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publicfinalclassServiceFactoryFactory
This class is not intended for end users.
Provide factory instances for AppEngine APIs. Each API will have an associated
FactoryProvider registered with this class. N.B. Once <xref uid="com.google.appengine.spi.ServiceFactoryFactory.
To construct the runtime mapping, this class first uses java.util.ServiceLoader to
find all registered FactoryProvider entities using the ClassLoader of
ServiceFactoryFactory. Finally, the explicitly registered providers
<xref uid="com.google.appengine.spi.ServiceFactoryFactory.register(com.google.appengine.spi.FactoryProvider<I>)" data-throw-if-not-resolved="false">#register(FactoryProvider) are merged in.
If ServiceLoader locates multiple providers for a given factory interface, the
ambiguity can be resolved by using the ServiceProvider#precedence annotation property
(higher precedence wins; the google implementations all have precedence
Integer.MIN_VALUE). An exception is raised if the ambiguity cannot be resolved. Note that
explicit registration (<xref uid="com.google.appengine.spi.ServiceFactoryFactory.register(com.google.appengine.spi.FactoryProvider<I>)" data-throw-if-not-resolved="false">#register(FactoryProvider)) always takes precedence (it does not
honor the ServiceProvider#precedence annotation property).
If this system property is set to "true" the thread context classloader is used (if non-null)
when looking up API service implementations. Otherwise the class loader of this class is used.
Explicitly register a provider. This does not take the precedence (see
FactoryProvider#getPrecedence()) of the provider into consideration; subsequent
registrations will always override previous ones.
Used by AppEngine service factories. Returns an instance of the factory implementing the
interface provide by base. Since there must always be a provider registered for a given
base, an error will be raised if no appropriate registration is found.
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Hard to understand","hardToUnderstand","thumb-down"],["Incorrect information or sample code","incorrectInformationOrSampleCode","thumb-down"],["Missing the information/samples I need","missingTheInformationSamplesINeed","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-09-04 UTC."],[[["\u003cp\u003e\u003ccode\u003eServiceFactoryFactory\u003c/code\u003e is designed for internal use and provides factory instances for AppEngine APIs.\u003c/p\u003e\n"],["\u003cp\u003eIt uses \u003ccode\u003ejava.util.ServiceLoader\u003c/code\u003e to discover and register \u003ccode\u003eFactoryProvider\u003c/code\u003e entities, mapping APIs to factories.\u003c/p\u003e\n"],["\u003cp\u003eMultiple providers for the same factory interface are resolved using the \u003ccode\u003eServiceProvider#precedence\u003c/code\u003e property, with higher precedence winning, except for explicit registrations which take absolute precedence.\u003c/p\u003e\n"],["\u003cp\u003eThe \u003ccode\u003eregister(FactoryProvider)\u003c/code\u003e method allows for the explicit registration of providers, overriding any previously registered ones.\u003c/p\u003e\n"],["\u003cp\u003eThe \u003ccode\u003egetFactory(Class<T> base)\u003c/code\u003e method is used by AppEngine to retrieve an instance of a factory that implements a given interface, raising an error if no appropriate provider is found.\u003c/p\u003e\n"]]],[],null,["# Class ServiceFactoryFactory (2.0.0)\n\n public final class ServiceFactoryFactory\n\n**This class is not intended for end users.**\n\nProvide factory instances for AppEngine APIs. Each API will have an associated\n[FactoryProvider](/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.spi.FactoryProvider) registered with this class. N.B. *Once \\\u003cxref uid=\"com.google.appengine.spi.ServiceFactoryFactory.*\n\nTo construct the runtime mapping, this class first uses `java.util.ServiceLoader` to\nfind all registered [FactoryProvider](/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.spi.FactoryProvider) entities using the `ClassLoader` of\n`ServiceFactoryFactory`. Finally, the explicitly registered providers\n\\\u003cxref uid=\"com.google.appengine.spi.ServiceFactoryFactory.*register(com.google.appengine.spi.FactoryProvider\\\u003cI\\\u003e)\" data-throw-if-not-resolved=\"false\"\\\u003e#register(FactoryProvider) are merged in.*\n\n*If `ServiceLoader` locates multiple providers for a given factory interface, the\nambiguity can be resolved by using the [ServiceProvider#precedence](/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.spi.ServiceProvider#com_google_appengine_spi_ServiceProvider_precedence_) annotation property\n(higher precedence wins; *the google implementations all have precedence\nInteger.MIN_VALUE* ). An exception is raised if the ambiguity cannot be resolved. Note that\nexplicit registration (\\\u003cxref uid=\"com.google.appengine.spi.ServiceFactoryFactory.*register(com.google.appengine.spi.FactoryProvider\\\u003cI\\\u003e)\" data-throw-if-not-resolved=\"false\"\\\u003e#register(FactoryProvider)) always takes precedence (it does not\nhonor the [ServiceProvider#precedence](/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.spi.ServiceProvider#com_google_appengine_spi_ServiceProvider_precedence_) annotation property).**\n\nInheritance\n-----------\n\n[java.lang.Object](https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html) \\\u003e ServiceFactoryFactory \n\nInherited Members\n-----------------\n\n[Object.clone()](https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#clone--) \n[Object.equals(Object)](https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#equals-java.lang.Object-) \n[Object.finalize()](https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#finalize--) \n[Object.getClass()](https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#getClass--) \n[Object.hashCode()](https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#hashCode--) \n[Object.notify()](https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#notify--) \n[Object.notifyAll()](https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#notifyAll--) \n[Object.toString()](https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#toString--) \n[Object.wait()](https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#wait--) \n[Object.wait(long)](https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#wait-long-) \n[Object.wait(long,int)](https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#wait-long-int-)\n\nStatic Fields\n-------------\n\n### USE_THREAD_CONTEXT_CLASSLOADER_PROPERTY\n\n public static final String USE_THREAD_CONTEXT_CLASSLOADER_PROPERTY\n\nIf this system property is set to \"true\" the thread context classloader is used (if non-null)\nwhen looking up API service implementations. Otherwise the class loader of this class is used.\n\nStatic Methods\n--------------\n\n### \\\u003cI\\\u003eregister(FactoryProvider\\\u003cI\\\u003e p)\n\n public static synchronized void \u003cI\u003eregister(FactoryProvider\u003cI\u003e p)\n\nExplicitly register a provider. This does not take the precedence (see\nFactoryProvider#getPrecedence()) of the provider into consideration; subsequent\nregistrations will always override previous ones.\n\n### \\\u003cT\\\u003egetFactory(Class\\\u003cT\\\u003e base)\n\n public static T \u003cT\u003egetFactory(Class\u003cT\u003e base)\n\nUsed by AppEngine service factories. Returns an instance of the factory implementing the\ninterface provide by `base`. Since there must always be a provider registered for a given\nbase, an error will be raised if no appropriate registration is found.\n\nConstructors\n------------\n\n### ServiceFactoryFactory()\n\n public ServiceFactoryFactory()"]]
