org.apache.dubbo.common.extension

Class ExtensionLoader<T>

java.lang.Object

org.apache.dubbo.common.extension.ExtensionLoader<T>

public class ExtensionLoader<T>
extends Object

ApplicationModel, DubboBootstrap and this class are at present designed to be singleton or static (by itself totally static or uses some static fields). So the instances returned from them are of process or classloader scope. If you want to support multiple dubbo servers in a single process, you may need to refactor these three classes.

Load dubbo extensions

• auto inject dependency extension
• auto wrap extension in wrapper
• default extension is an adaptive instance

See Also:

Service Provider in Java 5, SPI, Adaptive, Activate

Method Summary

Modifier and Type	Method and Description
void	addExtension(String name, Class<?> clazz) Register new extension via API
void	destroy()
List<T>	getActivateExtension(URL url, String key) This is equivalent to getActivateExtension(url, key, null)
List<T>	getActivateExtension(URL url, String[] values) This is equivalent to getActivateExtension(url, values, null)
List<T>	getActivateExtension(URL url, String[] values, String group) Get activate extensions.
List<T>	getActivateExtension(URL url, String key, String group) This is equivalent to getActivateExtension(url, url.getParameter(key).split(","), null)
List<T>	getActivateExtensions()
T	getAdaptiveExtension()
T	getDefaultExtension() Return default extension, return null if it's not configured.
String	getDefaultExtensionName() Return default extension name, return null if not configured.
T	getExtension(String name) Find the extension with the given name.
T	getExtension(String name, boolean wrap)
static <T> ExtensionLoader<T>	getExtensionLoader(Class<T> type) Deprecated. get extension loader from extension director of some module.
String	getExtensionName(Class<?> extensionClass)
String	getExtensionName(T extensionInstance)
T	getLoadedExtension(String name) Get extension's instance.
List<T>	getLoadedExtensionInstances()
Set<String>	getLoadedExtensions() Return the list of extensions which are already loaded.
static List<LoadingStrategy>	getLoadingStrategies() Get all Loading Strategies
T	getOrDefaultExtension(String name) Get the extension by specified name if found, or returns the default one
Set<T>	getSupportedExtensionInstances()
Set<String>	getSupportedExtensions()
boolean	hasExtension(String name)
void	replaceExtension(String name, Class<?> clazz) Deprecated. not recommended any longer, and use only when test
static void	resetExtensionLoader(Class type) Deprecated.
static void	setLoadingStrategies(LoadingStrategy... strategies)
String	toString()

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Method Detail

setLoadingStrategies

public static void setLoadingStrategies(LoadingStrategy... strategies)

getLoadingStrategies

public static List<LoadingStrategy> getLoadingStrategies()

Get all Loading Strategies

Returns:

non-null

Since:

2.7.7

See Also:

LoadingStrategy, Prioritized

getExtensionLoader

@Deprecated
public static <T> ExtensionLoader<T> getExtensionLoader(Class<T> type)

Deprecated. get extension loader from extension director of some module.

See Also:

ScopeModel.getExtensionDirector(), ScopeModel.getExtensionDirector(), ScopeModel.getExtensionDirector(), ExtensionDirector.getExtensionLoader(java.lang.Class)

resetExtensionLoader

@Deprecated
public static void resetExtensionLoader(Class type)

Deprecated.

destroy

public void destroy()

getExtensionName

public String getExtensionName(T extensionInstance)

getExtensionName

public String getExtensionName(Class<?> extensionClass)

getActivateExtension

public List<T> getActivateExtension(URL url,
                                    String key)

This is equivalent to getActivateExtension(url, key, null)

Parameters:

url - url

key - url parameter key which used to get extension point names

Returns:

extension list which are activated.

See Also:

getActivateExtension(org.apache.dubbo.common.URL, String, String)

getActivateExtension

public List<T> getActivateExtension(URL url,
                                    String[] values)

This is equivalent to getActivateExtension(url, values, null)

Parameters:

url - url

values - extension point names

Returns:

extension list which are activated

See Also:

getActivateExtension(org.apache.dubbo.common.URL, String[], String)

getActivateExtension

public List<T> getActivateExtension(URL url,
                                    String key,
                                    String group)

This is equivalent to getActivateExtension(url, url.getParameter(key).split(","), null)

Parameters:

url - url

key - url parameter key which used to get extension point names

group - group

Returns:

extension list which are activated.

See Also:

getActivateExtension(org.apache.dubbo.common.URL, String[], String)

getActivateExtension

public List<T> getActivateExtension(URL url,
                                    String[] values,
                                    String group)

Get activate extensions.

Parameters:

url - url

values - extension point names

group - group

Returns:

extension list which are activated

See Also:

Activate

getActivateExtensions

public List<T> getActivateExtensions()

getLoadedExtension

public T getLoadedExtension(String name)

Get extension's instance. Return null if extension is not found or is not initialized. Pls. note that this method will not trigger extension load.

In order to trigger extension load, call getExtension(String) instead.

See Also:

getExtension(String)

getLoadedExtensions

public Set<String> getLoadedExtensions()

Return the list of extensions which are already loaded.

Usually getSupportedExtensions() should be called in order to get all extensions.

See Also:

getSupportedExtensions()

getLoadedExtensionInstances

public List<T> getLoadedExtensionInstances()

getExtension

public T getExtension(String name)

Find the extension with the given name.

Throws:

IllegalStateException - If the specified extension is not found.

getExtension

public T getExtension(String name,
                      boolean wrap)

getOrDefaultExtension

public T getOrDefaultExtension(String name)

Get the extension by specified name if found, or returns the default one

Parameters:

name - the name of extension

Returns:

non-null

getDefaultExtension

public T getDefaultExtension()

Return default extension, return null if it's not configured.

hasExtension

public boolean hasExtension(String name)

getSupportedExtensions

public Set<String> getSupportedExtensions()

getSupportedExtensionInstances

public Set<T> getSupportedExtensionInstances()

getDefaultExtensionName

public String getDefaultExtensionName()

Return default extension name, return null if not configured.

addExtension

public void addExtension(String name,
                         Class<?> clazz)

Register new extension via API

Parameters:

name - extension name

clazz - extension class

Throws:

IllegalStateException - when extension with the same name has already been registered.

replaceExtension

@Deprecated
public void replaceExtension(String name,
                                         Class<?> clazz)

Deprecated. not recommended any longer, and use only when test

Replace the existing extension via API

Parameters:

name - extension name

clazz - extension class

Throws:

IllegalStateException - when extension to be placed doesn't exist

getAdaptiveExtension

public T getAdaptiveExtension()

toString

public String toString()

Overrides:

toString in class Object