Class PageContextImpl
- Author:
- Anil K. Vijendran, Larry Cable, Hans Bergsten, Pierre Delisle, Mark Roth, Jan Luehe, Jacob Hookom
-
Field Summary
Fields inherited from class jakarta.servlet.jsp.PageContext
APPLICATION, APPLICATION_SCOPE, CONFIG, EXCEPTION, OUT, PAGE, PAGE_SCOPE, PAGECONTEXT, REQUEST, REQUEST_SCOPE, RESPONSE, SESSION, SESSION_SCOPE -
Method Summary
Modifier and TypeMethodDescriptionfindAttribute(String name) Searches for the named attribute in page, request, session (if valid), and application scope(s) in order and returns the value associated or null.voidThis method is used to re-direct, or "forward" the current ServletRequest and ServletResponse to another active component in the application.getAttribute(String name) Returns the object associated with the name in the page scope or null if not found.getAttribute(String name, int scope) Return the object associated with the name in the specified scope or null if not found.getAttributeNamesInScope(int scope) Enumerate all the attributes in a given scope.intgetAttributesScope(String name) Get the scope where a given attribute is defined.Obtain the ELContext for this JSPContext.Returns the exception associated with this page context, if any.getOut()The current value of the out object (a JspWriter).getPage()The current value of the page object (In a Servlet environment, this is an instance of jakarta.servlet.Servlet).The current value of the request object (a ServletRequest).The current value of the response object (a ServletResponse).The ServletConfig instance.The ServletContext instance.The current value of the session object (an HttpSession).voidThis method is intended to process an unhandled 'page' level exception by forwarding the exception to the specified error page for this JSP.voidThis method is intended to process an unhandled 'page' level exception by forwarding the exception to the specified error page for this JSP.voidCauses the resource specified to be processed as part of the current ServletRequest and ServletResponse being processed by the calling Thread.voidCauses the resource specified to be processed as part of the current ServletRequest and ServletResponse being processed by the calling Thread.voidinitialize(Servlet servlet, ServletRequest request, ServletResponse response, String errorPageURL, boolean needsSession, int bufferSize, boolean autoFlush) The initialize method is called to initialize an uninitialized PageContext so that it may be used by a JSP Implementation class to service an incoming request and response within it's _jspService() method.popBody()Return the previous JspWriter "out" saved by the matching pushBody(), and update the value of the "out" attribute in the page scope attribute namespace of the JspContext.static ObjectproprietaryEvaluate(String expression, Class<?> expectedType, PageContext pageContext, ProtectedFunctionMapper functionMap) Proprietary method to evaluate EL expressions.pushBody()Return a new BodyContent object, save the current "out" JspWriter, and update the value of the "out" attribute in the page scope attribute namespace of the PageContext.Return a new JspWriter object that sends output to the provided Writer.voidrelease()This method shall "reset" the internal state of a PageContext, releasing all internal references, and preparing the PageContext for potential reuse by a later invocation of initialize().voidremoveAttribute(String name) Remove the object reference associated with the given name from all scopes.voidremoveAttribute(String name, int scope) Remove the object reference associated with the specified name in the given scope.voidsetAttribute(String name, Object attribute) Register the name and value specified with page scope semantics.voidsetAttribute(String name, Object o, int scope) Register the name and value specified with appropriate scope semantics.Methods inherited from class jakarta.servlet.jsp.PageContext
getErrorData
-
Method Details
-
initialize
public void initialize(Servlet servlet, ServletRequest request, ServletResponse response, String errorPageURL, boolean needsSession, int bufferSize, boolean autoFlush) throws IOException Description copied from class:jakarta.servlet.jsp.PageContextThe initialize method is called to initialize an uninitialized PageContext so that it may be used by a JSP Implementation class to service an incoming request and response within it's _jspService() method.
This method is typically called from JspFactory.getPageContext() in order to initialize state.
This method is required to create an initial JspWriter, and associate the "out" name in page scope with this newly created object.
This method should not be used by page or tag library authors.
