Package com.google.web.bindery.requestfactory.server

Class ServiceLayer

java.lang.Object
com.google.web.bindery.requestfactory.server.ServiceLayer
Direct Known Subclasses:
ServiceLayerDecorator
public abstract class ServiceLayer extends Object
The ServiceLayer mediates all interactions between the SimpleRequestProcessor and the domain environment. The core service logic can be decorated by extending an ServiceLayerDecorator.

This API is subject to change in future releases.

  • Field Details

    • top

      ServiceLayer top
      A pointer to the top-most ServiceLayer instance.

  • Constructor Details

    • ServiceLayer

      ServiceLayer()
      Not generally-extensible.

  • Method Details

    • create

      public static ServiceLayer create(ServiceLayerDecorator... decorators)
      Create a RequestFactory ServiceLayer that is optionally modified by the given decorators.
      Parameters:
      decorators - the decorators that will modify the behavior of the core service layer implementation
      Returns:
      a ServiceLayer instance

    • createDomainObject

      public abstract <T> T createDomainObject(Class<T> clazz)
      Create an instance of the requested domain type.
      Type Parameters:
      T - the requested domain type
      Parameters:
      clazz - the requested domain type
      Returns:
      an instance of the requested domain type

    • createLocator

      public abstract <T extends Locator<?, ?>> T createLocator(Class<T> clazz)
      Create an instance of the requested Locator type.
      Type Parameters:
      T - the requested Locator type
      Parameters:
      clazz - the requested Locator type
      Returns:
      an instance of the requested Locator type

    • createServiceInstance

      public abstract Object createServiceInstance(Class<? extends RequestContext> requestContext)
      Create an instance of a service object that can be used as the target for the given method invocation.
      Parameters:
      requestContext - the RequestContext type for which a service object must be instantiated.
      Returns:
      an instance of the requested service object

    • createServiceLocator

      public abstract <T extends ServiceLocator> T createServiceLocator(Class<T> clazz)
      Create an instance of the requested ServiceLocator type.
      Type Parameters:
      T - the requested ServiceLocator type
      Parameters:
      clazz - the requested ServiceLocator type
      Returns:
      an instance of the requested ServiceLocator type

    • getDomainClassLoader

      public abstract ClassLoader getDomainClassLoader()
      Returns the ClassLoader that should be used when attempting to access domain classes or resources.

      The default implementation returns Thread.currentThread().getContextClassLoader().

    • getGetter

      public abstract Method getGetter(Class<?> domainType, String property)
      Determine the method to invoke when retrieving the given property.
      Parameters:
      domainType - a domain entity type
      property - the name of the property to be retrieved
      Returns:
      the Method that should be invoked to retrieve the property or null if the method could not be located

    • getId

      public abstract Object getId(Object domainObject)
      Return the persistent id for a domain object. May return null to indicate that the domain object has not been persisted. The value returned from this method must be a simple type (e.g. Integer, String) or a domain type for which a mapping to an EntityProxy or Value proxy exists.

      The values returned from this method may be passed to loadDomainObject(Class, Object) in the future.

      Parameters:
      domainObject - a domain object
      Returns:
      the persistent id of the domain object or null if the object is not persistent

    • getIdType

      public abstract Class<?> getIdType(Class<?> domainType)
      Returns the type of object the domain type's findFoo() or Locator.getId() expects to receive.
      Parameters:
      domainType - a domain entity type
      Returns:
      the type of the persistent id value used to represent the domain type

    • getProperty

      public abstract Object getProperty(Object domainObject, String property)
      Retrieve the named property from the domain object.
      Parameters:
      domainObject - the domain object being examined
      property - the property name
      Returns:
      the value of the property

    • getRequestReturnType

      public abstract Type getRequestReturnType(Method contextMethod)
      Compute the return type for a method declared in a RequestContext by analyzing the generic method declaration.

    • getSetter

      public abstract Method getSetter(Class<?> domainType, String property)
      Determine the method to invoke when setting the given property.
      Parameters:
      domainType - a domain entity type
      property - the name of the property to be set
      Returns:
      the Method that should be invoked to set the property or null if the method could not be located

    • getVersion

      public abstract Object getVersion(Object domainObject)
      May return null to indicate that the domain object has not been persisted. The value returned from this method must be a simple type (e.g. Integer, String) or a domain type for which a mapping to an EntityProxy or Value proxy exists.
      Parameters:
      domainObject - a domain object
      Returns:
      the version of the domain object or null if the object is not persistent

    • invoke

      public abstract Object invoke(Method domainMethod, Object... args)
      Invoke a domain service method. The underlying eventually calls Method.invoke(Object, Object...).
      Parameters:
      domainMethod - the method to invoke
      args - the arguments to pass to the method
      Returns:
      the value returned from the method invocation

    • isLive

      public abstract boolean isLive(Object domainObject)
      Returns true if the given domain object is still live (i.e. not deleted) in the backing store.
      Parameters:
      domainObject - a domain entity
      Returns:
      true if domainObject could be retrieved at a later point in time

    • loadDomainObject

      public abstract <T> T loadDomainObject(Class<T> clazz, Object domainId)
      Load an object from the backing store. This method may return null to indicate that the requested object is no longer available.
      Type Parameters:
      T - the type of object to load
      Parameters:
      clazz - the type of object to load
      domainId - an id previously returned from getId(Object)
      Returns:
      the requested object or null if it is irretrievable

    • loadDomainObjects

      public abstract List<Object> loadDomainObjects(List<Class<?>> classes, List<Object> domainIds)
      Load multiple objects from the backing store. This method is intended to allow more efficient access to the backing store by providing all objects referenced in an incoming payload.

