Package com.unboundid.directory.sdk.http.api

Class HTTPServletExtension

java.lang.Object

com.unboundid.directory.sdk.http.api.HTTPServletExtension

All Implemented Interfaces:

Configurable, ExampleUsageProvider, Reconfigurable<HTTPServletExtensionConfig>, UnboundIDExtension

@Extensible
@DirectoryServerExtension
@DirectoryProxyServerExtension(appliesToLocalContent=true,
                               appliesToRemoteContent=true)
@MetricsEngineExtension
@BrokerExtension
@SynchronizationServerExtension(appliesToLocalContent=true,
                                appliesToSynchronizedContent=true)
@ThreadSafety(level=INTERFACE_THREADSAFE)
public abstract class HTTPServletExtension
extends java.lang.Object
implements UnboundIDExtension, Reconfigurable<HTTPServletExtensionConfig>, ExampleUsageProvider

This class defines an API that must be implemented by extensions which create servlets for use with an HTTP connection handler.

Configuring HTTP Servlet Extensions

In order to configure an HTTP servlet extension created using this API, use a command like:

      dsconfig create-http-servlet-extension \
           --extension-name "{extension-name}" \
           --type third-party \
           --set "extension-class:{class-name}" \
           --set "extension-argument:{name=value}"
 

where "{extension-name}" is the name to use for the HTTP servlet extension instance, "{class-name}" is the fully-qualified name of the Java class that extends com.unboundid.directory.sdk.ds.api.HTTPServletExtension, and "{name=value}" represents name-value pairs for any arguments to provide to the HTTP servlet extension. If multiple arguments should be provided to the HTTP servlet extension, then the "--set extension-argument:{name=value}" option should be provided multiple times.

Note that the server also provides the ability to run full web applications, by creating a Web Application Extension and specifying the necessary properties. If that web application needs to perform internal operations or interact with the server in any way, then the WebAppServerContextFactory class may be called from the web application in order to obtain a server context.

See Also:

ScriptedHTTPServletExtension

Constructor Summary

Constructors

Constructor	Description
HTTPServletExtension()	Creates a new instance of this HTTP servlet extension.

Method Summary

Modifier and Type	Method	Description
ResultCode	applyConfiguration(HTTPServletExtensionConfig config, ArgumentParser parser, java.util.List<java.lang.String> adminActionsRequired, java.util.List<java.lang.String> messages)	Attempts to apply the configuration from the provided argument parser to this extension.
abstract javax.servlet.http.HttpServlet	createServlet(HTTPServerContext serverContext, HTTPServletExtensionConfig config, ArgumentParser parser)	Creates an HTTP servlet extension using the provided information.
void	defineConfigArguments(ArgumentParser parser)	Updates the provided argument parser to define any configuration arguments which may be used by this extension.
void	doPostRegistrationProcessing()	Performs any processing that may be needed after the servlet has been registered with the servlet engine.
void	doPostShutdownProcessing()	Performs any processing that may be needed after the servlet has been taken out of service and the associated servlet engine has been shut down.
java.util.Map<java.util.List<java.lang.String>,java.lang.String>	getExamplesArgumentSets()	Retrieves a map containing examples of configurations that may be used for this extension.
abstract java.lang.String[]	getExtensionDescription()	Retrieves a human-readable description for this extension.
abstract java.lang.String	getExtensionName()	Retrieves a human-readable name for this extension.
java.util.List<javax.servlet.Filter>	getServletFilters()	Retrieves a list of servlet filter instances that should be installed with the created servlet instance, in the order they should be invoked.
int	getServletInitOrder()	Retrieves the order in which the servlet should be started.
java.util.Map<java.lang.String,java.lang.String>	getServletInitParameters()	Retrieves a map of initialization parameters that should be provided to the servlet when it is initialized.
abstract java.util.List<java.lang.String>	getServletPaths()	Retrieves a list of the request paths for which the associated servlet should be invoked.
boolean	isConfigurationAcceptable(HTTPServletExtensionConfig config, ArgumentParser parser, java.util.List<java.lang.String> unacceptableReasons)	Indicates whether the configuration represented by the provided argument parser is acceptable for use by this extension.

Methods inherited from class java.lang.Object

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

Constructor Detail

HTTPServletExtension

public HTTPServletExtension()

Creates a new instance of this HTTP servlet extension. All HTTP servlet extension implementations must include a default constructor, but any initialization should generally be done in the createServlet method.

Method Detail

getExtensionName

public abstract java.lang.String getExtensionName()

Retrieves a human-readable name for this extension.

Specified by:

getExtensionName in interface UnboundIDExtension

Returns:

A human-readable name for this extension.

getExtensionDescription

public abstract java.lang.String[] getExtensionDescription()

Retrieves a human-readable description for this extension. Each element of the array that is returned will be considered a separate paragraph in generated documentation.

Specified by:

getExtensionDescription in interface UnboundIDExtension

Returns:

A human-readable description for this extension, or null or an empty array if no description should be available.

defineConfigArguments

public void defineConfigArguments(ArgumentParser parser)
                           throws ArgumentException

Updates the provided argument parser to define any configuration arguments which may be used by this extension. The argument parser may also be updated to define relationships between arguments (e.g., to specify required, exclusive, or dependent argument sets).

Specified by:

defineConfigArguments in interface Configurable

Parameters:

parser - The argument parser to be updated with the configuration arguments which may be used by this extension.