- Specified by:
initializein classPageContext- Parameters:
servlet- The Servlet that is associated with this PageContextrequest- The currently pending request for this Servletresponse- The currently pending response for this ServleterrorPageURL- The value of the errorpage attribute from the page directive or nullneedsSession- The value of the session attribute from the page directivebufferSize- The value of the buffer attribute from the page directiveautoFlush- The value of the autoflush attribute from the page directive- Throws:
IOException- during creation of JspWriter
-
release
public void release()Description copied from class:jakarta.servlet.jsp.PageContextThis method shall "reset" the internal state of a PageContext, releasing all internal references, and preparing the PageContext for potential reuse by a later invocation of initialize(). This method is typically called from JspFactory.releasePageContext().
Subclasses shall override this method.
This method should not be used by page or tag library authors.
- Specified by:
releasein classPageContext
-
getAttribute
Description copied from class:jakarta.servlet.jsp.JspContextReturns the object associated with the name in the page scope or null if not found.- Specified by:
getAttributein classJspContext- Parameters:
name- the name of the attribute to get- Returns:
- the object associated with the name in the page scope or null if not found.
-
getAttribute
Description copied from class:jakarta.servlet.jsp.JspContextReturn the object associated with the name in the specified scope or null if not found.- Specified by:
getAttributein classJspContext- Parameters:
name- the name of the attribute to setscope- the scope with which to associate the name/object- Returns:
- the object associated with the name in the specified scope or null if not found.
-
setAttribute
Description copied from class:jakarta.servlet.jsp.JspContextRegister the name and value specified with page scope semantics. If the value passed in isnull, this has the same effect as callingremoveAttribute( name, PageContext.PAGE_SCOPE ).- Specified by:
setAttributein classJspContext- Parameters:
name- the name of the attribute to setattribute- the value to associate with the name, or null if the attribute is to be removed from the page scope.
-
setAttribute
Description copied from class:jakarta.servlet.jsp.JspContextRegister the name and value specified with appropriate scope semantics. If the value passed in isnull, this has the same effect as callingremoveAttribute( name, scope ).- Specified by:
setAttributein classJspContext- Parameters:
name- the name of the attribute to seto- the object to associate with the name, or null if the attribute is to be removed from the specified scope.scope- the scope with which to associate the name/object
-
removeAttribute
Description copied from class:jakarta.servlet.jsp.JspContextRemove the object reference associated with the specified name in the given scope. Does nothing if there is no such object.- Specified by:
removeAttributein classJspContext- Parameters:
name- The name of the object to remove.scope- The scope where to look.
-
getAttributesScope
Description copied from class:jakarta.servlet.jsp.JspContextGet the scope where a given attribute is defined.- Specified by:
getAttributesScopein classJspContext- Parameters:
name- the name of the attribute to return the scope for- Returns:
- the scope of the object associated with the name specified or 0
-
findAttribute
Description copied from class:jakarta.servlet.jsp.JspContextSearches for the named attribute in page, request, session (if valid), and application scope(s) in order and returns the value associated or null.- Specified by:
findAttributein classJspContext- Parameters:
name- the name of the attribute to search for- Returns:
- the value associated or null
-
getAttributeNamesInScope
Description copied from class:jakarta.servlet.jsp.JspContextEnumerate all the attributes in a given scope.- Specified by:
getAttributeNamesInScopein classJspContext- Parameters:
scope- the scope to enumerate all the attributes for- Returns:
- an enumeration of names (
String) of all the attributes the specified scope
-
removeAttribute
Description copied from class:jakarta.servlet.jsp.JspContextRemove the object reference associated with the given name from all scopes. Does nothing if there is no such object.- Specified by:
removeAttributein classJspContext- Parameters:
name- The name of the object to remove.
