--- title: Documentation for the java Generator --- ## METADATA | Property | Value | Notes | | -------- | ----- | ----- | | generator name | java | pass this to the generate command after -g | | generator stability | STABLE | | | generator type | CLIENT | | | generator language | Java | | | generator default templating engine | mustache | | | helpTxt | Generates 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](https://openapi-generator.tech/docs/configuration) for more details. | Option | Description | Values | Default | | ------ | ----------- | ------ | ------- | |additionalEnumTypeAnnotations|Additional annotations for enum type(class level annotations)| |null| |additionalModelTypeAnnotations|Additional annotations for model type(class level annotations). List separated by semicolon(;) or new line (Linux or Windows)| |null| |additionalOneOfTypeAnnotations|Additional annotations for oneOf interfaces(class level annotations). List separated by semicolon(;) or new line (Linux or Windows)| |null| |allowUnicodeIdentifiers|boolean, toggles whether unicode identifiers are allowed in names or not, default is false| |false| |annotationLibrary|Select 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.

**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+)

**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.

**none**: Do not publish an OpenAPI specification.
**source**: Publish the original input OpenAPI specification.

|source| |dynamicOperations|Generate operations dynamically at runtime from an OAS| |false| |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true| |enumUnknownDefaultCase|If 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.

**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.

**jersey2**: HTTP client: Jersey client 2.25.1. JSON processing: Jackson 2.9.x
**jersey3**: HTTP client: Jersey client 3.x. JSON processing: Jackson 2.x
**feign**: HTTP client: OpenFeign 10.x. JSON processing: Jackson 2.9.x. or Gson 2.x
**okhttp-gson**: [DEFAULT] HTTP client: OkHttp 3.x. JSON processing: Gson 2.8.x. Enable Parcelable models on Android using '-DparcelableModel=true'. Enable gzip request encoding using '-DuseGzipFeature=true'.
**retrofit2**: HTTP client: OkHttp 3.x. JSON processing: Gson 2.x (Retrofit 2.3.0). Enable the RxJava adapter using '-DuseRxJava[2/3]=true'. (RxJava 1.x or 2.x or 3.x)
**resttemplate**: HTTP client: Spring RestTemplate 4.x. JSON processing: Jackson 2.9.x
**webclient**: HTTP client: Spring WebClient 5.x. JSON processing: Jackson 2.9.x
**restclient**: HTTP client: Spring RestClient 6.1. JSON processing: Jackson 2.9.x
**resteasy**: HTTP client: Resteasy client 3.x. JSON processing: Jackson 2.9.x
**vertx**: HTTP client: VertX client 3.x. JSON processing: Jackson 2.9.x
**google-api-client**: HTTP client: Google API client 1.x. JSON processing: Jackson 2.9.x
**rest-assured**: HTTP client: rest-assured : 4.x. JSON processing: Gson 2.x or Jackson 2.10.x. Only for Java 8
**native**: HTTP client: Java native HttpClient. JSON processing: Jackson 2.9.x. Only for Java11+
**microprofile**: HTTP client: Microprofile client 1.x. JSON processing: JSON-B or Jackson 2.9.x
**apache-httpclient**: HTTP client: Apache httpclient 5.x

**jsonb**: Use JSON-B as serialization library
**jackson**: Use Jackson as serialization library
**gson**: Use Gson as serialization library