Throws:

ArgumentException - If a problem is encountered while updating the provided argument parser.

isConfigurationAcceptable

public boolean isConfigurationAcceptable(HTTPServletExtensionConfig config,
                                         ArgumentParser parser,
                                         java.util.List<java.lang.String> unacceptableReasons)

Indicates whether the configuration represented by the provided argument parser is acceptable for use by this extension. The parser will have been used to parse any configuration available for this extension, and any automatic validation will have been performed. This method may be used to perform any more complex validation which cannot be performed automatically by the argument parser.

Specified by:

isConfigurationAcceptable in interface Reconfigurable<HTTPServletExtensionConfig>

Parameters:

config - The general configuration for this extension.

parser - The argument parser that has been used to parse the proposed configuration for this extension.

unacceptableReasons - A list to which messages may be added to provide additional information about why the provided configuration is not acceptable.

Returns:

true if the configuration in the provided argument parser appears to be acceptable, or false if not.

applyConfiguration

public ResultCode applyConfiguration(HTTPServletExtensionConfig config,
                                     ArgumentParser parser,
                                     java.util.List<java.lang.String> adminActionsRequired,
                                     java.util.List<java.lang.String> messages)

Attempts to apply the configuration from the provided argument parser to this extension.

Specified by:

applyConfiguration in interface Reconfigurable<HTTPServletExtensionConfig>

Parameters:

config - The general configuration for this extension.

parser - The argument parser that has been used to parse the new configuration for this extension.

adminActionsRequired - A list to which messages may be added to provide additional information about any additional administrative actions that may be required to apply some of the configuration changes.

messages - A list to which messages may be added to provide additional information about the processing performed by this method.

Returns:

A result code providing information about the result of applying the configuration change. A result of SUCCESS should be used to indicate that all processing completed successfully. Any other result will indicate that a problem occurred during processing.

getExamplesArgumentSets

public java.util.Map<java.util.List<java.lang.String>,java.lang.String> getExamplesArgumentSets()

Retrieves a map containing examples of configurations that may be used for this extension. The map key should be a list of sample arguments, and the corresponding value should be a description of the behavior that will be exhibited by the extension when used with that configuration.

Specified by:

getExamplesArgumentSets in interface ExampleUsageProvider

Returns:

A map containing examples of configurations that may be used for this extension. It may be null or empty if there should not be any example argument sets.

createServlet

public abstract javax.servlet.http.HttpServlet createServlet(HTTPServerContext serverContext,
                                                             HTTPServletExtensionConfig config,
                                                             ArgumentParser parser)
                                                      throws LDAPException

Creates an HTTP servlet extension using the provided information.

Parameters:

serverContext - A handle to the server context for the server in which this extension is running.

config - The general configuration for this HTTP servlet extension.

parser - The argument parser which has been initialized from the configuration for this HTTP servlet extension.

Returns:

The HTTP servlet that has been created.

Throws:

LDAPException - If a problem is encountered while attempting to create the HTTP servlet.

getServletPaths

public abstract java.util.List<java.lang.String> getServletPaths()

Retrieves a list of the request paths for which the associated servlet should be invoked. This method will be called after the createServlet(com.unboundid.directory.sdk.http.types.HTTPServerContext, com.unboundid.directory.sdk.http.config.HTTPServletExtensionConfig, com.unboundid.util.args.ArgumentParser) method has been used to create the servlet instance.

Returns:

A list of the request paths for which the associated servlet should be invoked.

getServletInitParameters

public java.util.Map<java.lang.String,java.lang.String> getServletInitParameters()

Retrieves a map of initialization parameters that should be provided to the servlet when it is initialized.

Returns:

A map of initialization parameters that should be provided to the servlet when it is initialized, or an empty map if no initialization parameters are needed.

getServletInitOrder

public int getServletInitOrder()

Retrieves the order in which the servlet should be started. A value greater than or equal to zero guarantees that the servlet will be started as soon as the servlet engine has been started, in order of ascending servlet init order values, before the doPostRegistrationProcessing method has been called. If the value is less than zero, the servlet may not be started until a request is received for one of its registered paths.

Returns:

The order in which the servlet should be started, or a negative value if startup order does not matter.

getServletFilters

public java.util.List<javax.servlet.Filter> getServletFilters()

Retrieves a list of servlet filter instances that should be installed with the created servlet instance, in the order they should be invoked. If the servlet is to be registered with multiple paths, then these filters will be installed for all of those paths.

Returns:

A list of servlet filter instances that should be installed with the created servlet instance, in the order that they should be invoked. It may be null or empty if no servlet filters should be installed.

doPostRegistrationProcessing

public void doPostRegistrationProcessing()

Performs any processing that may be needed after the servlet has been registered with the servlet engine. If the value returned from getServletInitOrder() is greater than or equal to zero, then the servlet will have been started before this method is called. If the value returned from getServletInitOrder() is negative, then the servlet may or may not have been started by the time this method is called.

Note that the associated servlet can also perform any necessary initialization processing in the init method provided by the servlet API.

doPostShutdownProcessing

public void doPostShutdownProcessing()

Performs any processing that may be needed after the servlet has been taken out of service and the associated servlet engine has been shut down.

Note that the associated servlet can also perform any necessary finalization processing in the destroy method provided by the servlet API. That method will be called after the servlet has been taken out of service, but before the servlet engine has been shut down.