Package org.apache.velocity.servlet
Class VelocityServlet
java.lang.Object
javax.servlet.GenericServlet
javax.servlet.http.HttpServlet
org.apache.velocity.servlet.VelocityServlet
- All Implemented Interfaces:
Serializable
,javax.servlet.Servlet
,javax.servlet.ServletConfig
public abstract class VelocityServlet
extends javax.servlet.http.HttpServlet
Deprecated.
This servlet has been replaced by VelocityViewServlet,
available from the Velocity-Tools sub-project. VelocityViewServlet
provides support for quick, clean MVC web development.
VelocityServlet will be removed in a future version of Velocity.
Base class which simplifies the use of Velocity with Servlets.
Extend this class, implement the
If you put a String with key "contentType" object into the context within either your servlet or within your template, then that will be used to override the default content type specified in the properties file.
handleRequest()
method,
and add your data to the context. Then call
getTemplate("myTemplate.wm")
.
This class puts some things into the context object that you should
be aware of:
"req" - The HttpServletRequest object "res" - The HttpServletResponse objectThere are other methods you can override to access, alter or control any part of the request processing chain. Please see the javadocs for more information on :
- loadConfiguration() : for setting up the Velocity runtime
- createContext() : for creating and loading the Context
- setContentType() : for changing the content type on a request by request basis
- handleRequest() : you must implement this
- mergeTemplate() : the template rendering process
- requestCleanup() : post rendering resource or other cleanup
- error() : error handling
If you put a String with key "contentType" object into the context within either your servlet or within your template, then that will be used to override the default content type specified in the properties file.
- Author:
- Dave Bryson, Jon S. Stevens, Geir Magnusson Jr., Kent Johnson, Daniel Rall $Id: VelocityServlet.java 463298 2006-10-12 16:10:32Z henning $
- See Also:
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Field Summary
FieldsModifier and TypeFieldDescriptionstatic final String
Deprecated.The HTTP content type context key.static final String
Deprecated.The default content type for the responsestatic final String
Deprecated.Encoding for the output streamprotected static final String
Deprecated.This is the string that is looked for when getInitParameter is called (org.apache.velocity.properties
).static final String
Deprecated.The context key for the HTTP request object.static final String
Deprecated.The context key for the HTTP response object. -
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionprotected String
chooseCharacterEncoding
(javax.servlet.http.HttpServletRequest request) Deprecated.Chooses the output character encoding to be used as the value for the "charset=" portion of the HTTP Content-Type header (and thus returned byresponse.getCharacterEncoding()
).protected Context
createContext
(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) Deprecated.Returns a context suitable to pass to the handleRequest() method
Default implementation will create a VelocityContext object, put the HttpServletRequest and HttpServletResponse into the context accessable via the keys VelocityServlet.REQUEST and VelocityServlet.RESPONSE, respectively.void
doGet
(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) Deprecated.Handles HTTPGET
requests by callingdoRequest(HttpServletRequest, HttpServletResponse)
.void
doPost
(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) Deprecated.Handles HTTPPOST
requests by callingdoRequest(HttpServletRequest, HttpServletResponse)
.protected void
doRequest
(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) Deprecated.Handles all requests (by default).protected void
error
(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, Exception cause) Deprecated.Invoked when there is an error thrown in any part of doRequest() processing.getTemplate
(String name) Deprecated.Retrieves the requested template.getTemplate
(String name, String encoding) Deprecated.Retrieves the requested template with the specified character encoding.protected Template
handleRequest
(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, Context ctx) Deprecated.Implement this method to add your application data to the context, calling thegetTemplate()
method to produce your return value.protected Template
handleRequest
(Context ctx) void
init
(javax.servlet.ServletConfig config) Deprecated.Performs initialization of this servlet.protected void
initVelocity
(javax.servlet.ServletConfig config) Deprecated.Initializes the Velocity runtime, first calling loadConfiguration(ServletConvig) to get a java.util.Properties of configuration information and then calling Velocity.init().protected Properties
loadConfiguration
(javax.servlet.ServletConfig config) Deprecated.Use VelocityViewServlet from the Velocity Tools library instead.protected void
mergeTemplate
(Template template, Context context, javax.servlet.http.HttpServletResponse response) Deprecated.merges the template with the context.protected void
requestCleanup
(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, Context context) Deprecated.A cleanup routine which is called at the end of thedoRequest(HttpServletRequest, HttpServletResponse)
processing sequence, allowing a derived class to do resource cleanup or other end of process cycle tasks.protected void
setContentType
(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) Deprecated.Sets the content type of the response, defaulting todefaultContentType
if not overriden.Methods inherited from class javax.servlet.http.HttpServlet
doDelete, doHead, doOptions, doPut, doTrace, getLastModified, service, service
Methods inherited from class javax.servlet.GenericServlet
destroy, getInitParameter, getInitParameterNames, getServletConfig, getServletContext, getServletInfo, getServletName, init, log, log
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Field Details
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REQUEST
Deprecated.The context key for the HTTP request object.- See Also:
-
RESPONSE
Deprecated.The context key for the HTTP response object.- See Also:
-
CONTENT_TYPE
Deprecated.The HTTP content type context key.- See Also:
-
DEFAULT_CONTENT_TYPE
Deprecated.The default content type for the response- See Also:
-
DEFAULT_OUTPUT_ENCODING
Deprecated.Encoding for the output stream- See Also:
-
INIT_PROPS_KEY
Deprecated.This is the string that is looked for when getInitParameter is called (org.apache.velocity.properties
).- See Also:
-
-
Constructor Details
-
VelocityServlet
public VelocityServlet()Deprecated.
