MapStruct

Since Camel 3.19

Only producer is supported

The camel-mapstruct component is used for converting POJOs using MapStruct.

URI format

mapstruct:className[?options]

Where className is the fully qualified class name of the POJO to convert to.

Configuring Options

Camel components are configured on two separate levels:

  • component level

  • endpoint level

Configuring Component Options

The component level is the highest level which holds general and common configurations that are inherited by the endpoints. For example a component may have security settings, credentials for authentication, urls for network connection and so forth.

Some components only have a few options, and others may have many. Because components typically have pre configured defaults that are commonly used, then you may often only need to configure a few options on a component; or none at all.

Configuring components can be done with the Component DSL, in a configuration file (application.properties|yaml), or directly with Java code.

Configuring Endpoint Options

Where you find yourself configuring the most is on endpoints, as endpoints often have many options, which allows you to configure what you need the endpoint to do. The options are also categorized into whether the endpoint is used as consumer (from) or as a producer (to), or used for both.

Configuring endpoints is most often done directly in the endpoint URI as path and query parameters. You can also use the Endpoint DSL and DataFormat DSL as a type safe way of configuring endpoints and data formats in Java.

A good practice when configuring options is to use Property Placeholders, which allows to not hardcode urls, port numbers, sensitive information, and other settings. In other words placeholders allows to externalize the configuration from your code, and gives more flexibility and reuse.

The following two sections lists all the options, firstly for the component followed by the endpoint.

Component Options

The MapStruct component supports 4 options, which are listed below.

Name Description Default Type

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

mapperPackageName (producer)

Required Package name(s) where Camel should discover Mapstruct mapping classes. Multiple package names can be separated by comma.

String

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

mapStructConverter (advanced)

Autowired To use a custom MapStructConverter such as adapting to a special runtime.

MapStructMapperFinder

Endpoint Options

The MapStruct endpoint is configured using URI syntax:

mapstruct:className

with the following path and query parameters:

Path Parameters (1 parameters)

Name Description Default Type

className (producer)

Required The fully qualified class name of the POJO that mapstruct should convert to (target).

String

Query Parameters (2 parameters)

Name Description Default Type

mandatory (producer)

Whether there must exist a mapstruct converter to convert to the POJO.

true

boolean

lazyStartProducer (producer (advanced))

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

Setting up MapStruct

The camel-mapstruct component must be configured with one or more package names, for classpath scanning MapStruct Mapper classes. This is needed because the Mapper classes are to be used for converting POJOs with MapStruct.

For example to set up two packages you can do as following:

MapstructComponent mc = context.getComponent("mapstruct", MapstructComponent.class);
mc.setMapperPackageName("com.foo.mapper,com.bar.mapper");

This can also be configured in application.properties:

camel.component.mapstruct.mapper-package-name = com.foo.mapper,com.bar.mapper

Camel will on startup scan these packages for classes which names ends with Mapper. These classes are then introspected to discover the mapping methods. These mapping methods are then registered into the Camel Type Converter registry. This means that you can also use type converter to convert the POJOs with MapStruct, such as:

from("direct:foo")
  .convertBodyTo(MyFooDto.class);

Where MyFooDto is a POJO that MapStruct is able to convert to/from.

Camel does not support mapper methods defined with a void return type such as those used with @MappingTarget.
If you define multiple mapping methods for the same from / to types, then the implementation chosen by Camel to do its type conversion is potentially non-deterministic.