org.hippoecm.hst.servlet

Class BinariesServlet

java.lang.Object

javax.servlet.GenericServlet

javax.servlet.http.HttpServlet

org.hippoecm.hst.servlet.BinariesServlet

All Implemented Interfaces:

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

public class BinariesServlet
extends javax.servlet.http.HttpServlet

Serves binary files from the repository. Binary files are represented by nodes.

This servlet has the ability to set the "Content-Disposition" header in the HTTP response to tell browsers to download a binary file instead of trying to display the file directly. This needs some configuration, which is described below.

Content disposition configuration

To configure which mime types to enable content dispositioning for, set the "contentDispositionContentTypes" init param in the web.xml in which this servlet is defined. Example:

 <init-param>
     <param-name>contentDispositionContentTypes</param-name>
     <param-value>
         application/pdf,
         application/rtf,
         application/excel
     </param-value>
 </init-param>
 

In the above init param configuration, you can also set glob style configurations such as '*/*' or 'application/*'. Also, you can configure the JCR property to get the file name from. The file name is used to send along in the HTTP response for content dispositioning. To configure this, set the "contentDispositionFilenameProperty" init param in the web.xml in which this servlet is defined. Example:

 <init-param>
     <param-name>contentDispositionFilenameProperty</param-name>
     <param-value>demosite:filename</param-value>
 </init-param>
 

The contentDispositionFilenameProperty is being encoded. By default, we try to do this user-agent-agnostic. This is preferrable when using caching reverse proxies in front of your application. In user-agent-agnostic mode, we try to convert filenames consisting non ascii chars to their base form, in other words, replace diacritics. However for for example a language like Chinese this won't work. Then, you might want to opt for the user-agent-specific mode. You then have to take care of your reverse proxies taking care of the user-agent. They thus should take the user-agent into account. Also see ContentDispositionUtils.encodeFileName(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse, java.lang.String, java.lang.String). Changing the default user-agent-agnostic mode to user-agent-specific mode can be done by adding the init-param:

 <init-param>
     <param-name>contentDispositionFilenameEncoding</param-name>
     <param-value>user-agent-specific</param-value>
 </init-param>
 

You can also configure multiple JCR property names in the above init parameter by comma-separated value.

Sometimes you do not want to set the content disposition headers for all files of a certain mime-type. You can do this by adding a request parameter to the url to the resource. In the template you should add the request param to the link.

 <hst:link var="link" hippobean="${item}">
     <hst:param name="forceDownload" value="true"/>
 </hst:link>
 

If you want to have a different name for the parameter you can explicitly set the name as an init parameter of the BinariesServlet.

 <init-param>
     <param-name>forceContentDispositionRequestParamName</param-name>
     <param-value>forceDownload</param-value>
 </init-param>
 

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected class	BinariesServlet.DefaultBinaryPageFactory

Field Summary

Fields

Modifier and Type	Field and Description
static String	BASE_BINARIES_CONTENT_PATH_INIT_PARAM
static String	BINARY_DATA_PROP_NAME_INIT_PARAM
static String	BINARY_LAST_MODIFIED_PROP_NAME_INIT_PARAM
static String	BINARY_MIME_TYPE_PROP_NAME_INIT_PARAM
static String	BINARY_RESOURCE_NODE_TYPE_INIT_PARAM
static String	CONTENT_DISPOSITION_CONTENT_TYPES_INIT_PARAM
static String	CONTENT_DISPOSITION_FILENAME_ENCODING_INIT_PARAM The init param indicating whether the fileName for the content disposition can be encoded 'user-agent-specific' or 'user-agent-agnostic', also see ContentDispositionUtils.encodeFileName(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse, java.lang.String, java.lang.String)
static String	CONTENT_DISPOSITION_FILENAME_PROPERTY_INIT_PARAM
static String	DEFAULT_FORCE_CONTENT_DISPOSITION_PARAM_NAME
static String	FORCE_CONTENT_DISPOSITION_INIT_PARAM
static String	SET_CONTENT_LENGTH_HEADER_INIT_PARAM

