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

Class ServiceLayer

  • Direct Known Subclasses:
    ServiceLayerDecorator
    public abstract class ServiceLayer
extends java.lang.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 Summary

      Fields 
      Modifier and Type Field Description
      (package private) ServiceLayer top
      A pointer to the top-most ServiceLayer instance.

    • Constructor Summary

      Constructors 
      Constructor Description
      ServiceLayer()
      Not generally-extensible.

    • Method Summary

      All Methods Static Methods Instance Methods Abstract Methods Concrete Methods 
      Modifier and Type Method Description
      static ServiceLayer create​(ServiceLayerDecorator... decorators)
      Create a RequestFactory ServiceLayer that is optionally modified by the given decorators.
      abstract <T> T createDomainObject​(java.lang.Class<T> clazz)
      Create an instance of the requested domain type.
      abstract <T extends Locator<?,​?>>
      T      		 createLocator​(java.lang.Class<T> clazz)
      Create an instance of the requested Locator type.
      abstract java.lang.Object createServiceInstance​(java.lang.Class<? extends RequestContext> requestContext)
      Create an instance of a service object that can be used as the target for the given method invocation.
      abstract <T extends ServiceLocator>
      T      		 createServiceLocator​(java.lang.Class<T> clazz)
      Create an instance of the requested ServiceLocator type.
      abstract java.lang.ClassLoader getDomainClassLoader()
      Returns the ClassLoader that should be used when attempting to access domain classes or resources.
      abstract java.lang.reflect.Method getGetter​(java.lang.Class<?> domainType, java.lang.String property)
      Determine the method to invoke when retrieving the given property.
      abstract java.lang.Object getId​(java.lang.Object domainObject)
      Return the persistent id for a domain object.
      abstract java.lang.Class<?> getIdType​(java.lang.Class<?> domainType)
      Returns the type of object the domain type's findFoo() or Locator.getId() expects to receive.
      abstract java.lang.Object getProperty​(java.lang.Object domainObject, java.lang.String property)
      Retrieve the named property from the domain object.
      abstract java.lang.reflect.Type getRequestReturnType​(java.lang.reflect.Method contextMethod)
      Compute the return type for a method declared in a RequestContext by analyzing the generic method declaration.
      abstract java.lang.reflect.Method getSetter​(java.lang.Class<?> domainType, java.lang.String property)
      Determine the method to invoke when setting the given property.
      abstract java.lang.Object getVersion​(java.lang.Object domainObject)
      May return null to indicate that the domain object has not been persisted.
      abstract java.lang.Object invoke​(java.lang.reflect.Method domainMethod, java.lang.Object... args)
      Invoke a domain service method.
      abstract boolean isLive​(java.lang.Object domainObject)
      Returns true if the given domain object is still live (i.e.
      abstract <T> T loadDomainObject​(java.lang.Class<T> clazz, java.lang.Object domainId)
      Load an object from the backing store.
      abstract java.util.List<java.lang.Object> loadDomainObjects​(java.util.List<java.lang.Class<?>> classes, java.util.List<java.lang.Object> domainIds)
      Load multiple objects from the backing store.
      abstract boolean requiresServiceLocator​(java.lang.reflect.Method contextMethod, java.lang.reflect.Method domainMethod)
      Determines if the invocation of a domain method requires a ServiceLocator as the 0th parameter when passed into invoke(Method, Object...).
      abstract java.lang.Class<? extends BaseProxy> resolveClass​(java.lang.String typeToken)
      Given a type token previously returned from resolveTypeToken(Class), return the Class literal associated with the token.
      abstract <T> java.lang.Class<? extends T> resolveClientType​(java.lang.Class<?> domainClass, java.lang.Class<T> clientType, boolean required)
      Determine the type used by the client code to represent a given domain type.
      abstract java.lang.Class<?> resolveDomainClass​(java.lang.Class<?> clientType)
      Determine the domain (server-side) type that the given client type is mapped to.
      abstract java.lang.reflect.Method resolveDomainMethod​(java.lang.String operation)
      Return the domain service method associated with a RequestContext method declaration.
      abstract java.lang.Class<? extends Locator<?,​?>> resolveLocator​(java.lang.Class<?> domainType)
      Return the type of Locator that should be used to access the given domain type.
      abstract java.lang.Class<? extends RequestContext> resolveRequestContext​(java.lang.String operation)
      Find a RequestContext that should be used to fulfill the requested operation.
      abstract java.lang.reflect.Method resolveRequestContextMethod​(java.lang.String operation)
      Find a RequestContext method declaration by name.
      abstract java.lang.Class<? extends RequestFactory> resolveRequestFactory​(java.lang.String token)
      Loads and validates a RequestFactory interface.
      abstract java.lang.Class<?> resolveServiceClass​(java.lang.Class<? extends RequestContext> requestContextClass)
      Given a RequestContext method, find the service class referenced in the Service or ServiceName annotation.
      abstract java.lang.Class<? extends ServiceLocator> resolveServiceLocator​(java.lang.Class<? extends RequestContext> requestContext)
      Given a RequestContext method declaration, resolve the ServiceLocator that should be used when invoking the domain method.
      abstract java.lang.String resolveTypeToken​(java.lang.Class<? extends BaseProxy> proxyType)
      Return a string used to represent the given type in the wire protocol.
      abstract void setProperty​(java.lang.Object domainObject, java.lang.String property, java.lang.Class<?> expectedType, java.lang.Object value)
      Sets a property on a domain object.
      abstract <T> java.util.Set<ConstraintViolation<T>> validate​(T domainObject)
      Invoke a JSR 303 validator on the given domain object.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Field Detail

