55.4. Nullable Options
Overview
In some cases, it can make sense to let method arguments default to
null. But this is not allowed by default. If you want to allow some of your method arguments from the Java API to take null values, you must declare this explicitly using the nullableOptions element.
Syntax
The
nullableOptions element can be defined with one or more nullableOption child elements, as follows:
<nullableOptions> <nullableOption>ArgumentName</nullableOption> ... </nullableOptions>
Where
ArgumentName is the name of a method argument from the Java API.
Scope
As shown in the following extract, the
nullableOptions element can optionally appear as a child of the apis element and/or as a child of api elements:
<configuration>
<apis>
<api>
<apiName>...</apiName>
...
<nullableOptions>...</nullableOptions>
</api>
...
<nullableOptions>...</nullableOptions>
</apis>
</configuration>
You can define the
nullableOptions element at the following scopes:
- As a child of an
apielement—thenullableOptionsmappings apply only to the API class specified by theapielement. - As a child of the
apiselement—thenullableOptionsmappings apply to all API classes by default, but can be overridden at theapilevel.
Example
The following example shows the nullable options declared for the
CompaniesResource proxy class from the Apache Camel LinkedIn component:
<nullableOptions> <nullableOption>companySizes</nullableOption> <nullableOption>count</nullableOption> <nullableOption>email_domain</nullableOption> <nullableOption>end_timestamp</nullableOption> <nullableOption>event_type</nullableOption> <nullableOption>geos</nullableOption> <nullableOption>industries</nullableOption> <nullableOption>is_company_admin</nullableOption> <nullableOption>jobFunc</nullableOption> <nullableOption>secure_urls</nullableOption> <nullableOption>seniorities</nullableOption> <nullableOption>start</nullableOption> <nullableOption>start_timestamp</nullableOption> <nullableOption>statistics_update_key</nullableOption> <nullableOption>time_granularity</nullableOption> </nullableOptions>
