org.apache.uima.resource

Interface ResourceManager

All Known Subinterfaces:

ResourceManagerPearWrapper

public interface ResourceManager

A ResourceManager holds a collection of Resource objects, each registered under a specified key.

Method Summary

Modifier and Type	Method and Description
void	destroy() Frees all resources held by this ResourceManager, and marks the ResourceManager as having been destroyed.
CasManager	getCasManager() Gets the CasManager, which manages the creation and pooling of CASes.
String	getDataPath() Gets the data path used to resolve relative paths.
ClassLoader	getExtensionClassLoader() Returns the UIMA extension class loader.
List<Object>	getExternalResources()
Map<String,XMLizable>	getImportCache() Deprecated. Intended just for internal use.
Object	getResource(String aName) Gets the instance of the implementation object for a resource that has been registered under the specified name.
Object	getResource(String aName, String[] aParams) Returns one of two kinds of objects (or null): - an instance of the implementation object for a resource, that has been loaded with a DataResource resource produced by the resource given the aParms - (if there is no implementation defined for this resource) returns an instance of the DataResource, itself, produced by the resource given the aParms An example of a parameterized Resource is a dictionary whose data depend on a specified language identifier.
InputStream	getResourceAsStream(String aKey) Retrieves an InputStream for reading from the named resource.
InputStream	getResourceAsStream(String aKey, String[] aParams) Retrieves an InputStream for reading from the named resource.
<N> Class<N>	getResourceClass(String aName) Gets the Class of the Resource that will be returned by a call to getResource(String) or getResource(String,String[]).
URL	getResourceURL(String aKey) Retrieves the URL to the named resource.
URL	getResourceURL(String aKey, String[] aParams) Retrieves the URL to the named resource.
void	initializeExternalResources(ResourceManagerConfiguration aConfiguration, String aQualifiedContextName, Map<String,Object> aAdditionalParams) Initializes all external resources declared in a ResourceCreationSpecifier.
<N> Class<N>	loadUserClass(String name) Loads a user class using either the UIMA extension class loader (if specified) or the loader the UIMA framework is running in.
void	resolveAndValidateResourceDependencies(ExternalResourceDependency[] aDependencies, String aQualifiedContextName) Resolves a component's external resource dependencies (bindings) using this resource manager.
URL	resolveRelativePath(String aRelativePath) Attempts to resolve a relative path to an absolute path using the same mechanism that the ResourceManager uses to find resources -- a lookup in the datapath followed by a lookup in the classpath.
void	setCasManager(CasManager aCasManager) Sets the CasManager, which manages the creation and pooling of CASes.
void	setDataPath(String aPath) Sets the data path used to resolve relative paths.
void	setExtensionClassPath(ClassLoader parent, String classpath, boolean resolveResource) Sets the classpath for the UIMA extension ClassLoader and specifies if the extension ClassLoader should also be used to resolve resources.
void	setExtensionClassPath(String classpath, boolean resolveResource) Sets the classpath for the UIMA extension ClassLoader and specifies if the extension ClassLoader should also be used to resolve resources.

Method Detail

getDataPath

String getDataPath()

Gets the data path used to resolve relative paths. More than one directory may be specified by separating them with the System path.separator character (; on windows, : on UNIX).

Returns:

the data path

setDataPath

void setDataPath(String aPath)
          throws MalformedURLException

Sets the data path used to resolve relative paths. More than one directory may be specified by separating them with the System path.separator character (; on windows, : on UNIX). The elements of this path may be URLs or File paths.

Parameters:

aPath - the data path

Throws:

MalformedURLException - if an element of the path is neither a valid URL or a valid file path

resolveRelativePath

URL resolveRelativePath(String aRelativePath)
                 throws MalformedURLException

Attempts to resolve a relative path to an absolute path using the same mechanism that the ResourceManager uses to find resources -- a lookup in the datapath followed by a lookup in the classpath.

Parameters:

aRelativePath - a relative URL or file path

Returns:

the absolute URL of an actual file in the datapath or classpath, null if no file matching aRelativePath is found.

Throws:

MalformedURLException - if the path cannot be converted to a URL

getResource

Object getResource(String aName)
            throws ResourceAccessException

Gets the instance of the implementation object for a resource that has been registered under the specified name.

Parameters:

aName - the name of the resource to retrieve

Returns:

the instance of the implementation object for the resource, registered under aName, null if none exists.

Throws:

ResourceAccessException - if the requested resource could not be initialized. A common cause is that it requires parameters and the getResource(String,String[]) method should have been called instead of this method.

