17.1
feign
HTTP client: OpenFeign 13.2.1. JSON processing: Jackson 2.17.1 or Gson 2.10.1
okhttp-gson
[DEFAULT] HTTP client: OkHttp 4.11.0. JSON processing: Gson 2.10.1. Enable Parcelable models on Android using '-DparcelableModel=true'. Enable gzip request encoding using '-DuseGzipFeature=true'.
retrofit2
HTTP client: OkHttp 4.11.0. JSON processing: Gson 2.10.1 (Retrofit 2.5.0) or Jackson 2.17.1. Enable the RxJava adapter using '-DuseRxJava[2/3]=true'. (RxJava 1.x or 2.x or 3.x)
resttemplate
HTTP client: Spring RestTemplate 5.3.33 (6.1.5 if useJakartaEe=true). JSON processing: Jackson 2.17.1
webclient
HTTP client: Spring WebClient 5.1.18. JSON processing: Jackson 2.17.1
restclient
HTTP client: Spring RestClient 6.1.6. JSON processing: Jackson 2.17.1
resteasy
HTTP client: Resteasy client 4.7.6. JSON processing: Jackson 2.17.1
vertx
HTTP client: VertX client 3.5.2. JSON processing: Jackson 2.17.1
google-api-client
HTTP client: Google API client 2.2.0. JSON processing: Jackson 2.17.1
rest-assured
HTTP client: rest-assured 5.3.2. JSON processing: Gson 2.10.1 or Jackson 2.17.1. Only for Java 8
native
HTTP client: Java native HttpClient. JSON processing: Jackson 2.17.1. Only for Java11+
microprofile
HTTP client: Microprofile client 2.0 (default, set desired version via microprofileRestClientVersion=x.x.x). JSON processing: JSON-B 1.0.2 or Jackson 2.17.1
apache-httpclient
HTTP client: Apache httpclient 5.2.1. JSON processing: Jackson 2.17.1
okhttp-gson
licenseNameThe name of the licenseUnlicense
licenseUrlThe URL of the licensehttp://unlicense.org
microprofileFrameworkFramework for microprofile. Possible values "kumuluzee"null
microprofileMutinyWhether to use async types for microprofile (currently only Smallrye Mutiny is supported).null
microprofileRestClientVersionVersion of MicroProfile Rest Client API.null
modelPackagepackage for generated modelsorg.openapitools.client.model
openApiNullableEnable OpenAPI Jackson Nullable librarytrue
parcelableModelWhether to generate models for Android that implement Parcelable with the okhttp-gson library.false
parentArtifactIdparent artifactId in generated pom N.B. parentGroupId, parentArtifactId and parentVersion must all be specified for any of them to take effectnull
parentGroupIdparent groupId in generated pom N.B. parentGroupId, parentArtifactId and parentVersion must all be specified for any of them to take effectnull
parentVersionparent version in generated pom N.B. parentGroupId, parentArtifactId and parentVersion must all be specified for any of them to take effectnull
performBeanValidationPerform BeanValidationfalse
prependFormOrBodyParametersAdd form or body parameters to the beginning of the parameter list.false
scmConnectionSCM connection in generated pom.xmlscm:git:git@github.com:openapitools/openapi-generator.git
scmDeveloperConnectionSCM developer connection in generated pom.xmlscm:git:git@github.com:openapitools/openapi-generator.git
scmUrlSCM URL in generated pom.xmlhttps://github.com/openapitools/openapi-generator
serializableModelboolean - toggle "implements Serializable" for generated modelsfalse
serializationLibrarySerialization library, default depends on value of the option library
jsonb
Use JSON-B as serialization library
jackson
Use Jackson as serialization library
gson
Use Gson as serialization library
null
snapshotVersionUses a SNAPSHOT version.
true
Use a SnapShot Version
false
Use a Release Version
null
sortModelPropertiesByRequiredFlagSort model properties to place required parameters before optional parameters.true
sortParamsByRequiredFlagSort method arguments to place required parameters before optional parameters.true
sourceFoldersource folder for generated codesrc/main/java
supportStreamingSupport streaming endpoint (beta)false
supportUrlQueryGenerate toUrlQueryString in POJO (default to true). Available on native, apache-httpclient libraries.false
testOutputSet output folder for models and APIs tests${project.build.directory}/generated-test-sources/openapi
useAbstractionForFilesUse alternative types instead of java.io.File to allow passing bytes without a file on disk. Available on resttemplate, webclient, restclient, librariesfalse
useBeanValidationUse BeanValidation API annotationsfalse
useEnumCaseInsensitiveUse equalsIgnoreCase when String for enum comparisonfalse
useGzipFeatureSend gzip-encoded requestsfalse
useJakartaEewhether to use Jakarta EE namespace instead of javaxfalse
useOneOfDiscriminatorLookupUse the discriminator's mapping in oneOf to speed up the model lookup. IMPORTANT: Validation (e.g. one and only one match in oneOf's schemas) will be skipped. Only jersey2, jersey3, native, okhttp-gson support this option.false
useOneOfInterfaceswhether to use a java interface to describe a set of oneOf options, where each option is a class that implements the interfacefalse
usePlayWSUse Play! Async HTTP client (Play WS API)false
useReflectionEqualsHashCodeUse org.apache.commons.lang3.builder for equals and hashCode in the models. WARNING: This will fail under a security manager, unless the appropriate permissions are set up correctly and also there's potential performance impact.false
useRuntimeExceptionUse RuntimeException instead of Exception. Only jersey2, jersey3, okhttp-gson, vertx, microprofile support this option.false
useRxJava2Whether to use the RxJava2 adapter with the retrofit2 library. IMPORTANT: This option has been deprecated.false
useRxJava3Whether to use the RxJava3 adapter with the retrofit2 library. IMPORTANT: This option has been deprecated.false
useSingleRequestParameterSetting this property to true will generate functions with a single argument containing all API endpoint parameters instead of one argument per parameter. ONLY jersey2, jersey3, okhttp-gson, microprofile, Spring RestClient support this option.false
webclientBlockingOperationsMaking all WebClient operations blocking(sync). Note that if on operation 'x-webclient-blocking: false' then such operation won't be syncfalse
withAWSV4Signaturewhether to include AWS v4 signature support (only available for okhttp-gson library)false
withXmlwhether to include support for application/xml content type and include XML annotations in the model (works with libraries that provide support for JSON and XML)false

