bboss.org.apache.velocity.servlet

类 VelocityServlet

java.lang.Object

javax.servlet.GenericServlet

javax.servlet.http.HttpServlet

bboss.org.apache.velocity.servlet.VelocityServlet

所有已实现的接口:

java.io.Serializable, javax.servlet.Servlet, javax.servlet.ServletConfig

已过时。

This servlet has been replaced by VelocityViewServlet, available from the Velocity-Tools sub-project.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.

public abstract class VelocityServlet
extends javax.servlet.http.HttpServlet

Base class which simplifies the use of Velocity with Servlets. Extend this class, implement the 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 object
 

There 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.

另请参阅:

序列化表格

字段概要

字段

限定符和类型	字段和说明
static java.lang.String	CONTENT_TYPE 已过时。 The HTTP content type context key.
static java.lang.String	DEFAULT_CONTENT_TYPE 已过时。 The default content type for the response
static java.lang.String	DEFAULT_OUTPUT_ENCODING 已过时。 Encoding for the output stream
protected static java.lang.String	INIT_PROPS_KEY 已过时。 This is the string that is looked for when getInitParameter is called (bboss.org.apache.velocity.properties).
static java.lang.String	REQUEST 已过时。 The context key for the HTTP request object.
static java.lang.String	RESPONSE 已过时。 The context key for the HTTP response object.

构造器概要

构造器

构造器和说明
VelocityServlet() 已过时。

方法概要

限定符和类型	方法和说明
protected java.lang.String	chooseCharacterEncoding(javax.servlet.http.HttpServletRequest request) 已过时。 Chooses the output character encoding to be used as the value for the "charset=" portion of the HTTP Content-Type header (and thus returned by response.getCharacterEncoding()).
protected Context	createContext(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) 已过时。 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) 已过时。 Handles HTTP GET requests by calling doRequest(HttpServletRequest, HttpServletResponse).
void	doPost(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) 已过时。 Handles HTTP POST requests by calling doRequest(HttpServletRequest, HttpServletResponse).
protected void	doRequest(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) 已过时。 Handles all requests (by default).
protected void	error(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, java.lang.Exception cause) 已过时。 Invoked when there is an error thrown in any part of doRequest() processing.
Template	getTemplate(java.lang.String name) 已过时。 Retrieves the requested template.
Template	getTemplate(java.lang.String name, java.lang.String encoding) 已过时。 Retrieves the requested template with the specified character encoding.
protected Template	handleRequest(Context ctx) 已过时。 Use handleRequest( HttpServletRequest request, HttpServletResponse response, Context ctx )
protected Template	handleRequest(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, Context ctx) 已过时。 Implement this method to add your application data to the context, calling the getTemplate() method to produce your return value.
void	init(javax.servlet.ServletConfig config) 已过时。 Performs initialization of this servlet.
protected void	initVelocity(javax.servlet.ServletConfig config) 已过时。 Initializes the Velocity runtime, first calling loadConfiguration(ServletConvig) to get a java.util.Properties of configuration information and then calling Velocity.init().
protected java.util.Properties	loadConfiguration(javax.servlet.ServletConfig config) 已过时。 Use VelocityViewServlet from the Velocity Tools library instead.
protected void	mergeTemplate(Template template, Context context, javax.servlet.http.HttpServletResponse response) 已过时。 merges the template with the context.
protected void	requestCleanup(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, Context context) 已过时。 A cleanup routine which is called at the end of the doRequest(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) 已过时。 Sets the content type of the response, defaulting to defaultContentType if not overriden.

从类继承的方法 javax.servlet.http.HttpServlet

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

从类继承的方法 javax.servlet.GenericServlet

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

从类继承的方法 java.lang.Object

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

字段详细资料

REQUEST

public static final java.lang.String REQUEST

已过时。

The context key for the HTTP request object.

另请参阅:

常量字段值

RESPONSE

public static final java.lang.String RESPONSE

已过时。

The context key for the HTTP response object.

