Class ServiceLayer
java.lang.Object
com.google.web.bindery.requestfactory.server.ServiceLayer
- Direct Known Subclasses:
ServiceLayerDecorator
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.
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Field Summary
Modifier and TypeFieldDescription(package private) ServiceLayer
A pointer to the top-most ServiceLayer instance. -
Constructor Summary
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Method Summary
Modifier and TypeMethodDescriptionstatic ServiceLayer
create
(ServiceLayerDecorator... decorators) Create a RequestFactory ServiceLayer that is optionally modified by the given decorators.abstract <T> T
createDomainObject
(Class<T> clazz) Create an instance of the requested domain type.abstract <T extends Locator<?,
?>>
TcreateLocator
(Class<T> clazz) Create an instance of the requestedLocator
type.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.abstract <T extends ServiceLocator>
TcreateServiceLocator
(Class<T> clazz) Create an instance of the requestedServiceLocator
type.abstract ClassLoader
Returns the ClassLoader that should be used when attempting to access domain classes or resources.abstract Method
Determine the method to invoke when retrieving the given property.abstract Object
Return the persistent id for a domain object.abstract Class<?>
Returns the type of object the domain type'sfindFoo()
orLocator.getId()
expects to receive.abstract Object
getProperty
(Object domainObject, String property) Retrieve the named property from the domain object.abstract Type
getRequestReturnType
(Method contextMethod) Compute the return type for a method declared in a RequestContext by analyzing the generic method declaration.abstract Method
Determine the method to invoke when setting the given property.abstract Object
getVersion
(Object domainObject) May returnnull
to indicate that the domain object has not been persisted.abstract Object
Invoke a domain service method.abstract boolean
Returnstrue
if the given domain object is still live (i.e.abstract <T> T
loadDomainObject
(Class<T> clazz, Object domainId) Load an object from the backing store.loadDomainObjects
(List<Class<?>> classes, List<Object> domainIds) Load multiple objects from the backing store.abstract boolean
requiresServiceLocator
(Method contextMethod, Method domainMethod) Determines if the invocation of a domain method requires aServiceLocator
as the 0th parameter when passed intoinvoke(Method, Object...)
.resolveClass
(String typeToken) Given a type token previously returned fromresolveTypeToken(Class)
, return the Class literal associated with the token.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.abstract Class<?>
resolveDomainClass
(Class<?> clientType) Determine the domain (server-side) type that the given client type is mapped to.abstract Method
resolveDomainMethod
(String operation) Return the domain service method associated with a RequestContext method declaration.resolveLocator
(Class<?> domainType) Return the type ofLocator
that should be used to access the given domain type.abstract Class<? extends RequestContext>
resolveRequestContext
(String operation) Find a RequestContext that should be used to fulfill the requested operation.abstract Method
resolveRequestContextMethod
(String operation) Find a RequestContext method declaration by name.abstract Class<? extends RequestFactory>
resolveRequestFactory
(String token) Loads and validates a RequestFactory interface.abstract Class<?>
resolveServiceClass
(Class<? extends RequestContext> requestContextClass) Given aRequestContext
method, find the service class referenced in theService
orServiceName
annotation.abstract Class<? extends ServiceLocator>
resolveServiceLocator
(Class<? extends RequestContext> requestContext) Given a RequestContext method declaration, resolve theServiceLocator
that should be used when invoking the domain method.abstract String
resolveTypeToken
(Class<? extends BaseProxy> proxyType) Return a string used to represent the given type in the wire protocol.abstract void
setProperty
(Object domainObject, String property, Class<?> expectedType, Object value) Sets a property on a domain object.abstract <T> Set<ConstraintViolation<T>>
validate
(T domainObject) Invoke a JSR 303 validator on the given domain object.
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Field Details
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top
ServiceLayer topA pointer to the top-most ServiceLayer instance.
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Constructor Details
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ServiceLayer
ServiceLayer()Not generally-extensible.
