REST Swagger
Since Camel 2.19
Only producer is supported
The REST Swagger* configures rest producers from Swagger (Open API) specification document and delegates to a component implementing the RestProducerFactory interface. Currently known working components are:
Maven users will need to add the following dependency to their
pom.xml
for this component:
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-rest-swagger</artifactId>
<version>x.x.x</version>
<!-- use the same version as your Camel core version -->
</dependency>
URI format
rest-swagger:[specificationPath#]operationId
Where operationId
is the ID of the operation in the Swagger
specification, and specificationPath
is the path to the
specification.
If the specificationPath
is not specified it defaults to
swagger.json
. The lookup mechanism uses Camels ResourceHelper
to
load the resource, which means that you can use CLASSPATH resources
(classpath:my-specification.json
), files
(file:/some/path.json
), the web
(http://api.example.com/swagger.json
) or reference a bean
(ref:nameOfBean
) or use a method of a bean
(bean:nameOfBean.methodName
) to get the specification resource,
failing that Swagger’s own resource loading support.
This component does not act as a HTTP client, it delegates that to
another component mentioned above. The lookup mechanism searches for a
single component that implements the RestProducerFactory interface and
uses that. If the CLASSPATH contains more than one, then the property
componentName
should be set to indicate which component to delegate
to.
Most of the configuration is taken from the Swagger specification but
the option exists to override those by specifying them on the component
or on the endpoint. Typically you would just need to override the
host
or basePath
if those differ from the specification.
The |
With componentName
you specify what component is used to perform the
requests, this named component needs to be present in the Camel context
and implement the required RestProducerFactory interface — as do the
components listed at the top.
If you do not specify the componentName at either component or endpoint level, CLASSPATH is searched for a suitable delegate. There should be only one component present on the CLASSPATH that implements the RestProducerFactory interface for this to work.
This component’s endpoint URI is lenient which means that in addition
to message headers you can specify REST operation’s parameters as
endpoint parameters, these will be constant for all subsequent
invocations so it makes sense to use this feature only for parameters
that are indeed constant for all invocations — for example API version
in path such as /api/{version}/users/{id}
.
Options
The REST Swagger component supports 10 options, which are listed below.
Name | Description | Default | Type |
---|---|---|---|
basePath (producer) |
API basePath, for example /v2. Default is unset, if set overrides the value present in Swagger specification. |
String |
|
componentName (producer) |
Name of the Camel component that will perform the requests. The component must be present in Camel registry and it must implement RestProducerFactory service provider interface. If not set CLASSPATH is searched for single component that implements RestProducerFactory SPI. Can be overridden in endpoint configuration. |
String |
|
consumes (producer) |
What payload type this component capable of consuming. Could be one type, like application/json or multiple types as application/json, application/xml; q=0.5 according to the RFC7231. This equates to the value of Accept HTTP header. If set overrides any value found in the Swagger specification. Can be overridden in endpoint configuration |
String |
|
host (producer) |
Scheme hostname and port to direct the HTTP requests to in the form of https://hostname:port. Can be configured at the endpoint, component or in the corresponding REST configuration in the Camel Context. If you give this component a name (e.g. petstore) that REST configuration is consulted first, rest-swagger next, and global configuration last. If set overrides any value found in the Swagger specification, RestConfiguration. Can be overridden in endpoint configuration. |
String |
|
lazyStartProducer (producer) |
Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing. |
false |
boolean |
produces (producer) |
What payload type this component is producing. For example application/json according to the RFC7231. This equates to the value of Content-Type HTTP header. If set overrides any value present in the Swagger specification. Can be overridden in endpoint configuration. |
String |
|
specificationUri (producer) |
Path to the Swagger specification file. The scheme, host base path are taken from this specification, but these can be overridden with properties on the component or endpoint level. If not given the component tries to load swagger.json resource. Note that the host defined on the component and endpoint of this Component should contain the scheme, hostname and optionally the port in the URI syntax (i.e. https://api.example.com:8080). Can be overridden in endpoint configuration. |
swagger.json |
URI |
autowiredEnabled (advanced) |
Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc. |
true |
boolean |
sslContextParameters (security) |
Customize TLS parameters used by the component. If not set defaults to the TLS parameters set in the Camel context |
SSLContextParameters |
|
useGlobalSslContextParameters (security) |
Enable usage of global SSL context parameters. |
false |
boolean |
The REST Swagger endpoint is configured using URI syntax:
rest-swagger:specificationUri#operationId
with the following path and query parameters:
Path Parameters (2 parameters):
Name | Description | Default | Type |
---|---|---|---|
specificationUri |
Path to the Swagger specification file. The scheme, host base path are taken from this specification, but these can be overridden with properties on the component or endpoint level. If not given the component tries to load swagger.json resource from the classpath. Note that the host defined on the component and endpoint of this Component should contain the scheme, hostname and optionally the port in the URI syntax (i.e. http://api.example.com:8080). Overrides component configuration. The Swagger specification can be loaded from different sources by prefixing with file: classpath: http: https:. Support for https is limited to using the JDK installed UrlHandler, and as such it can be cumbersome to setup TLS/SSL certificates for https (such as setting a number of javax.net.ssl JVM system properties). How to do that consult the JDK documentation for UrlHandler. Default value notice: By default loads swagger.json file |
swagger.json |
URI |
operationId |
Required ID of the operation from the Swagger specification. |
String |
Query Parameters (8 parameters):
Name | Description | Default | Type |
---|---|---|---|
basePath (producer) |
API basePath, for example /v2. Default is unset, if set overrides the value present in Swagger specification and in the component configuration. |
String |
|
componentName (producer) |
Name of the Camel component that will perform the requests. The component must be present in Camel registry and it must implement RestProducerFactory service provider interface. If not set CLASSPATH is searched for single component that implements RestProducerFactory SPI. Overrides component configuration. |
String |
|
consumes (producer) |
What payload type this component capable of consuming. Could be one type, like application/json or multiple types as application/json, application/xml; q=0.5 according to the RFC7231. This equates to the value of Accept HTTP header. If set overrides any value found in the Swagger specification and. in the component configuration |
String |
|
host (producer) |
Scheme hostname and port to direct the HTTP requests to in the form of https://hostname:port. Can be configured at the endpoint, component or in the corresponding REST configuration in the Camel Context. If you give this component a name (e.g. petstore) that REST configuration is consulted first, rest-swagger next, and global configuration last. If set overrides any value found in the Swagger specification, RestConfiguration. Overrides all other configuration. |
String |
|
lazyStartProducer (producer) |
Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing. |
false |
boolean |
produces (producer) |
What payload type this component is producing. For example application/json according to the RFC7231. This equates to the value of Content-Type HTTP header. If set overrides any value present in the Swagger specification. Overrides all other configuration. |
String |
|
synchronous (advanced) |
Sets whether synchronous processing should be strictly used, or Camel is allowed to use asynchronous processing (if supported). |
false |
boolean |
sslContextParameters (security) |
To configure security using SSLContextParameters. |
SSLContextParameters |
Example: PetStore
Checkout the example in the camel-example-rest-swagger
project in
the examples
directory.