另请参阅:

常量字段值

CONTENT_TYPE

public static final java.lang.String CONTENT_TYPE

已过时。

The HTTP content type context key.

另请参阅:

常量字段值

DEFAULT_CONTENT_TYPE

public static final java.lang.String DEFAULT_CONTENT_TYPE

已过时。

The default content type for the response

另请参阅:

常量字段值

DEFAULT_OUTPUT_ENCODING

public static final java.lang.String DEFAULT_OUTPUT_ENCODING

已过时。

Encoding for the output stream

另请参阅:

常量字段值

INIT_PROPS_KEY

protected static final java.lang.String INIT_PROPS_KEY

已过时。

This is the string that is looked for when getInitParameter is called (bboss.org.apache.velocity.properties).

另请参阅:

常量字段值

构造器详细资料

VelocityServlet

public VelocityServlet()

已过时。

方法详细资料

init

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

已过时。

Performs initialization of this servlet. Called by the servlet container on loading.

指定者:

init 在接口中 javax.servlet.Servlet

覆盖:

init 在类中 javax.servlet.GenericServlet

参数:

config - The servlet configuration to apply.

抛出:

javax.servlet.ServletException

initVelocity

protected void initVelocity(javax.servlet.ServletConfig config)
                     throws javax.servlet.ServletException

已过时。

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.

参数:

config -

抛出:

javax.servlet.ServletException

loadConfiguration

protected java.util.Properties loadConfiguration(javax.servlet.ServletConfig config)
                                          throws java.io.IOException,
                                                 java.io.FileNotFoundException

已过时。 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> bboss.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> bboss.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.

参数:

config - ServletConfig passed to the servlets init() function Can be used to access the real path via ServletContext (hint)

返回:

java.util.Properties loaded with configuration values to be used to initialize the Velocity runtime.

抛出:

java.io.FileNotFoundException - if a specified file is not found.

java.io.IOException - I/O problem accessing the specified file, if specified.

doGet

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

已过时。

Handles HTTP GET requests by calling doRequest(HttpServletRequest, HttpServletResponse).

覆盖:

doGet 在类中 javax.servlet.http.HttpServlet

参数:

request -

response -

抛出:

javax.servlet.ServletException

java.io.IOException

doPost

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

已过时。

Handles HTTP POST requests by calling doRequest(HttpServletRequest, HttpServletResponse).

覆盖:

doPost 在类中 javax.servlet.http.HttpServlet

参数:

request -

response -

抛出:

javax.servlet.ServletException

java.io.IOException

doRequest

protected void doRequest(javax.servlet.http.HttpServletRequest request,
                         javax.servlet.http.HttpServletResponse response)
                  throws javax.servlet.ServletException,
                         java.io.IOException

已过时。

Handles all requests (by default).

参数:

request - HttpServletRequest object containing client request

response - HttpServletResponse object for the response

抛出:

javax.servlet.ServletException

java.io.IOException

requestCleanup

protected void requestCleanup(javax.servlet.http.HttpServletRequest request,
                              javax.servlet.http.HttpServletResponse response,
                              Context context)

已过时。

A cleanup routine which is called at the end of the doRequest(HttpServletRequest, HttpServletResponse) processing sequence, allowing a derived class to do resource cleanup or other end of process cycle tasks.

参数:

request - servlet request from client

response - servlet reponse

context - context created by the createContext() method

mergeTemplate

protected void mergeTemplate(Template template,
                             Context context,
                             javax.servlet.http.HttpServletResponse response)
                      throws ResourceNotFoundException,
                             ParseErrorException,
                             MethodInvocationException,
                             java.io.IOException,
                             java.io.UnsupportedEncodingException,
                             java.lang.Exception

已过时。

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 :)

参数:

template - template object returned by the handleRequest() method

context - context created by the createContext() method

response - servlet reponse (use this to get the output stream or Writer

抛出:

ResourceNotFoundException

ParseErrorException

MethodInvocationException

java.io.IOException

java.io.UnsupportedEncodingException

java.lang.Exception

setContentType

protected void setContentType(javax.servlet.http.HttpServletRequest request,
                              javax.servlet.http.HttpServletResponse response)

已过时。

Sets the content type of the response, defaulting to defaultContentType if not overriden. Delegates to chooseCharacterEncoding(HttpServletRequest) to select the appropriate character encoding.

