ServiceLayer (Google Web Toolkit Javadoc)

java.lang.Object
- com.google.web.bindery.requestfactory.server.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 and Description

(package private) ServiceLayer top
A pointer to the top-most ServiceLayer instance.

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

Constructor Summary

Constructors
Constructor and Description

ServiceLayer()
Not generally-extensible.

Constructors
Constructor and Description
`ServiceLayer()` Not generally-extensible.

Method Summary

Methods
Modifier and Type	Method and 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

Class ServiceLayer

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

top

Constructor Detail

ServiceLayer

Method Detail

create

createDomainObject

createLocator

createServiceInstance

createServiceLocator

getDomainClassLoader

getGetter

getId

getIdType

getProperty

getRequestReturnType

getSetter

getVersion

invoke

isLive

loadDomainObject

loadDomainObjects

requiresServiceLocator

resolveClass

resolveClientType

resolveDomainClass

resolveDomainMethod

resolveLocator

resolveRequestContext

resolveRequestContextMethod

resolveRequestFactory

resolveServiceClass

resolveServiceLocator

resolveTypeToken

setProperty

validate