public class PageContextImpl extends PageContext
This is a "dummy" implementation of PageContext whose only purpose is to serve the attribute getter/setter API's.
APPLICATION, APPLICATION_SCOPE, CONFIG, EXCEPTION, OUT, PAGE, PAGE_SCOPE, PAGECONTEXT, REQUEST, REQUEST_SCOPE, RESPONSE, SESSION, SESSION_SCOPE
Constructor and Description |
---|
PageContextImpl()
Constructor
|
Modifier and Type | Method and Description |
---|---|
java.lang.Object |
findAttribute(java.lang.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.
|
void |
forward(java.lang.String path)
This method is used to re-direct, or "forward" the current ServletRequest and ServletResponse to another active
component in the application.
|
java.lang.Object |
getAttribute(java.lang.String name)
Returns the object associated with the name in the page scope or null if not found.
|
java.lang.Object |
getAttribute(java.lang.String name,
int scope)
Return the object associated with the name in the specified scope or null if not found.
|
java.util.Enumeration |
getAttributeNamesInScope(int scope)
Enumerate all the attributes in a given scope.
|
int |
getAttributesScope(java.lang.String name)
Get the scope where a given attribute is defined.
|
javax.el.ELContext |
getELContext()
Returns the
ELContext associated with this JspContext . |
java.lang.Exception |
getException()
The current value of the exception object (an Exception).
|
ExpressionEvaluator |
getExpressionEvaluator()
Provides programmatic access to the ExpressionEvaluator.
|
JspWriter |
getOut()
The current value of the out object (a JspWriter).
|
java.lang.Object |
getPage()
The current value of the page object (In a Servlet environment, this is an instance of javax.servlet.Servlet).
|
ServletRequest |
getRequest()
The current value of the request object (a ServletRequest).
|
ServletResponse |
getResponse()
The current value of the response object (a ServletResponse).
|
ServletConfig |
getServletConfig()
The ServletConfig instance.
|
ServletContext |
getServletContext()
The ServletContext instance.
|
HttpSession |
getSession()
The current value of the session object (an HttpSession).
|
VariableResolver |
getVariableResolver()
Returns an instance of a VariableResolver that provides access to the implicit objects specified in the JSP
specification using this JspContext as the context object.
|
void |
handlePageException(java.lang.Exception exc)
This method is intended to process an unhandled 'page' level exception by forwarding the exception to the
specified error page for this JSP.
|
void |
handlePageException(java.lang.Throwable exc)
This method is intended to process an unhandled 'page' level exception by forwarding the exception to the
specified error page for this JSP.
|
void |
include(java.lang.String path)
Causes the resource specified to be processed as part of the current ServletRequest and ServletResponse being
processed by the calling Thread.
|
void |
include(java.lang.String relativeUrlPath,
boolean flush)
Causes the resource specified to be processed as part of the current ServletRequest and ServletResponse being
processed by the calling Thread.
|
void |
initialize(Servlet servlet,
ServletRequest request,
ServletResponse response,
java.lang.String errorPageURL,
boolean needSession,
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.
|
void |
release()
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().
|
void |
removeAttribute(java.lang.String name)
Remove the object reference associated with the given name from all scopes.
|
void |
removeAttribute(java.lang.String name,
int scope)
Remove the object reference associated with the specified name in the given scope.
|
void |
setAttribute(java.lang.String name,
java.lang.Object attribute)
Register the name and value specified with page scope semantics.
|
void |
setAttribute(java.lang.String name,
java.lang.Object attribute,
int scope)
Register the name and value specified with appropriate scope semantics.
|
getErrorData, pushBody
popBody, pushBody
public void initialize(Servlet servlet, ServletRequest request, ServletResponse response, java.lang.String errorPageURL, boolean needSession, int bufferSize, boolean autoFlush)
PageContext
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.
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.
initialize
in class PageContext
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 nullneedSession
- 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 directivepublic void release()
PageContext
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(). This method is typically called from JspFactory.releasePageContext().
Subclasses shall envelope this method.