Constructor Summary

Constructors

Constructor and Description
BinariesServlet()

Method Summary

Modifier and Type	Method and Description
protected BinaryPageFactory	createBinaryPageFactory()
void	doGet(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response)
protected void	doInit()
protected BinaryPage	getBinaryPage(javax.servlet.http.HttpServletRequest request, String resourcePath)
protected boolean	getBooleanInitParameter(String paramName, boolean defaultValue)
protected String	getInitParameter(String paramName, String defaultValue)
protected long	getLastModifiedFromResource(javax.servlet.http.HttpServletRequest request, String resourcePath)
protected long	getLongInitParameter(String paramName, long defaultValue)
protected BinaryPage	getPageFromCacheOrLoadPage(javax.servlet.http.HttpServletRequest request)
protected InputStream	getRepositoryResourceStream(javax.jcr.Session session, BinaryPage page)
protected javax.jcr.Node	getResourceNode(javax.jcr.Session session, String resourcePath) Retrieve the JCR node representing a resource
protected String	getSessionUserID(javax.servlet.http.HttpServletRequest request)
protected BinaryPage	getValidatedPageFromCache(javax.servlet.http.HttpServletRequest request, BinaryPage page)
void	init(javax.servlet.ServletConfig config)
protected void	initBinaryPageValues(javax.jcr.Session session, BinaryPage page)
protected boolean	isPageStale(javax.servlet.http.HttpServletRequest request, BinaryPage page) Hook for subclasses to check whether a previously cached page should be recreated.
protected void	storeResourceOnBinaryPage(BinaryPage page, javax.jcr.Node resourceNode) Stores the binary content of resourceNode on the page unless the page is marked to be uncacheable.
protected void	writeResponse(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, BinaryPage page)

Methods inherited from class javax.servlet.http.HttpServlet

doDelete, doHead, doOptions, doPost, doPut, doTrace, getLastModified, service, service

Methods inherited from class javax.servlet.GenericServlet

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

Methods inherited from class java.lang.Object

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

Field Detail

SET_CONTENT_LENGTH_HEADER_INIT_PARAM

public static final String SET_CONTENT_LENGTH_HEADER_INIT_PARAM

See Also:

Constant Field Values

BASE_BINARIES_CONTENT_PATH_INIT_PARAM

public static final String BASE_BINARIES_CONTENT_PATH_INIT_PARAM

See Also:

Constant Field Values

CONTENT_DISPOSITION_CONTENT_TYPES_INIT_PARAM

public static final String CONTENT_DISPOSITION_CONTENT_TYPES_INIT_PARAM

See Also:

Constant Field Values

CONTENT_DISPOSITION_FILENAME_PROPERTY_INIT_PARAM

public static final String CONTENT_DISPOSITION_FILENAME_PROPERTY_INIT_PARAM

See Also:

Constant Field Values

CONTENT_DISPOSITION_FILENAME_ENCODING_INIT_PARAM

public static final String CONTENT_DISPOSITION_FILENAME_ENCODING_INIT_PARAM

The init param indicating whether the fileName for the content disposition can be encoded 'user-agent-specific' or 'user-agent-agnostic', also see ContentDispositionUtils.encodeFileName(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse, java.lang.String, java.lang.String)

See Also:

Constant Field Values

FORCE_CONTENT_DISPOSITION_INIT_PARAM

public static final String FORCE_CONTENT_DISPOSITION_INIT_PARAM

See Also:

Constant Field Values

DEFAULT_FORCE_CONTENT_DISPOSITION_PARAM_NAME

public static final String DEFAULT_FORCE_CONTENT_DISPOSITION_PARAM_NAME

See Also:

Constant Field Values

BINARY_RESOURCE_NODE_TYPE_INIT_PARAM

public static final String BINARY_RESOURCE_NODE_TYPE_INIT_PARAM

See Also:

Constant Field Values

BINARY_DATA_PROP_NAME_INIT_PARAM

public static final String BINARY_DATA_PROP_NAME_INIT_PARAM

See Also:

Constant Field Values

BINARY_MIME_TYPE_PROP_NAME_INIT_PARAM

public static final String BINARY_MIME_TYPE_PROP_NAME_INIT_PARAM

See Also:

Constant Field Values

BINARY_LAST_MODIFIED_PROP_NAME_INIT_PARAM

public static final String BINARY_LAST_MODIFIED_PROP_NAME_INIT_PARAM

See Also:

Constant Field Values

Constructor Detail

BinariesServlet

public BinariesServlet()

Method Detail

createBinaryPageFactory

protected BinaryPageFactory createBinaryPageFactory()

init

public void init(javax.servlet.ServletConfig config)
          throws javax.servlet.ServletException

Specified by:

init in interface javax.servlet.Servlet

Overrides:

init in class javax.servlet.GenericServlet

Throws:

javax.servlet.ServletException

doGet

public void doGet(javax.servlet.http.HttpServletRequest request,
                  javax.servlet.http.HttpServletResponse response)
           throws javax.servlet.ServletException,
                  IOException

Overrides:

doGet in class javax.servlet.http.HttpServlet

Throws:

javax.servlet.ServletException

IOException

writeResponse

protected void writeResponse(javax.servlet.http.HttpServletRequest request,
                             javax.servlet.http.HttpServletResponse response,
                             BinaryPage page)
                      throws IOException

Throws:

IOException

getRepositoryResourceStream

protected InputStream getRepositoryResourceStream(javax.jcr.Session session,
                                                  BinaryPage page)
                                           throws javax.jcr.RepositoryException

Parameters:

session -

page -

Returns:

the input stream for a looked up binary for BinaryPage.getResourcePath(), or null if no binary could be found.

Throws:

javax.jcr.RepositoryException

getPageFromCacheOrLoadPage

protected BinaryPage getPageFromCacheOrLoadPage(javax.servlet.http.HttpServletRequest request)

getValidatedPageFromCache

protected BinaryPage getValidatedPageFromCache(javax.servlet.http.HttpServletRequest request,
                                               BinaryPage page)

isPageStale

protected boolean isPageStale(javax.servlet.http.HttpServletRequest request,
                              BinaryPage page)

Hook for subclasses to check whether a previously cached page should be recreated. The default implementation in this BinariesServlet returns false

Parameters:

request - current HTTP request

page - current cached binary page

Returns:

true if the page should be recreated, false otherwise

getLastModifiedFromResource

protected long getLastModifiedFromResource(javax.servlet.http.HttpServletRequest request,
                                           String resourcePath)

getSessionUserID

protected final String getSessionUserID(javax.servlet.http.HttpServletRequest request)

getResourceNode

protected javax.jcr.Node getResourceNode(javax.jcr.Session session,
                                         String resourcePath)

Retrieve the JCR node representing a resource

Parameters:

session - the jcr session to fetch the resource with

resourcePath - path of resource

Returns:

resource node if found, or null if cannot be found or a RepositoryException happened.

getBinaryPage

protected BinaryPage getBinaryPage(javax.servlet.http.HttpServletRequest request,
                                   String resourcePath)

initBinaryPageValues

protected void initBinaryPageValues(javax.jcr.Session session,
                                    BinaryPage page)
                             throws javax.jcr.RepositoryException

Throws:

javax.jcr.RepositoryException

storeResourceOnBinaryPage

protected void storeResourceOnBinaryPage(BinaryPage page,
                                         javax.jcr.Node resourceNode)

Stores the binary content of resourceNode on the page unless the page is marked to be uncacheable.

doInit

protected void doInit()

getInitParameter

protected String getInitParameter(String paramName,
                                  String defaultValue)

getBooleanInitParameter

protected boolean getBooleanInitParameter(String paramName,
                                          boolean defaultValue)

getLongInitParameter

protected long getLongInitParameter(String paramName,
                                    long defaultValue)