参数:

request - The servlet request from the client.

response - The servlet reponse to the client.

chooseCharacterEncoding

protected java.lang.String chooseCharacterEncoding(javax.servlet.http.HttpServletRequest request)

已过时。

Chooses the output character encoding to be used as the value for the "charset=" portion of the HTTP Content-Type header (and thus returned by response.getCharacterEncoding()). Called by setContentType(HttpServletRequest, HttpServletResponse) if an encoding isn't already specified by Content-Type. By default, chooses the value of RuntimeSingleton's output.encoding property.

参数:

request - The servlet request from the client.

返回:

The chosen character encoding.

createContext

protected Context createContext(javax.servlet.http.HttpServletRequest request,
                                javax.servlet.http.HttpServletResponse response)

已过时。

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.

参数:

request - servlet request from client

response - servlet reponse to client

返回:

context

getTemplate

public Template getTemplate(java.lang.String name)
                     throws ResourceNotFoundException,
                            ParseErrorException,
                            java.lang.Exception

已过时。

Retrieves the requested template.

参数:

name - The file name of the template to retrieve relative to the template root.

返回:

The requested template.

抛出:

ResourceNotFoundException - if template not found from any available source.

ParseErrorException - if template cannot be parsed due to syntax (or other) error.

java.lang.Exception - if an error occurs in template initialization

getTemplate

public Template getTemplate(java.lang.String name,
                            java.lang.String encoding)
                     throws ResourceNotFoundException,
                            ParseErrorException,
                            java.lang.Exception

已过时。

Retrieves the requested template with the specified character encoding.

参数:

name - The file name of the template to retrieve relative to the template root.

encoding - the character encoding of the template

返回:

The requested template.

抛出:

ResourceNotFoundException - if template not found from any available source.

ParseErrorException - if template cannot be parsed due to syntax (or other) error.

java.lang.Exception - if an error occurs in template initialization

从以下版本开始:

Velocity v1.1

handleRequest

protected Template handleRequest(javax.servlet.http.HttpServletRequest request,
                                 javax.servlet.http.HttpServletResponse response,
                                 Context ctx)
                          throws java.lang.Exception

已过时。

Implement this method to add your application data to the context, calling the getTemplate() method to produce your return value.

In the event of a problem, you may handle the request directly and return null or throw a more meaningful exception for the error handler to catch.

参数:

request - servlet request from client

response - servlet reponse

ctx - The context to add your data to.

返回:

The template to merge with your context or null, indicating that you handled the processing.

抛出:

java.lang.Exception

从以下版本开始:

Velocity v1.1

handleRequest

protected Template handleRequest(Context ctx)
                          throws java.lang.Exception

已过时。 Use handleRequest( HttpServletRequest request, HttpServletResponse response, Context ctx )

Implement this method to add your application data to the context, calling the getTemplate() method to produce your return value.

In the event of a problem, you may simple return null or throw a more meaningful exception.

参数:

ctx - The context to add your data to.

返回:

The template to merge with your context.

抛出:

java.lang.Exception

error

protected void error(javax.servlet.http.HttpServletRequest request,
                     javax.servlet.http.HttpServletResponse response,
                     java.lang.Exception cause)
              throws javax.servlet.ServletException,
                     java.io.IOException

已过时。

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.

参数:

request - original HttpServletRequest from servlet container.

response - HttpServletResponse object from servlet container.

cause - Exception that was thrown by some other part of process.

抛出:

javax.servlet.ServletException

java.io.IOException