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Method Details
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create
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
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createDomainObject
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
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createLocator
Create an instance of the requestedLocator
type.- Type Parameters:
T
- the requested Locator type- Parameters:
clazz
- the requested Locator type- Returns:
- an instance of the requested Locator type
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createServiceInstance
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
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createServiceLocator
Create an instance of the requestedServiceLocator
type.- Type Parameters:
T
- the requested ServiceLocator type- Parameters:
clazz
- the requested ServiceLocator type- Returns:
- an instance of the requested ServiceLocator type
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getDomainClassLoader
Returns the ClassLoader that should be used when attempting to access domain classes or resources.The default implementation returns
Thread.currentThread().getContextClassLoader()
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getGetter
Determine the method to invoke when retrieving the given property.- Parameters:
domainType
- a domain entity typeproperty
- 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
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getId
Return the persistent id for a domain object. May returnnull
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
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getIdType
Returns the type of object the domain type'sfindFoo()
orLocator.getId()
expects to receive.- Parameters:
domainType
- a domain entity type- Returns:
- the type of the persistent id value used to represent the domain type
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getProperty
Retrieve the named property from the domain object.- Parameters:
domainObject
- the domain object being examinedproperty
- the property name- Returns:
- the value of the property
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getRequestReturnType
Compute the return type for a method declared in a RequestContext by analyzing the generic method declaration. -
getSetter
Determine the method to invoke when setting the given property.- Parameters:
domainType
- a domain entity typeproperty
- 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
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getVersion
May returnnull
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
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invoke
Invoke a domain service method. The underlying eventually callsMethod.invoke(Object, Object...)
.- Parameters:
domainMethod
- the method to invokeargs
- the arguments to pass to the method- Returns:
- the value returned from the method invocation
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isLive
Returnstrue
if the given domain object is still live (i.e. not deleted) in the backing store.- Parameters:
domainObject
- a domain entity- Returns:
true
ifdomainObject
could be retrieved at a later point in time
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loadDomainObject
Load an object from the backing store. This method may returnnull
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 loaddomainId
- an id previously returned fromgetId(Object)
- Returns:
- the requested object or
null
if it is irretrievable
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loadDomainObjects
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 loaddomainIds
- the ids previously returned fromgetId(Object)
- Returns:
- the requested objects, elements of which may be
null
if the requested objects were irretrievable
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requiresServiceLocator
Determines if the invocation of a domain method requires aServiceLocator
as the 0th parameter when passed intoinvoke(Method, Object...)
.- Parameters:
contextMethod
- a method defined in a RequestContextdomainMethod
- a domain method- Returns:
true
if a ServiceLocator is required
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resolveClass
Given a type token previously returned fromresolveTypeToken(Class)
, return the Class literal associated with the token.- Parameters:
typeToken
- a string token- Returns:
- the type represented by the token
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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, theclientType
parameter is used to ensure assignability.- Parameters:
domainClass
- the server-side type to be transported to the clientclientType
- the type to which the returned type must be assignablerequired
- iftrue
and no mapping is available, throw an exception, otherwise the method will returnnull
- Returns:
- a class that represents
domainClass
on the client which is assignable toclientType
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resolveDomainClass
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
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resolveDomainMethod
Return the domain service method associated with a RequestContext method declaration. TherequestContextMethod
will have been previously resolved by#resolveRequestContextMethod(String, String)
.- Parameters:
requestContext
- the RequestContext requested by the clientrequestContextMethod
- a RequestContext method declaration. Note that this Method may be defined in a supertype ofrequestContext
- Returns:
- the domain service method that should be invoked
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resolveLocator
Return the type ofLocator
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
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resolveRequestContext
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
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resolveRequestContextMethod
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
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resolveRequestFactory
Loads and validates a RequestFactory interface.- Parameters:
token
- the RequestFactory's type token (usually the type's binary name)- Returns:
- the RequestFactory type
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resolveServiceClass
Given aRequestContext
method, find the service class referenced in theService
orServiceName
annotation.- Parameters:
requestContextClass
- a RequestContext interface- Returns:
- the type of service to use
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resolveServiceLocator
public abstract Class<? extends ServiceLocator> resolveServiceLocator(Class<? extends RequestContext> requestContext) Given a RequestContext method declaration, resolve theServiceLocator
that should be used when invoking the domain method. This method will only be called ifrequiresServiceLocator(Method, Method)
returnedtrue
for the associated domain method.- Parameters:
requestContext
- the RequestContext for which a ServiceLocator must be located- Returns:
- the type of ServiceLocator to use
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resolveTypeToken
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
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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 onproperty
- the name of the property to setexpectedType
- the type of the propertyvalue
- the new value
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validate
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
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