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-
Method Details
-
init
public void init(javax.servlet.ServletConfig config) throws javax.servlet.ServletException Deprecated.Performs initialization of this servlet. Called by the servlet container on loading.- Specified by:
init
in interfacejavax.servlet.Servlet
- Overrides:
init
in classjavax.servlet.GenericServlet
- Parameters:
config
- The servlet configuration to apply.- Throws:
javax.servlet.ServletException
-
initVelocity
protected void initVelocity(javax.servlet.ServletConfig config) throws javax.servlet.ServletException Deprecated.Initializes the Velocity runtime, first calling loadConfiguration(ServletConvig) to get a java.util.Properties of configuration information and then calling Velocity.init(). Override this to do anything to the environment before the initialization of the singelton takes place, or to initialize the singleton in other ways.- Parameters:
config
-- Throws:
javax.servlet.ServletException
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loadConfiguration
protected Properties loadConfiguration(javax.servlet.ServletConfig config) throws IOException, FileNotFoundException Deprecated.Use VelocityViewServlet from the Velocity Tools library instead.Loads the configuration information and returns that information as a Properties, which will be used to initialize the Velocity runtime.
Currently, this method gets the initialization parameter VelocityServlet.INIT_PROPS_KEY, which should be a file containing the configuration information.
To configure your Servlet Spec 2.2 compliant servlet runner to pass this to you, put the following in your WEB-INF/web.xml file
<servlet> <servlet-name> YourServlet </servlet-name> <servlet-class> your.package.YourServlet </servlet-class> <init-param> <param-name> org.apache.velocity.properties </param-name> <param-value> velocity.properties </param-value> </init-param> </servlet>
Alternately, if you wish to configure an entire context in this fashion, you may use the following:
<context-param> <param-name> org.apache.velocity.properties </param-name> <param-value> velocity.properties </param-value> <description> Path to Velocity configuration </description> </context-param>
Derived classes may do the same, or take advantage of this code to do the loading for them via :Properties p = super.loadConfiguration( config );
and then add or modify the configuration values from the file.- Parameters:
config
- ServletConfig passed to the servlets init() function Can be used to access the real path via ServletContext (hint)- Returns:
- java.util.Properties loaded with configuration values to be used to initialize the Velocity runtime.
- Throws:
FileNotFoundException
- if a specified file is not found.IOException
- I/O problem accessing the specified file, if specified.
