Class AbstractArgumentMethodArgumentResolver

java.lang.Object
org.springframework.shell.support.AbstractArgumentMethodArgumentResolver
All Implemented Interfaces:
org.springframework.messaging.handler.invocation.HandlerMethodArgumentResolver
Direct Known Subclasses:
ArgumentHeaderMethodArgumentResolver, ShellOptionMethodArgumentResolver

public abstract class AbstractArgumentMethodArgumentResolver extends Object implements org.springframework.messaging.handler.invocation.HandlerMethodArgumentResolver
Abstract base class to resolve method arguments from a named value, e.g. message headers or destination variables. Named values could have one or more of a name, a required flag, and a default value.

Subclasses only need to define specific steps such as how to obtain named value details from a method parameter, how to resolve to argument values, or how to handle missing values.

A default value string can contain ${...} placeholders and Spring Expression Language #{...} expressions which will be resolved if a ConfigurableBeanFactory is supplied to the class constructor.

A ConversionService is used to convert a resolved String argument value to the expected target method parameter type.

  • Field Details

  • Constructor Details

    • AbstractArgumentMethodArgumentResolver

      protected AbstractArgumentMethodArgumentResolver(org.springframework.core.convert.ConversionService conversionService, @Nullable org.springframework.beans.factory.config.ConfigurableBeanFactory beanFactory)
      Constructor with a ConversionService and a BeanFactory.
      Parameters:
      conversionService - conversion service for converting String values to the target method parameter type
      beanFactory - a bean factory for resolving ${...} placeholders and #{...} SpEL expressions in default values
  • Method Details

    • resolveArgument

      public Object resolveArgument(org.springframework.core.MethodParameter parameter, org.springframework.messaging.Message<?> message) throws Exception
      Specified by:
      resolveArgument in interface org.springframework.messaging.handler.invocation.HandlerMethodArgumentResolver
      Throws:
      Exception
    • createNamedValueInfo

      protected abstract AbstractArgumentMethodArgumentResolver.NamedValueInfo createNamedValueInfo(org.springframework.core.MethodParameter parameter)
      Create the AbstractArgumentMethodArgumentResolver.NamedValueInfo object for the given method parameter. Implementations typically retrieve the method annotation by means of MethodParameter.getParameterAnnotation(Class).
      Parameters:
      parameter - the method parameter
      Returns:
      the named value information
    • resolveArgumentInternal

      @Nullable protected abstract Object resolveArgumentInternal(org.springframework.core.MethodParameter parameter, org.springframework.messaging.Message<?> message, List<String> names) throws Exception
      Resolves the given parameter type and value name into an argument value.
      Parameters:
      parameter - the method parameter to resolve to an argument value
      message - the current request
      names - the name of the values being resolved
      Returns:
      the resolved argument. May be null
      Throws:
      Exception - in case of errors
    • handleMissingValue

      protected abstract void handleMissingValue(List<String> names, org.springframework.core.MethodParameter parameter, org.springframework.messaging.Message<?> message)
      Invoked when a value is required, but resolveArgumentInternal(org.springframework.core.MethodParameter, org.springframework.messaging.Message<?>, java.util.List<java.lang.String>) returned null and there is no default value. Sub-classes can throw an appropriate exception for this case.
      Parameters:
      names - the name for the value
      parameter - the target method parameter
      message - the message being processed
    • handleResolvedValue

      protected void handleResolvedValue(@Nullable Object arg, List<String> name, org.springframework.core.MethodParameter parameter, org.springframework.messaging.Message<?> message)
      Invoked after a value is resolved.
      Parameters:
      arg - the resolved argument value
      name - the argument name
      parameter - the argument parameter type
      message - the message