SUPPORTED VENDOR EXTENSIONS

Extension nameDescriptionApplicable forDefault value
x-discriminator-valueUsed with model inheritance to specify value for discriminator that identifies current modelMODEL
x-implementsAbility to specify interfaces that model must implementsMODELempty array
x-setter-extra-annotationCustom annotation that can be specified over java setter for specific fieldFIELDWhen field is array & uniqueItems, then this extension is used to add @JsonDeserialize(as = LinkedHashSet.class) over setter, otherwise no value
x-tagsSpecify multiple swagger tags for operationOPERATIONnull
x-acceptsSpecify custom value for 'Accept' header for operationOPERATIONnull
x-content-typeSpecify custom value for 'Content-Type' header for operationOPERATIONnull
x-class-extra-annotationList of custom annotations to be added to modelMODELnull
x-field-extra-annotationList of custom annotations to be added to propertyFIELD, OPERATION_PARAMETERnull
x-webclient-blockingSpecifies if method for specific operation should be blocking or non-blocking(ex: return Mono<T>/Flux<T> or return T/List<T>/Set<T> & execute .block() inside generated method)OPERATIONfalse

IMPORT MAPPING

Type/AliasImports
Arrayjava.util.List
ArrayListjava.util.ArrayList
BigDecimaljava.math.BigDecimal
Datejava.util.Date
DateTimeorg.joda.time.*
Filejava.io.File
HashMapjava.util.HashMap
LinkedHashSetjava.util.LinkedHashSet
Listjava.util.*
LocalDateorg.joda.time.*
LocalDateTimeorg.joda.time.*
LocalTimeorg.joda.time.*
Mapjava.util.Map
Setjava.util.*
Timestampjava.sql.Timestamp
URIjava.net.URI
UUIDjava.util.UUID

INSTANTIATION TYPES

Type/AliasInstantiated By
arrayArrayList
mapHashMap
setLinkedHashSet

LANGUAGE PRIMITIVES

  • Boolean
  • Double
  • Float
  • Integer
  • Long
  • Object
  • String
  • boolean
  • byte[]