ResourceAccessException - tbd

getResource

Object getResource(String aName,
                   String[] aParams)
            throws ResourceAccessException

Returns one of two kinds of objects (or null): - an instance of the implementation object for a resource, that has been loaded with a DataResource resource produced by the resource given the aParms - (if there is no implementation defined for this resource) returns an instance of the DataResource, itself, produced by the resource given the aParms An example of a parameterized Resource is a dictionary whose data depend on a specified language identifier. If the implementation object class exists, but no instance has been created (yet) for the particular data resource corresponding to the parameters, then this method will create and register a new instance and call its load() api using the data resource corresponding to the parameters, and return that.

Parameters:

aName - the name of the parameterized resource to retrieve

aParams - the parameters determining which particular instance is returned and specifying a particular DataResource instance to use in initializing the implementation of the resource (if there is an implementation). If there is no implementation, the DataResource instance produced from the named Resource given these parameters is returned instead.

Returns:

one of two kinds of objects (or null): an instance of the requested implementation of the named resource where that instance has been initialized by calling its load method with the DataResource instance produced from the Resource given aParams, or, (if the named resource has no implementation) the DataResource instance corresponding to the named Resource, given aParams, or if no resource with this name exists, null.

Throws:

ResourceAccessException - if there is a resource registered under aName but it could not be instantiated for the specified parameters.

getResourceClass

<N> Class<N> getResourceClass(String aName)

Gets the Class of the Resource that will be returned by a call to getResource(String) or getResource(String,String[]). For those resource specifications which include an implementation class, this call returns that class.

Type Parameters:

N - The generic type for the returned class

Parameters:

aName - the name of a resource

Returns:

the Class for the resource named aName, null if there is no resource registered under that name.

getResourceURL

URL getResourceURL(String aKey)
            throws ResourceAccessException

Retrieves the URL to the named resource. This can be used, for example, to locate configuration or authority files.

Parameters:

aKey - the key by which the resource is identified. If this key was declared in the <externalResourceDependencies> section of the descriptor, then the resource manager is used to locate the resource. If not, the key is assumed to be the resource name and is looked up in the data path or in the class path using ClassLoader.getResource(String).

Returns:

the URL at which the named resource is located, null if the named resource could not be found.

Throws:

ResourceAccessException - if a failure occurs in accessing the resource

getResourceAsStream

InputStream getResourceAsStream(String aKey)
                         throws ResourceAccessException

Retrieves an InputStream for reading from the named resource. This can be used, for example, to read configuration or authority files.

Parameters:

aKey - the key by which the resource is identified. If this key was declared in the <externalResourceDependencies> section of the annotator's descriptor, then the resource manager is used to locate the resource. If not, the key is assumed to be the resource name and is looked up in the data path or in the class path using ClassLoader.getResource(String).

Returns:

an InputStream for reading from the named resource, null if the named resource could not be found. It is the caller's responsibility to close this stream once it is no longer needed.

Throws:

ResourceAccessException - if a failure occurs in accessing the resource

getResourceURL

URL getResourceURL(String aKey,
                   String[] aParams)
            throws ResourceAccessException

Retrieves the URL to the named resource. This can be used, for example, to locate configuration or authority files. This version of this method takes an array of parameters used to further identify the resource. This can be used, for example, with resources that vary depending on the language of the document being analyzed.

Parameters:

aKey - the key by which the resource is identified. If this key was declared in the <externalResourceDependencies> section of the annotator's descriptor, then the resource manager is used to locate the resource. If not, the key is assumed to be the resource name and is looked up in the data path or in the class path using ClassLoader.getResource(String).

aParams - parameters used to further identify the resource

Returns:

the URL at which the named resource is located, null if the named resource could not be found.

Throws:

ResourceAccessException - if a failure occurs in accessing the resource

getResourceAsStream

InputStream getResourceAsStream(String aKey,
                                String[] aParams)
                         throws ResourceAccessException

Retrieves an InputStream for reading from the named resource. This can be used, for example, to read configuration or authority files. This version of this method takes an array of parameters used to further identify the resource. This can be used, for example, with resources that vary depending on the language of the document being analyzed.

Parameters:

aKey - the key by which the resource is identified. If this key was declared in the <externalResourceDependencies> section of the annotator's descriptor, then the resource manager is used to locate the resource. If not, the key is assumed to be the resource name and is looked up in the data path or in the class path using ClassLoader.getResource(String).

aParams - parameters used to further identify the resource

Returns:

an InputStream for reading from the named resource, null if the named resource could not be found. It is the caller's responsibility to close this stream once it is no longer needed.

Throws:

ResourceAccessException - if a failure occurs in accessing the resource

initializeExternalResources

void initializeExternalResources(ResourceManagerConfiguration aConfiguration,
                                 String aQualifiedContextName,
                                 Map<String,Object> aAdditionalParams)
                          throws ResourceInitializationException

Initializes all external resources declared in a ResourceCreationSpecifier. Multi-threading: may be called on multiple threads. Initialization should be done once, on the first call External resources have a Container class representing the resource, which are instances of Resource. This may act as the implementation class, or they may also have a separately specified implementation class, which may or may not implement Resource. As part of the initialization of the Container class, by default, External Resource Bindings are processed to hook them up with defined External Resources, using the default implementation of resolveAndValidateResourceDependencies.