For example if you wanted to use the
PetStore provided REST API simply
reference the specification URI and desired operation id from the
Swagger specification or download the specification and store it as
swagger.json
(in the root) of CLASSPATH that way it will be
automaticaly used. Let’s use the Undertow
component to perform all the requests and Camels excelent support for
Spring Boot.
Here are our dependencies defined in Maven POM file:
<dependency>
<groupId>org.apache.camel.springboot</groupId>
<artifactId>camel-undertow-starter</artifactId>
</dependency>
<dependency>
<groupId>org.apache.camel.springboot</groupId>
<artifactId>camel-rest-swagger-starter</artifactId>
</dependency>
Start by defining the Undertow component and the RestSwaggerComponent:
@Bean
public Component petstore(CamelContext camelContext, UndertowComponent undertow) {
RestSwaggerComponent petstore = new RestSwaggerComponent(camelContext);
petstore.setSpecificationUri("http://petstore.swagger.io/v2/swagger.json");
petstore.setDelegate(undertow);
return petstore;
}
Support in Camel for Spring Boot will auto create the
|
Now in our application we can simply use the ProducerTemplate
to
invoke PetStore REST methods:
@Autowired
ProducerTemplate template;
String getPetJsonById(int petId) {
return template.requestBodyAndHeaders("petstore:getPetById", null, "petId", petId);
}
Spring Boot Auto-Configuration
When using rest-swagger with Spring Boot make sure to use the following Maven dependency to have support for auto configuration:
<dependency>
<groupId>org.apache.camel.springboot</groupId>
<artifactId>camel-rest-swagger-starter</artifactId>
<version>x.x.x</version>
<!-- use the same version as your Camel core version -->
</dependency>
The component supports 11 options, which are listed below.
Name | Description | Default | Type |
---|---|---|---|
camel.component.rest-swagger.autowired-enabled |
Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc. |
true |
Boolean |
camel.component.rest-swagger.base-path |
API basePath, for example /v2. Default is unset, if set overrides the value present in Swagger specification. |
String |
|
camel.component.rest-swagger.component-name |
Name of the Camel component that will perform the requests. The component must be present in Camel registry and it must implement RestProducerFactory service provider interface. If not set CLASSPATH is searched for single component that implements RestProducerFactory SPI. Can be overridden in endpoint configuration. |
String |
|
camel.component.rest-swagger.consumes |
What payload type this component capable of consuming. Could be one type, like application/json or multiple types as application/json, application/xml; q=0.5 according to the RFC7231. This equates to the value of Accept HTTP header. If set overrides any value found in the Swagger specification. Can be overridden in endpoint configuration |
String |
|
camel.component.rest-swagger.enabled |
Whether to enable auto configuration of the rest-swagger component. This is enabled by default. |
Boolean |
|
camel.component.rest-swagger.host |
Scheme hostname and port to direct the HTTP requests to in the form of https://hostname:port. Can be configured at the endpoint, component or in the corresponding REST configuration in the Camel Context. If you give this component a name (e.g. petstore) that REST configuration is consulted first, rest-swagger next, and global configuration last. If set overrides any value found in the Swagger specification, RestConfiguration. Can be overridden in endpoint configuration. |
String |
|
camel.component.rest-swagger.lazy-start-producer |
Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing. |
false |
Boolean |
camel.component.rest-swagger.produces |
What payload type this component is producing. For example application/json according to the RFC7231. This equates to the value of Content-Type HTTP header. If set overrides any value present in the Swagger specification. Can be overridden in endpoint configuration. |
String |
|
camel.component.rest-swagger.specification-uri |
Path to the Swagger specification file. The scheme, host base path are taken from this specification, but these can be overridden with properties on the component or endpoint level. If not given the component tries to load swagger.json resource. Note that the host defined on the component and endpoint of this Component should contain the scheme, hostname and optionally the port in the URI syntax (i.e. https://api.example.com:8080). Can be overridden in endpoint configuration. |
URI |
|
camel.component.rest-swagger.ssl-context-parameters |
Customize TLS parameters used by the component. If not set defaults to the TLS parameters set in the Camel context. The option is a org.apache.camel.support.jsse.SSLContextParameters type. |
SSLContextParameters |
|
camel.component.rest-swagger.use-global-ssl-context-parameters |
Enable usage of global SSL context parameters. |
false |
Boolean |