**true**: Use a SnapShot Version
**false**: Use a Release Version

|null| |sortModelPropertiesByRequiredFlag|Sort model properties to place required parameters before optional parameters.| |true| |sortParamsByRequiredFlag|Sort method arguments to place required parameters before optional parameters.| |true| |sourceFolder|source folder for generated code| |src/main/java| |supportStreaming|Support streaming endpoint (beta)| |false| |supportUrlQuery|Generate toUrlQueryString in POJO (default to true). Available on `native`, `apache-httpclient` libraries.| |false| |testOutput|Set output folder for models and APIs tests| |${project.build.directory}/generated-test-sources/openapi| |useAbstractionForFiles|Use alternative types instead of java.io.File to allow passing bytes without a file on disk. Available on resttemplate, webclient, restclient, libraries| |false| |useBeanValidation|Use BeanValidation API annotations| |false| |useEnumCaseInsensitive|Use `equalsIgnoreCase` when String for enum comparison| |false| |useGzipFeature|Send gzip-encoded requests| |false| |useJakartaEe|whether to use Jakarta EE namespace instead of javax| |false| |useOneOfDiscriminatorLookup|Use 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| |useOneOfInterfaces|whether to use a java interface to describe a set of oneOf options, where each option is a class that implements the interface| |false| |usePlayWS|Use Play! Async HTTP client (Play WS API)| |false| |useReflectionEqualsHashCode|Use 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| |useRuntimeException|Use RuntimeException instead of Exception. Only jersey2, jersey3, okhttp-gson, vertx, microprofile support this option.| |false| |useRxJava2|Whether to use the RxJava2 adapter with the retrofit2 library. IMPORTANT: This option has been deprecated.| |false| |useRxJava3|Whether to use the RxJava3 adapter with the retrofit2 library. IMPORTANT: This option has been deprecated.| |false| |useSingleRequestParameter|Setting 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 support this option.| |false| |webclientBlockingOperations|Making all WebClient operations blocking(sync). Note that if on operation 'x-webclient-blocking: false' then such operation won't be sync| |false| |withAWSV4Signature|whether to include AWS v4 signature support (only available for okhttp-gson library)| |false| |withXml|whether 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 name | Description | Applicable for | Default value | | -------------- | ----------- | -------------- | ------------- | |x-discriminator-value|Used with model inheritance to specify value for discriminator that identifies current model|MODEL| |x-implements|Ability to specify interfaces that model must implements|MODEL|empty array |x-setter-extra-annotation|Custom annotation that can be specified over java setter for specific field|FIELD|When field is array & uniqueItems, then this extension is used to add `@JsonDeserialize(as = LinkedHashSet.class)` over setter, otherwise no value |x-tags|Specify multiple swagger tags for operation|OPERATION|null |x-accepts|Specify custom value for 'Accept' header for operation|OPERATION|null |x-content-type|Specify custom value for 'Content-Type' header for operation|OPERATION|null |x-class-extra-annotation|List of custom annotations to be added to model|MODEL|null |x-field-extra-annotation|List of custom annotations to be added to property|FIELD|null |x-webclient-blocking|Specifies if method for specific operation should be blocking or non-blocking(ex: return `Mono/Flux` or `return T/List/Set` & execute `.block()` inside generated method)|OPERATION|false ## IMPORT MAPPING | Type/Alias | Imports | | ---------- | ------- | |Array|java.util.List| |ArrayList|java.util.ArrayList| |BigDecimal|java.math.BigDecimal| |Date|java.util.Date| |DateTime|org.joda.time.