-
getOut
Description copied from class:jakarta.servlet.jsp.JspContextThe current value of the out object (a JspWriter).- Specified by:
getOutin classJspContext- Returns:
- the current JspWriter stream being used for client response
-
getSession
Description copied from class:jakarta.servlet.jsp.PageContextThe current value of the session object (an HttpSession).- Specified by:
getSessionin classPageContext- Returns:
- the HttpSession for this PageContext or null
-
getServletConfig
Description copied from class:jakarta.servlet.jsp.PageContextThe ServletConfig instance.- Specified by:
getServletConfigin classPageContext- Returns:
- the ServletConfig for this PageContext
-
getServletContext
Description copied from class:jakarta.servlet.jsp.PageContextThe ServletContext instance.- Specified by:
getServletContextin classPageContext- Returns:
- the ServletContext for this PageContext
-
getRequest
Description copied from class:jakarta.servlet.jsp.PageContextThe current value of the request object (a ServletRequest).- Specified by:
getRequestin classPageContext- Returns:
- The ServletRequest for this PageContext
-
getResponse
Description copied from class:jakarta.servlet.jsp.PageContextThe current value of the response object (a ServletResponse).- Specified by:
getResponsein classPageContext- Returns:
- the ServletResponse for this PageContext
-
getException
Returns the exception associated with this page context, if any.Added wrapping for Throwables to avoid ClassCastException: see Bugzilla 31171 for details.
- Specified by:
getExceptionin classPageContext- Returns:
- The Exception associated with this page context, if any.
-
getPage
Description copied from class:jakarta.servlet.jsp.PageContextThe current value of the page object (In a Servlet environment, this is an instance of jakarta.servlet.Servlet).- Specified by:
getPagein classPageContext- Returns:
- the Page implementation class instance associated with this PageContext
-
include
Description copied from class:jakarta.servlet.jsp.PageContextCauses the resource specified to be processed as part of the current ServletRequest and ServletResponse being processed by the calling Thread. The output of the target resources processing of the request is written directly to the ServletResponse output stream.
The current JspWriter "out" for this JSP is flushed as a side effect of this call, prior to processing the include.
If the relativeUrlPath begins with a "/" then the URL specified is calculated relative to the DOCROOT of the
ServletContextfor this JSP. If the path does not begin with a "/" then the URL specified is calculated relative to the URL of the request that was mapped to the calling JSP.It is only valid to call this method from a
Threadexecuting within a_jspService(...)method of a JSP.- Specified by:
includein classPageContext- Parameters:
relativeUrlPath- specifies the relative URL path to the target resource to be included- Throws:
ServletException- if the page that was forwarded to throws a ServletExceptionIOException- if an I/O error occurred while forwarding
-
include
Description copied from class:jakarta.servlet.jsp.PageContextCauses the resource specified to be processed as part of the current ServletRequest and ServletResponse being processed by the calling Thread. The output of the target resources processing of the request is written directly to the current JspWriter returned by a call to getOut().
If flush is true, The current JspWriter "out" for this JSP is flushed as a side effect of this call, prior to processing the include. Otherwise, the JspWriter "out" is not flushed.
If the relativeUrlPath begins with a "/" then the URL specified is calculated relative to the DOCROOT of the
ServletContextfor this JSP. If the path does not begin with a "/" then the URL specified is calculated relative to the URL of the request that was mapped to the calling JSP.It is only valid to call this method from a
Threadexecuting within a_jspService(...)method of a JSP.- Specified by:
includein classPageContext- Parameters:
relativeUrlPath- specifies the relative URL path to the target resource to be includedflush- True if the JspWriter is to be flushed before the include, or false if not.- Throws:
ServletException- if the page that was forwarded to throws a ServletExceptionIOException- if an I/O error occurred while forwarding
-
forward
Description copied from class:jakarta.servlet.jsp.PageContextThis method is used to re-direct, or "forward" the current ServletRequest and ServletResponse to another active component in the application.
