Package org.apache.tika.config

Class ServiceLoader

java.lang.Object

org.apache.tika.config.ServiceLoader

public class ServiceLoader
extends Object

Internal utility class that Tika uses to look up service providers.

Since:

Apache Tika 0.9

Constructor Summary

Constructors

Constructor	Description
ServiceLoader()
ServiceLoader(ClassLoader loader)
ServiceLoader(ClassLoader loader, LoadErrorHandler handler)
ServiceLoader(ClassLoader loader, LoadErrorHandler handler, boolean dynamic)
ServiceLoader(ClassLoader loader, LoadErrorHandler handler, InitializableProblemHandler initializableProblemHandler, boolean dynamic)

Method Summary

Modifier and Type	Method	Description
Enumeration<URL>	findServiceResources(String filePattern)	Returns all the available service resources matching the given pattern, such as all instances of tika-mimetypes.xml on the classpath, or all org.apache.tika.parser.Parser service files.
InitializableProblemHandler	getInitializableProblemHandler()	Returns the handler for problems with initializables
ClassLoader	getLoader()
LoadErrorHandler	getLoadErrorHandler()	Returns the load error handler used by this loader.
InputStream	getResourceAsStream(String name)	Returns an input stream for reading the specified resource from the configured class loader.
<T> Class<? extends T>	getServiceClass(Class<T> iface, String name)	Loads and returns the named service class that's expected to implement the given interface.
protected <T> List<String>	identifyStaticServiceProviders(Class<T> iface)	Returns the defined static service providers of the given type, without attempting to load them.
boolean	isDynamic()	Returns if the service loader is static or dynamic
<T> List<T>	loadDynamicServiceProviders(Class<T> iface)	Returns the available dynamic service providers of the given type.
<T> List<T>	loadServiceProviders(Class<T> iface)	Returns all the available service providers of the given type.
<T> List<T>	loadStaticServiceProviders(Class<T> iface)
<T> List<T>	loadStaticServiceProviders(Class<T> iface, Collection<Class<? extends T>> excludes)	Returns the available static service providers of the given type.
static void	setContextClassLoader(ClassLoader loader)	Sets the context class loader to use for all threads that access this class.

Methods inherited from class java.lang.Object

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

Constructor Detail

ServiceLoader

public ServiceLoader(ClassLoader loader,
                     LoadErrorHandler handler,
                     InitializableProblemHandler initializableProblemHandler,
                     boolean dynamic)

ServiceLoader

public ServiceLoader(ClassLoader loader,
                     LoadErrorHandler handler,
                     boolean dynamic)

ServiceLoader

public ServiceLoader(ClassLoader loader,
                     LoadErrorHandler handler)

ServiceLoader

public ServiceLoader(ClassLoader loader)

ServiceLoader

public ServiceLoader()

Method Detail

setContextClassLoader

public static void setContextClassLoader(ClassLoader loader)

Sets the context class loader to use for all threads that access this class. Used for example in an OSGi environment to avoid problems with the default context class loader.

Parameters:

loader - default context class loader, or null to automatically pick the loader

isDynamic

public boolean isDynamic()

Returns if the service loader is static or dynamic

Returns:

dynamic or static loading

Since:

Apache Tika 1.10

getLoadErrorHandler

public LoadErrorHandler getLoadErrorHandler()

Returns the load error handler used by this loader.

Returns:

load error handler

Since:

Apache Tika 1.3

getInitializableProblemHandler

public InitializableProblemHandler getInitializableProblemHandler()

Returns the handler for problems with initializables

Returns:

handler for problems with initializables

Since:

Apache Tika 1.15.1

getResourceAsStream

public InputStream getResourceAsStream(String name)

Returns an input stream for reading the specified resource from the configured class loader.

Parameters:

name - resource name

Returns:

input stream, or null if the resource was not found

Since:

Apache Tika 1.1

See Also:

ClassLoader.getResourceAsStream(String)

getLoader

public ClassLoader getLoader()

Returns:

ClassLoader used by this ServiceLoader

Since:

Apache Tika 1.15.1

See Also:

for the context's ClassLoader

getServiceClass

public <T> Class<? extends T> getServiceClass(Class<T> iface,
                                              String name)
                                       throws ClassNotFoundException

Loads and returns the named service class that's expected to implement the given interface.

Note that this class does not use the LoadErrorHandler, a ClassNotFoundException is always returned for unknown classes or classes of the wrong type

Parameters:

iface - service interface

name - service class name

Returns:

service class

Throws:

ClassNotFoundException - if the service class can not be found or does not implement the given interface

Since:

Apache Tika 1.1

See Also:

Class.forName(String, boolean, ClassLoader)

findServiceResources

public Enumeration<URL> findServiceResources(String filePattern)

Returns all the available service resources matching the given pattern, such as all instances of tika-mimetypes.xml on the classpath, or all org.apache.tika.parser.Parser service files.

loadServiceProviders

public <T> List<T> loadServiceProviders(Class<T> iface)

Returns all the available service providers of the given type. As of versions after 2.4.1, this removes duplicate classes

Parameters:

iface - service provider interface

Returns:

available service providers

loadDynamicServiceProviders

public <T> List<T> loadDynamicServiceProviders(Class<T> iface)

Returns the available dynamic service providers of the given type. The returned list is newly allocated and may be freely modified by the caller.

Parameters:

iface - service provider interface

Returns:

dynamic service providers

Since:

Apache Tika 1.2

identifyStaticServiceProviders

protected <T> List<String> identifyStaticServiceProviders(Class<T> iface)

Returns the defined static service providers of the given type, without attempting to load them. The providers are loaded using the service provider mechanism using the configured class loader (if any).

Parameters:

iface - service provider interface

Returns:

static list of uninitialised service providers

Since:

Apache Tika 1.6

loadStaticServiceProviders

public <T> List<T> loadStaticServiceProviders(Class<T> iface)

loadStaticServiceProviders

public <T> List<T> loadStaticServiceProviders(Class<T> iface,
                                              Collection<Class<? extends T>> excludes)

Returns the available static service providers of the given type. The providers are loaded using the service provider mechanism using the configured class loader (if any). The returned list is newly allocated and may be freely modified by the caller.

Parameters:

iface - service provider interface

excludes - -- do not load these classes

Returns:

static service providers

Since:

Apache Tika 1.2