RESERVED WORDS

  • _
  • abstract
  • apiclient
  • apiexception
  • apiresponse
  • assert
  • boolean
  • break
  • byte
  • case
  • catch
  • char
  • class
  • configuration
  • const
  • continue
  • default
  • do
  • double
  • else
  • enum
  • extends
  • file
  • final
  • finally
  • float
  • for
  • goto
  • if
  • implements
  • import
  • instanceof
  • int
  • interface
  • list
  • localdate
  • localreturntype
  • localtime
  • localvaraccept
  • localvaraccepts
  • localvarauthnames
  • localvarcollectionqueryparams
  • localvarcontenttype
  • localvarcontenttypes
  • localvarcookieparams
  • localvarformparams
  • localvarheaderparams
  • localvarpath
  • localvarpostbody
  • localvarqueryparams
  • long
  • native
  • new
  • null
  • object
  • offsetdatetime
  • package
  • private
  • protected
  • public
  • return
  • short
  • static
  • strictfp
  • stringutil
  • super
  • switch
  • synchronized
  • this
  • throw
  • throws
  • transient
  • try
  • void
  • volatile
  • while

FEATURE SET

Client Modification Feature

NameSupportedDefined By
BasePathToolingExtension
AuthorizationsToolingExtension
UserAgentToolingExtension
MockServerToolingExtension

Data Type Feature

NameSupportedDefined By
CustomOAS2,OAS3
Int32OAS2,OAS3
Int64OAS2,OAS3
FloatOAS2,OAS3
DoubleOAS2,OAS3
DecimalToolingExtension
StringOAS2,OAS3
ByteOAS2,OAS3
BinaryOAS2,OAS3
BooleanOAS2,OAS3
DateOAS2,OAS3
DateTimeOAS2,OAS3
PasswordOAS2,OAS3
FileOAS2
Uuid
ArrayOAS2,OAS3
NullOAS3
AnyTypeOAS2,OAS3
ObjectOAS2,OAS3
MapsToolingExtension
CollectionFormatOAS2
CollectionFormatMultiOAS2
EnumOAS2,OAS3
ArrayOfEnumToolingExtension
ArrayOfModelToolingExtension
ArrayOfCollectionOfPrimitivesToolingExtension
ArrayOfCollectionOfModelToolingExtension
ArrayOfCollectionOfEnumToolingExtension
MapOfEnumToolingExtension
MapOfModelToolingExtension
MapOfCollectionOfPrimitivesToolingExtension
MapOfCollectionOfModelToolingExtension
MapOfCollectionOfEnumToolingExtension

Documentation Feature

NameSupportedDefined By
ReadmeToolingExtension
ModelToolingExtension
ApiToolingExtension

Global Feature

NameSupportedDefined By
HostOAS2,OAS3
BasePathOAS2,OAS3
InfoOAS2,OAS3
SchemesOAS2,OAS3
PartialSchemesOAS2,OAS3
ConsumesOAS2
ProducesOAS2
ExternalDocumentationOAS2,OAS3
ExamplesOAS2,OAS3
XMLStructureDefinitionsOAS2,OAS3
MultiServerOAS3
ParameterizedServerOAS3
ParameterStylingOAS3
CallbacksOAS3
LinkObjectsOAS3

Parameter Feature

NameSupportedDefined By
PathOAS2,OAS3
QueryOAS2,OAS3
HeaderOAS2,OAS3
BodyOAS2
FormUnencodedOAS2
FormMultipartOAS2
CookieOAS3

Schema Support Feature

NameSupportedDefined By
SimpleOAS2,OAS3
CompositeOAS2,OAS3
PolymorphismOAS2,OAS3
UnionOAS3
allOfOAS2,OAS3
anyOfOAS3
oneOfOAS3
notOAS3

Security Feature

NameSupportedDefined By
BasicAuthOAS2,OAS3
ApiKeyOAS2,OAS3
OpenIDConnectOAS3
BearerTokenOAS3
OAuth2_ImplicitOAS2,OAS3
OAuth2_PasswordOAS2,OAS3
OAuth2_ClientCredentialsOAS2,OAS3
OAuth2_AuthorizationCodeOAS2,OAS3
SignatureAuthOAS3
AWSV4SignatureToolingExtension

Wire Format Feature

NameSupportedDefined By
JSONOAS2,OAS3
XMLOAS2,OAS3
PROTOBUFToolingExtension
CustomOAS2,OAS3