Parameters:

aConfiguration - the ResourceManagerConfiguration containing resource declarations and bindings

aQualifiedContextName - qualified name of UimaContext for the component (e.g. analysis engine) that is declaring these external resources

aAdditionalParams - additional parameters to be passed to resource initialize methods

Throws:

ResourceInitializationException - if an initialization failure occurs

resolveAndValidateResourceDependencies

void resolveAndValidateResourceDependencies(ExternalResourceDependency[] aDependencies,
                                            String aQualifiedContextName)
                                     throws ResourceInitializationException

Resolves a component's external resource dependencies (bindings) using this resource manager. The default implementation has special defaulting logic: If a binding specifies a non-existing resource, an attempt is made to interpret the key as a file name, looked up using the current context for relative path resolution. - If successfully found, a FileResourceSpecifier is created using the file and used as the implementing class. If no resource can be found at all, then unless the dependency is marked "optional", an ResourceInitializationException is thrown. Multi-threading: may be called on multiple threads, repeatedly for the same set of resources. Implementations should recognize this and skip repeated resolutions.

Parameters:

aDependencies - declarations of a component's dependencies on external resources

aQualifiedContextName - qualified name of UimaContext for the component (e.g. analysis engine) that is declaring these dependencies

Throws:

ResourceInitializationException - if a required dependency is not satisfied

setExtensionClassPath

void setExtensionClassPath(String classpath,
                           boolean resolveResource)
                    throws MalformedURLException

Sets the classpath for the UIMA extension ClassLoader and specifies if the extension ClassLoader should also be used to resolve resources.

Parameters:

classpath - extension ClassLoader classpath

resolveResource - if true ClassLoad resolves resources

Throws:

MalformedURLException - if a malformed URL has occurred in the classpath string.

setExtensionClassPath

void setExtensionClassPath(ClassLoader parent,
                           String classpath,
                           boolean resolveResource)
                    throws MalformedURLException

Sets the classpath for the UIMA extension ClassLoader and specifies if the extension ClassLoader should also be used to resolve resources. Also allows a parent ClassLoader to be specified.

Parameters:

parent - parent ClassLoader for the extension ClassLoader

classpath - extension ClassLoader classpath

resolveResource - if true ClassLoad resolves resources

Throws:

MalformedURLException - if a malformed URL has occurred in the classpath string.

getExtensionClassLoader

ClassLoader getExtensionClassLoader()

Returns the UIMA extension class loader.

Returns:

ClassLoader - returns the UIMA extension class loader of null if it is not available.

getCasManager

CasManager getCasManager()

Gets the CasManager, which manages the creation and pooling of CASes.

Returns:

the CasManager

setCasManager

void setCasManager(CasManager aCasManager)

Sets the CasManager, which manages the creation and pooling of CASes. This method does not normally need to be called by an application. It allows a custom CAS Manager implementation to be substituted for the default one, which may be useful when embedding UIMA in other middleware where a different CAS Manager implementation may be desired.

This method can only be called once, and must be called before creating any AnalysisEngines that use this ResourceManager. An Exception will be thrown if this method is called twice or is called after getCasManager() has already been called (which happens during AE initialization).

Parameters:

aCasManager - CAS Manager instance to plug in

getImportCache

@Deprecated
Map<String,XMLizable> getImportCache()

Deprecated. Intended just for internal use.

Gets a cache of imported descriptors, so that the parsed objects can be reused if the same URL is imported more than once.

Returns:

A map from absolute URL to the XMLizable object that was parsed from that URL

loadUserClass

<N> Class<N> loadUserClass(String name)
                    throws ClassNotFoundException

Loads a user class using either the UIMA extension class loader (if specified) or the loader the UIMA framework is running in.

Type Parameters:

N - the generic type for the returned class

Parameters:

name - the class to load

Returns:

the class

Throws:

ClassNotFoundException - -

destroy

void destroy()

Frees all resources held by this ResourceManager, and marks the ResourceManager as having been destroyed. A destroyed ResourceManager will throw an exception if an attempt is made to continue using it. Resources managed by a ResourceManager include all of the external shared Resources and a CAS Pool. The Resources managed by this manager will have their destroy() methods called, as part of the execution of this API. The framework does not call this method; it is up to the containing application to decide if and when a ResourceManager instance should be destroyed. This is because the containing application is the only knowledgeable source; for example a single ResourceManager might be used for multiple UIMA Pipelines.

getExternalResources

List<Object> getExternalResources()

Returns:

a List of External Shared Resource instances instantiated by this Resource Manager. For parameterized resources, those which have been asked for (having unique parameter sets) are included.