nextapp.echo.webcontainer.service
Class ImageService

java.lang.Object
  nextapp.echo.webcontainer.service.ImageService

All Implemented Interfaces:

Service

public class ImageService
extends java.lang.Object
implements Service

A Service which renders stream image references (including ResourceImageReferences and AwtImageReferences.

Field Summary

static ImageService

INSTANCE Singleton instance of this Service.

Fields inherited from interface nextapp.echo.webcontainer.Service

DO_NOT_CACHE

Constructor Summary

ImageService()

Method Summary

java.lang.String	createUri(UserInstance userInstance, java.lang.String imageId) Creates a URI to retrieve a specific image for a specific component from the server.
java.lang.String	getId() Returns the unique identifier of this service.
nextapp.echo.app.ImageReference	getImage(UserInstance userInstance, java.lang.String imageId) Gets the image with the specified id.
int	getVersion() Returns the version of the service to be retrieved.
void	renderImage(Connection conn, nextapp.echo.app.ImageReference imageReference) Renders the specified image to the given connection.
void	service(Connection conn) Services an HTTP request.

Methods inherited from class java.lang.Object

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

Field Detail

INSTANCE

public static final ImageService INSTANCE

Singleton instance of this Service.

Constructor Detail

ImageService

public ImageService()

Method Detail

getId

public java.lang.String getId()

Description copied from interface: Service

Returns the unique identifier of this service.

Specified by:

getId in interface Service

Returns:

the unique identifier of this service

See Also:

Service.getId()

getVersion

public int getVersion()

Description copied from interface: Service

Returns the version of the service to be retrieved. When a service is requested with an updated version number, a non-cached copy will be used. getVersion() should return distinct values whenever the service's content may have changed.

Specified by:

getVersion in interface Service

Returns:

the current version number of the service

See Also:

Service.getVersion()

createUri

public java.lang.String createUri(UserInstance userInstance,
                                  java.lang.String imageId)

Creates a URI to retrieve a specific image for a specific component from the server.

Parameters:

userInstance - the relevant application user instance

imageId - the unique id to retrieve the image from the ContainerInstance

renderImage

public void renderImage(Connection conn,
                        nextapp.echo.app.ImageReference imageReference)
                 throws java.io.IOException

Renders the specified image to the given connection. Implementations should set the response content type, and write image data to the response OutputStream.

Parameters:

conn - the Connection on which to render the image

imageReference - the image to be rendered

Throws:

java.io.IOException - if the image cannot be rendered

getImage

public nextapp.echo.app.ImageReference getImage(UserInstance userInstance,
                                                java.lang.String imageId)

Gets the image with the specified id.

Parameters:

userInstance - the UserInstance from which the image was requested

imageId - the id of the image

Returns:

the image if found, null otherwise.

service

public void service(Connection conn)
             throws java.io.IOException

Description copied from interface: Service

Services an HTTP request. Information about the HTTP request as well as methods for issuing a response are available from the provided Connection object.

Specified by:

service in interface Service

Parameters:

conn - a Connection object which wraps HttpServletRequest and HttpServletResponse objects and provides access to the facilities of the Echo application container

Throws:

java.io.IOException - in the event of errors related to processing the HTTP request or producing a response

See Also:

Service.service(nextapp.echo.webcontainer.Connection)