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doGet
public void doGet(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) throws javax.servlet.ServletException, IOException Deprecated.Handles HTTPGET
requests by callingdoRequest(HttpServletRequest, HttpServletResponse)
.- Overrides:
doGet
in classjavax.servlet.http.HttpServlet
- Parameters:
request
-response
-- Throws:
javax.servlet.ServletException
IOException
-
doPost
public void doPost(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) throws javax.servlet.ServletException, IOException Deprecated.Handles HTTPPOST
requests by callingdoRequest(HttpServletRequest, HttpServletResponse)
.- Overrides:
doPost
in classjavax.servlet.http.HttpServlet
- Parameters:
request
-response
-- Throws:
javax.servlet.ServletException
IOException
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doRequest
protected void doRequest(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) throws javax.servlet.ServletException, IOException Deprecated.Handles all requests (by default).- Parameters:
request
- HttpServletRequest object containing client requestresponse
- HttpServletResponse object for the response- Throws:
javax.servlet.ServletException
IOException
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requestCleanup
protected void requestCleanup(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, Context context) Deprecated.A cleanup routine which is called at the end of thedoRequest(HttpServletRequest, HttpServletResponse)
processing sequence, allowing a derived class to do resource cleanup or other end of process cycle tasks.- Parameters:
request
- servlet request from clientresponse
- servlet reponsecontext
- context created by the createContext() method
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mergeTemplate
protected void mergeTemplate(Template template, Context context, javax.servlet.http.HttpServletResponse response) throws ResourceNotFoundException, ParseErrorException, MethodInvocationException, IOException, UnsupportedEncodingException, Exception Deprecated.merges the template with the context. Only override this if you really, really really need to. (And don't call us with questions if it breaks :)- Parameters:
template
- template object returned by the handleRequest() methodcontext
- context created by the createContext() methodresponse
- servlet reponse (use this to get the output stream or Writer- Throws:
ResourceNotFoundException
ParseErrorException
MethodInvocationException
IOException
UnsupportedEncodingException
Exception
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setContentType
protected void setContentType(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) Deprecated.Sets the content type of the response, defaulting todefaultContentType
if not overriden. Delegates tochooseCharacterEncoding(HttpServletRequest)
to select the appropriate character encoding.- Parameters:
request
- The servlet request from the client.response
- The servlet reponse to the client.
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chooseCharacterEncoding
Deprecated.Chooses the output character encoding to be used as the value for the "charset=" portion of the HTTP Content-Type header (and thus returned byresponse.getCharacterEncoding()
). Called bysetContentType(HttpServletRequest, HttpServletResponse)
if an encoding isn't already specified by Content-Type. By default, chooses the value of RuntimeSingleton'soutput.encoding
property.- Parameters:
request
- The servlet request from the client.- Returns:
- The chosen character encoding.
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createContext
protected Context createContext(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) Deprecated.Returns a context suitable to pass to the handleRequest() method
Default implementation will create a VelocityContext object, put the HttpServletRequest and HttpServletResponse into the context accessable via the keys VelocityServlet.REQUEST and VelocityServlet.RESPONSE, respectively.- Parameters:
request
- servlet request from clientresponse
- servlet reponse to client- Returns:
- context
-
getTemplate
public Template getTemplate(String name) throws ResourceNotFoundException, ParseErrorException, Exception Deprecated.Retrieves the requested template.- Parameters:
name
- The file name of the template to retrieve relative to the template root.- Returns:
- The requested template.
- Throws:
ResourceNotFoundException
- if template not found from any available source.ParseErrorException
- if template cannot be parsed due to syntax (or other) error.Exception
- if an error occurs in template initialization
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getTemplate
public Template getTemplate(String name, String encoding) throws ResourceNotFoundException, ParseErrorException, Exception Deprecated.Retrieves the requested template with the specified character encoding.- Parameters:
name
- The file name of the template to retrieve relative to the template root.encoding
- the character encoding of the template- Returns:
- The requested template.
- Throws:
ResourceNotFoundException
- if template not found from any available source.ParseErrorException
- if template cannot be parsed due to syntax (or other) error.Exception
- if an error occurs in template initialization- Since:
- Velocity v1.1
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handleRequest
protected Template handleRequest(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, Context ctx) throws Exception Deprecated.Implement this method to add your application data to the context, calling thegetTemplate()
method to produce your return value.
In the event of a problem, you may handle the request directly and returnnull
or throw a more meaningful exception for the error handler to catch.- Parameters:
request
- servlet request from clientresponse
- servlet reponsectx
- The context to add your data to.- Returns:
- The template to merge with your context or null, indicating that you handled the processing.
- Throws:
Exception
- Since:
- Velocity v1.1
-
handleRequest
Deprecated.Implement this method to add your application data to the context, calling thegetTemplate()
method to produce your return value.
In the event of a problem, you may simple returnnull
or throw a more meaningful exception.- Parameters:
ctx
- The context to add your data to.- Returns:
- The template to merge with your context.
- Throws:
Exception
-
error
protected void error(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, Exception cause) throws javax.servlet.ServletException, IOException Deprecated.Invoked when there is an error thrown in any part of doRequest() processing.
Default will send a simple HTML response indicating there was a problem.- Parameters:
request
- original HttpServletRequest from servlet container.response
- HttpServletResponse object from servlet container.cause
- Exception that was thrown by some other part of process.- Throws:
javax.servlet.ServletException
IOException
-