      The default implementation of this method will delegate to loadDomainObject(Class, Object).

      Parameters:
      classes - type type of each object to load
      domainIds - the ids previously returned from getId(Object)
      Returns:
      the requested objects, elements of which may be null if the requested objects were irretrievable

    • requiresServiceLocator

      public abstract boolean requiresServiceLocator(Method contextMethod, Method domainMethod)
      Determines if the invocation of a domain method requires a ServiceLocator as the 0th parameter when passed into invoke(Method, Object...).
      Parameters:
      contextMethod - a method defined in a RequestContext
      domainMethod - a domain method
      Returns:
      true if a ServiceLocator is required

    • resolveClass

      public abstract Class<? extends BaseProxy> resolveClass(String typeToken)
      Given a type token previously returned from resolveTypeToken(Class), return the Class literal associated with the token.
      Parameters:
      typeToken - a string token
      Returns:
      the type represented by the token

    • resolveClientType

      public abstract <T> Class<? extends T> resolveClientType(Class<?> domainClass, Class<T> clientType, boolean required)
      Determine the type used by the client code to represent a given domain type. If multiple proxy types have been mapped to the same domain type, the clientType parameter is used to ensure assignability.
      Parameters:
      domainClass - the server-side type to be transported to the client
      clientType - the type to which the returned type must be assignable
      required - if true and no mapping is available, throw an exception, otherwise the method will return null
      Returns:
      a class that represents domainClass on the client which is assignable to clientType

    • resolveDomainClass

      public abstract Class<?> resolveDomainClass(Class<?> clientType)
      Determine the domain (server-side) type that the given client type is mapped to.
      Parameters:
      clientType - a client-side type
      Returns:
      the domain type that clientType represents

    • resolveDomainMethod

      public abstract Method resolveDomainMethod(String operation)
      Return the domain service method associated with a RequestContext method declaration. The requestContextMethod will have been previously resolved by
      invalid reference 
      #resolveRequestContextMethod(String, String)
      .
      Parameters:
      requestContext - the RequestContext requested by the client
      requestContextMethod - a RequestContext method declaration. Note that this Method may be defined in a supertype of requestContext
      Returns:
      the domain service method that should be invoked

    • resolveLocator

      public abstract Class<? extends Locator<?,?>> resolveLocator(Class<?> domainType)
      Return the type of Locator that should be used to access the given domain type.
      Parameters:
      domainType - a domain (server-side) type
      Returns:
      the type of Locator to use, or null if the type conforms to the RequestFactory entity protocol

    • resolveRequestContext

      public abstract Class<? extends RequestContext> resolveRequestContext(String operation)
      Find a RequestContext that should be used to fulfill the requested operation.
      Parameters:
      operation - the operation
      Returns:
      the RequestContext or null if no RequestContext exists that can fulfill the operation

    • resolveRequestContextMethod

      public abstract Method resolveRequestContextMethod(String operation)
      Find a RequestContext method declaration by name.
      Parameters:
      operation - the operation's name
      Returns:
      the method declaration, or null if the method does not exist

    • resolveRequestFactory

      public abstract Class<? extends RequestFactory> resolveRequestFactory(String token)
      Loads and validates a RequestFactory interface.
      Parameters:
      token - the RequestFactory's type token (usually the type's binary name)
      Returns:
      the RequestFactory type

    • resolveServiceClass

      public abstract Class<?> resolveServiceClass(Class<? extends RequestContext> requestContextClass)
      Given a RequestContext method, find the service class referenced in the Service or ServiceName annotation.
      Parameters:
      requestContextClass - a RequestContext interface
      Returns:
      the type of service to use

    • resolveServiceLocator

      public abstract Class<? extends ServiceLocator> resolveServiceLocator(Class<? extends RequestContext> requestContext)
      Given a RequestContext method declaration, resolve the ServiceLocator that should be used when invoking the domain method. This method will only be called if requiresServiceLocator(Method, Method) returned true for the associated domain method.
      Parameters:
      requestContext - the RequestContext for which a ServiceLocator must be located
      Returns:
      the type of ServiceLocator to use

    • resolveTypeToken

      public abstract String resolveTypeToken(Class<? extends BaseProxy> proxyType)
      Return a string used to represent the given type in the wire protocol.
      Parameters:
      proxyType - a client-side EntityProxy or ValueProxy type
      Returns:
      the type token used to represent the proxy type

    • setProperty

      public abstract void setProperty(Object domainObject, String property, Class<?> expectedType, Object value)
      Sets a property on a domain object.
      Parameters:
      domainObject - the domain object to operate on
      property - the name of the property to set
      expectedType - the type of the property
      value - the new value

    • validate

      public abstract <T> Set<ConstraintViolation<T>> validate(T domainObject)
      Invoke a JSR 303 validator on the given domain object. If no validator is available, this method is a no-op.
      Type Parameters:
      T - the type of data being validated
      Parameters:
      domainObject - the domain objcet to validate
      Returns:
      the violations associated with the domain object