      • top

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

    • Constructor Detail

      • ServiceLayer

        ServiceLayer()
        Not generally-extensible.

    • Method Detail

      • 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​(java.lang.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​(java.lang.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 java.lang.Object createServiceInstance​(java.lang.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​(java.lang.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 java.lang.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 java.lang.reflect.Method getGetter​(java.lang.Class<?> domainType,
                                                   java.lang.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 java.lang.Object getId​(java.lang.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 java.lang.Class<?> getIdType​(java.lang.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 java.lang.Object getProperty​(java.lang.Object domainObject,
                                             java.lang.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 java.lang.reflect.Type getRequestReturnType​(java.lang.reflect.Method contextMethod)
        Compute the return type for a method declared in a RequestContext by analyzing the generic method declaration.

      • getSetter

        public abstract java.lang.reflect.Method getSetter​(java.lang.Class<?> domainType,
                                                   java.lang.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 java.lang.Object getVersion​(java.lang.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 java.lang.Object invoke​(java.lang.reflect.Method domainMethod,
                                        java.lang.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​(java.lang.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​(java.lang.Class<T> clazz,
                                       java.lang.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 java.util.List<java.lang.Object> loadDomainObjects​(java.util.List<java.lang.Class<?>> classes,
                                                                   java.util.List<java.lang.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​(java.lang.reflect.Method contextMethod,
                                               java.lang.reflect.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 java.lang.Class<? extends BaseProxy> resolveClass​(java.lang.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> java.lang.Class<? extends T> resolveClientType​(java.lang.Class<?> domainClass,
                                                                   java.lang.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 java.lang.Class<?> resolveDomainClass​(java.lang.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 java.lang.reflect.Method resolveDomainMethod​(java.lang.String operation)
        Return the domain service method associated with a RequestContext method declaration. The requestContextMethod will have been previously resolved by #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 java.lang.Class<? extends Locator<?,​?>> resolveLocator​(java.lang.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 java.lang.Class<? extends RequestContext> resolveRequestContext​(java.lang.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 java.lang.reflect.Method resolveRequestContextMethod​(java.lang.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 java.lang.Class<? extends RequestFactory> resolveRequestFactory​(java.lang.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 java.lang.Class<?> resolveServiceClass​(java.lang.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 java.lang.Class<? extends ServiceLocator> resolveServiceLocator​(java.lang.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 java.lang.String resolveTypeToken​(java.lang.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​(java.lang.Object domainObject,
                                 java.lang.String property,
                                 java.lang.Class<?> expectedType,
                                 java.lang.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> java.util.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