*| |File|java.io.File| |HashMap|java.util.HashMap| |LinkedHashSet|java.util.LinkedHashSet| |List|java.util.*| |LocalDate|org.joda.time.*| |LocalDateTime|org.joda.time.*| |LocalTime|org.joda.time.*| |Map|java.util.Map| |Set|java.util.*| |Timestamp|java.sql.Timestamp| |URI|java.net.URI| |UUID|java.util.UUID| ## INSTANTIATION TYPES | Type/Alias | Instantiated By | | ---------- | --------------- | |array|ArrayList| |map|HashMap| |set|LinkedHashSet| ## 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 | Name | Supported | Defined By | | ---- | --------- | ---------- | |BasePath|✓|ToolingExtension |Authorizations|✗|ToolingExtension |UserAgent|✗|ToolingExtension |MockServer|✗|ToolingExtension ### Data Type Feature | Name | Supported | Defined By | | ---- | --------- | ---------- | |Custom|✗|OAS2,OAS3 |Int32|✓|OAS2,OAS3 |Int64|✓|OAS2,OAS3 |Float|✓|OAS2,OAS3 |Double|✓|OAS2,OAS3 |Decimal|✓|ToolingExtension |String|✓|OAS2,OAS3 |Byte|✓|OAS2,OAS3 |Binary|✓|OAS2,OAS3 |Boolean|✓|OAS2,OAS3 |Date|✓|OAS2,OAS3 |DateTime|✓|OAS2,OAS3 |Password|✓|OAS2,OAS3 |File|✓|OAS2 |Uuid|✗| |Array|✓|OAS2,OAS3 |Null|✗|OAS3 |AnyType|✗|OAS2,OAS3 |Object|✓|OAS2,OAS3 |Maps|✓|ToolingExtension |CollectionFormat|✓|OAS2 |CollectionFormatMulti|✓|OAS2 |Enum|✓|OAS2,OAS3 |ArrayOfEnum|✓|ToolingExtension |ArrayOfModel|✓|ToolingExtension |ArrayOfCollectionOfPrimitives|✓|ToolingExtension |ArrayOfCollectionOfModel|✓|ToolingExtension |ArrayOfCollectionOfEnum|✓|ToolingExtension |MapOfEnum|✓|ToolingExtension |MapOfModel|✓|ToolingExtension |MapOfCollectionOfPrimitives|✓|ToolingExtension |MapOfCollectionOfModel|✓|ToolingExtension |MapOfCollectionOfEnum|✓|ToolingExtension ### Documentation Feature | Name | Supported | Defined By | | ---- | --------- | ---------- | |Readme|✓|ToolingExtension |Model|✓|ToolingExtension |Api|✓|ToolingExtension ### Global Feature | Name | Supported | Defined By | | ---- | --------- | ---------- | |Host|✓|OAS2,OAS3 |BasePath|✓|OAS2,OAS3 |Info|✓|OAS2,OAS3 |Schemes|✗|OAS2,OAS3 |PartialSchemes|✓|OAS2,OAS3 |Consumes|✓|OAS2 |Produces|✓|OAS2 |ExternalDocumentation|✓|OAS2,OAS3 |Examples|✓|OAS2,OAS3 |XMLStructureDefinitions|✗|OAS2,OAS3 |MultiServer|✗|OAS3 |ParameterizedServer|✓|OAS3 |ParameterStyling|✗|OAS3 |Callbacks|✗|OAS3 |LinkObjects|✗|OAS3 ### Parameter Feature | Name | Supported | Defined By | | ---- | --------- | ---------- | |Path|✓|OAS2,OAS3 |Query|✓|OAS2,OAS3 |Header|✓|OAS2,OAS3 |Body|✓|OAS2 |FormUnencoded|✓|OAS2 |FormMultipart|✓|OAS2 |Cookie|✓|OAS3 ### Schema Support Feature | Name | Supported | Defined By | | ---- | --------- | ---------- | |Simple|✓|OAS2,OAS3 |Composite|✓|OAS2,OAS3 |Polymorphism|✗|OAS2,OAS3 |Union|✗|OAS3 |allOf|✗|OAS2,OAS3 |anyOf|✗|OAS3 |oneOf|✗|OAS3 |not|✗|OAS3 ### Security Feature | Name | Supported | Defined By | | ---- | --------- | ---------- | |BasicAuth|✓|OAS2,OAS3 |ApiKey|✓|OAS2,OAS3 |OpenIDConnect|✗|OAS3 |BearerToken|✓|OAS3 |OAuth2_Implicit|✓|OAS2,OAS3 |OAuth2_Password|✓|OAS2,OAS3 |OAuth2_ClientCredentials|✓|OAS2,OAS3 |OAuth2_AuthorizationCode|✓|OAS2,OAS3 |SignatureAuth|✓|OAS3 |AWSV4Signature|✓|ToolingExtension ### Wire Format Feature | Name | Supported | Defined By | | ---- | --------- | ---------- | |JSON|✓|OAS2,OAS3 |XML|✓|OAS2,OAS3 |PROTOBUF|✗|ToolingExtension |Custom|✗|OAS2,OAS3