If the relativeUrlPath begins with a "/" then the URL specified is calculated relative to the DOCROOT of the
ServletContextfor this JSP. If the path does not begin with a "/" then the URL specified is calculated relative to the URL of the request that was mapped to the calling JSP.It is only valid to call this method from a
Threadexecuting within a_jspService(...)method of a JSP.Once this method has been called successfully, it is illegal for the calling
Threadto attempt to modify theServletResponseobject. Any such attempt to do so, shall result in undefined behavior. Typically, callers immediately return from_jspService(...)after calling this method.- Specified by:
forwardin classPageContext- Parameters:
relativeUrlPath- specifies the relative URL path to the target resource as described above- Throws:
ServletException- if the page that was forwarded to throws a ServletExceptionIOException- if an I/O error occurred while forwarding
-
pushBody
Description copied from class:jakarta.servlet.jsp.PageContextReturn a new BodyContent object, save the current "out" JspWriter, and update the value of the "out" attribute in the page scope attribute namespace of the PageContext.- Overrides:
pushBodyin classPageContext- Returns:
- the new BodyContent
-
pushBody
Description copied from class:jakarta.servlet.jsp.JspContextReturn a new JspWriter object that sends output to the provided Writer. Saves the current "out" JspWriter, and updates the value of the "out" attribute in the page scope attribute namespace of the JspContext.The returned JspWriter must implement all methods and behave as though it were unbuffered. More specifically:
- clear() must throw an IOException
- clearBuffer() does nothing
- getBufferSize() always returns 0
- getRemaining() always returns 0
- Overrides:
pushBodyin classJspContext- Parameters:
writer- The Writer for the returned JspWriter to send output to.- Returns:
- a new JspWriter that writes to the given Writer.
-
popBody
Description copied from class:jakarta.servlet.jsp.JspContextReturn the previous JspWriter "out" saved by the matching pushBody(), and update the value of the "out" attribute in the page scope attribute namespace of the JspContext.- Overrides:
popBodyin classJspContext- Returns:
- the saved JspWriter.
-
handlePageException
Description copied from class:jakarta.servlet.jsp.PageContextThis method is intended to process an unhandled 'page' level exception by forwarding the exception to the specified error page for this JSP. If forwarding is not possible (for example because the response has already been committed), an implementation dependent mechanism should be used to invoke the error page (e.g. "including" the error page instead).
If no error page is defined in the page, the exception should be rethrown so that the standard servlet error handling takes over.
A JSP implementation class shall typically clean up any local state prior to invoking this and will return immediately thereafter. It is illegal to generate any output to the client, or to modify any ServletResponse state after invoking this call.
This method is kept for backwards compatibility reasons. Newly generated code should use PageContext.handlePageException(Throwable).
- Specified by:
handlePageExceptionin classPageContext- Parameters:
ex- the exception to be handled- Throws:
IOException- if an I/O error occurred while invoking the error pageServletException- if an error occurs while invoking the error page- See Also:
-
handlePageException
Description copied from class:jakarta.servlet.jsp.PageContextThis method is intended to process an unhandled 'page' level exception by forwarding the exception to the specified error page for this JSP. If forwarding is not possible (for example because the response has already been committed), an implementation dependent mechanism should be used to invoke the error page (e.g. "including" the error page instead).
If no error page is defined in the page, the exception should be rethrown so that the standard servlet error handling takes over.
This method is intended to process an unhandled "page" level exception by redirecting the exception to either the specified error page for this JSP, or if none was specified, to perform some implementation dependent action.
A JSP implementation class shall typically clean up any local state prior to invoking this and will return immediately thereafter. It is illegal to generate any output to the client, or to modify any ServletResponse state after invoking this call.
- Specified by:
handlePageExceptionin classPageContext- Parameters:
t- the throwable to be handled- Throws:
IOException- if an I/O error occurred while invoking the error pageServletException- if an error occurs while invoking the error page- See Also:
-
proprietaryEvaluate
public static Object proprietaryEvaluate(String expression, Class<?> expectedType, PageContext pageContext, ProtectedFunctionMapper functionMap) throws ELException Proprietary method to evaluate EL expressions. XXX - This method should go away once the EL interpreter moves out of JSTL and into its own project. For now, this is necessary because the standard machinery is too slow.- Parameters:
expression- The expression to be evaluatedexpectedType- The expected resulting typepageContext- The page contextfunctionMap- Maps prefix and name to Method- Returns:
- The result of the evaluation
- Throws:
ELException- If an error occurs during the evaluation
-
getELContext
Description copied from class:jakarta.servlet.jsp.JspContextObtain the ELContext for this JSPContext. Each JSPContext has a dedicated ELContext.- Specified by:
getELContextin classJspContext- Returns:
- the ELContext for this JSPContext
-