This method should not be used by page or tag library authors.
release
in class PageContext
public void setAttribute(java.lang.String name, java.lang.Object attribute)
JspContext
null
,
this has the same effect as calling removeAttribute( name, PageContext.PAGE_SCOPE )
.setAttribute
in class JspContext
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.public void setAttribute(java.lang.String name, java.lang.Object attribute, int scope)
JspContext
null
, this has the same effect as calling removeAttribute( name, scope )
.setAttribute
in class JspContext
name
- the name of the attribute to setattribute
- 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/objectpublic java.lang.Object getAttribute(java.lang.String name)
JspContext
getAttribute
in class JspContext
name
- the name of the attribute to getpublic java.lang.Object getAttribute(java.lang.String name, int scope)
JspContext
getAttribute
in class JspContext
name
- the name of the attribute to setscope
- the scope with which to associate the name/objectpublic java.lang.Object findAttribute(java.lang.String name)
JspContext
findAttribute
in class JspContext
name
- the name of the attribute to search forpublic void removeAttribute(java.lang.String name)
JspContext
removeAttribute
in class JspContext
name
- The name of the object to remove.public void removeAttribute(java.lang.String name, int scope)
JspContext
removeAttribute
in class JspContext
name
- The name of the object to remove.scope
- The scope where to look.public int getAttributesScope(java.lang.String name)
JspContext
getAttributesScope
in class JspContext
name
- the name of the attribute to return the scope forpublic java.util.Enumeration getAttributeNamesInScope(int scope)
JspContext
getAttributeNamesInScope
in class JspContext
scope
- the scope to enumerate all the attributes forpublic JspWriter getOut()
JspContext
getOut
in class JspContext
public HttpSession getSession()
PageContext
getSession
in class PageContext
public java.lang.Object getPage()
PageContext
getPage
in class PageContext
public ServletRequest getRequest()
PageContext
getRequest
in class PageContext
public ServletResponse getResponse()
PageContext
getResponse
in class PageContext
public java.lang.Exception getException()
PageContext
getException
in class PageContext
public ServletConfig getServletConfig()
PageContext
getServletConfig
in class PageContext
public ServletContext getServletContext()
PageContext
getServletContext
in class PageContext
public void forward(java.lang.String path)
PageContext
This 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 ServletContext
for 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 Thread
executing within a
_jspService(...)
method of a JSP.
Once this method has been called successfully, it is illegal for the calling Thread
to attempt to
modify the
ServletResponse
object. Any such attempt to do so, shall result in undefined behavior. Typically, callers
immediately return from _jspService(...)
after calling this method.
forward
in class PageContext
path
- specifies the relative URL path to the target resource as described abovepublic void include(java.lang.String path)
PageContext
Causes 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 ServletContext
for 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 Thread
executing within a
_jspService(...)
method of a JSP.
include
in class PageContext
path
- specifies the relative URL path to the target resource to be includedpublic void handlePageException(java.lang.Exception exc)
PageContext
This 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 compatiblity reasons. Newly generated code should use PageContext.handlePageException(Throwable).
handlePageException
in class PageContext
exc
- the exception to be handledPageContext.handlePageException(Throwable)
public void handlePageException(java.lang.Throwable exc)
PageContext
This 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.
handlePageException
in class PageContext
exc
- the throwable to be handledPageContext.handlePageException(Exception)
public void include(java.lang.String relativeUrlPath, boolean flush)
PageContext
Causes 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 ServletContext
for 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 Thread
executing within a
_jspService(...)
method of a JSP.
include
in class PageContext
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.public ExpressionEvaluator getExpressionEvaluator()
JspContext
getExpressionEvaluator
in class JspContext
public VariableResolver getVariableResolver()
JspContext
getVariableResolver
in class JspContext
public javax.el.ELContext getELContext()
JspContext
ELContext
associated with this JspContext
.
The ELContext
is created lazily and is reused if it already exists. There is a new
ELContext
for each JspContext
.
The ELContext
must contain the ELResolver
described in the JSP specification (and in
the javadocs for JspApplicationContext.addELResolver(ELResolver)
).
getELContext
in class JspContext
ELContext
associated with this JspContext
.