com.day.cq.wcm.commons
Class AbstractImageServlet

java.lang.Object
  javax.servlet.GenericServlet
      org.apache.sling.api.servlets.SlingSafeMethodsServlet
          com.day.cq.wcm.commons.AbstractImageServlet

All Implemented Interfaces:

Serializable, javax.servlet.Servlet, javax.servlet.ServletConfig

public abstract class AbstractImageServlet
extends org.apache.sling.api.servlets.SlingSafeMethodsServlet

Servers as base for image servlets

See Also:

Serialized Form

Nested Class Summary

static class

AbstractImageServlet.ImageContext Convenience class that holds usefull stuff needed for image generation

Constructor Summary

AbstractImageServlet()

Method Summary

protected boolean	checkModifiedSince(org.apache.sling.api.SlingHttpServletRequest req, org.apache.sling.api.SlingHttpServletResponse resp) Checks if the request contains a if-last-modified-since header and if the node has a jcr:lastModified property.
protected abstract com.day.image.Layer	createLayer(AbstractImageServlet.ImageContext c) Creates the image layer.
protected void	doGet(org.apache.sling.api.SlingHttpServletRequest request, org.apache.sling.api.SlingHttpServletResponse response) Handles a GET request and created the desired image.
protected double	getImageQuality() Returns the image quality.
protected String	getImageType() Returns the image type.
protected String	getImageType(String ext) Returns the image type for the given extension.
protected void	writeLayer(org.apache.sling.api.SlingHttpServletRequest request, org.apache.sling.api.SlingHttpServletResponse response, AbstractImageServlet.ImageContext context, com.day.image.Layer layer) Writes the layer to the response.

Methods inherited from class org.apache.sling.api.servlets.SlingSafeMethodsServlet

doGeneric, doHead, doOptions, doTrace, getAllowedRequestMethods, getServletInfo, handleMethodNotImplemented, mayService, service, service

Methods inherited from class javax.servlet.GenericServlet

destroy, getInitParameter, getInitParameterNames, getServletConfig, getServletContext, getServletName, init, init, log, log

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractImageServlet

public AbstractImageServlet()

Method Detail

doGet

protected void doGet(org.apache.sling.api.SlingHttpServletRequest request,
                     org.apache.sling.api.SlingHttpServletResponse response)
              throws javax.servlet.ServletException,
                     IOException

Handles a GET request and created the desired image. calls the following methods:

• checkModifiedSince(SlingHttpServletRequest, SlingHttpServletResponse)
• createLayer(ImageContext)
• writeLayer(SlingHttpServletRequest, SlingHttpServletResponse, ImageContext, Layer)

If the requested extension does not map to a known image type via getImageType(String), a 404 is responded.

Overrides:

doGet in class org.apache.sling.api.servlets.SlingSafeMethodsServlet

Throws:

javax.servlet.ServletException

IOException

writeLayer

protected void writeLayer(org.apache.sling.api.SlingHttpServletRequest request,
                          org.apache.sling.api.SlingHttpServletResponse response,
                          AbstractImageServlet.ImageContext context,
                          com.day.image.Layer layer)
                   throws IOException,
                          RepositoryException

Writes the layer to the response.

Parameters:

request - servlet request

response - servlet response

context - the context

layer - layer

Throws:

IOException - if an I/O error occurs.

RepositoryException - if an repositor error occurs.

getImageType

protected String getImageType()

Returns the image type. default "image/png"

Returns:

the image type.

getImageType

protected String getImageType(String ext)

Returns the image type for the given extension. currently there are only "png", "gif" and "jpg" supported, but an subclass can provide other mappings.

Parameters:

ext - the extension

Returns:

the image type or null.

getImageQuality

protected double getImageQuality()

Returns the image quality. default 1.0

Returns:

the image quality.

checkModifiedSince

protected boolean checkModifiedSince(org.apache.sling.api.SlingHttpServletRequest req,
                                     org.apache.sling.api.SlingHttpServletResponse resp)

Checks if the request contains a if-last-modified-since header and if the node has a jcr:lastModified property. if the properties were modified before the header a 304 is sent otherwise the response last modified header is set. If the give doesn't have the property, the parent node is searched.

Parameters:

req - the request

resp - the response

Returns:

true if the response was sent

createLayer

protected abstract com.day.image.Layer createLayer(AbstractImageServlet.ImageContext c)
                                            throws RepositoryException,
                                                   IOException

Creates the image layer.

Parameters:

c - the convenience context

Returns:

the layer

Throws:

RepositoryException - if an error occurs.

IOException - if an I/O error occurs