JspContextWrapper (Apache Tomcat 6.0.53 API Documentation)

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org.apache.jasper.runtime
Class JspContextWrapper

java.lang.Object
  javax.servlet.jsp.JspContext
      javax.servlet.jsp.PageContext
          org.apache.jasper.runtime.JspContextWrapper

All Implemented Interfaces:: javax.servlet.jsp.el.VariableResolver

public class JspContextWrapper
extends javax.servlet.jsp.PageContext
implements javax.servlet.jsp.el.VariableResolver
extends javax.servlet.jsp.PageContext
implements javax.servlet.jsp.el.VariableResolver

Implementation of a JSP Context Wrapper. The JSP Context Wrapper is a JspContext created and maintained by a tag handler implementation. It wraps the Invoking JSP Context, that is, the JspContext instance passed to the tag handler by the invoking page via setJspContext().

Author:: Kin-man Chung, Jan Luehe, Jacob Hookom

Field Summary

Fields inherited from class javax.servlet.jsp.PageContext
`APPLICATION, APPLICATION_SCOPE, CONFIG, EXCEPTION, OUT, PAGE, PAGE_SCOPE, PAGECONTEXT, REQUEST, REQUEST_SCOPE, RESPONSE, SESSION, SESSION_SCOPE`

Constructor Summary
`JspContextWrapper(javax.servlet.jsp.JspContext jspContext, java.util.ArrayList nestedVars, java.util.ArrayList atBeginVars, java.util.ArrayList atEndVars, java.util.Map aliases)`

Method Summary
`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 relativeUrlPath)` 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<java.lang.String>`	`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()`
`java.lang.Exception`	`getException()` The current value of the exception object (an Exception).
`javax.servlet.jsp.el.ExpressionEvaluator`	`getExpressionEvaluator()` Provides programmatic access to the ExpressionEvaluator.
`javax.servlet.jsp.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).
`javax.servlet.ServletRequest`	`getRequest()` The current value of the request object (a ServletRequest).
`javax.servlet.ServletResponse`	`getResponse()` The current value of the response object (a ServletResponse).
`javax.servlet.ServletConfig`	`getServletConfig()` The ServletConfig instance.
`javax.servlet.ServletContext`	`getServletContext()` The ServletContext instance.
`javax.servlet.http.HttpSession`	`getSession()` The current value of the session object (an HttpSession).
`javax.servlet.jsp.el.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 ex)` 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 t)` 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 relativeUrlPath)` 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(javax.servlet.Servlet servlet, javax.servlet.ServletRequest request, javax.servlet.ServletResponse response, java.lang.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.
`javax.servlet.jsp.JspWriter`	`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.
`javax.servlet.jsp.tagext.BodyContent`	`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.
`javax.servlet.jsp.JspWriter`	`pushBody(java.io.Writer writer)` Return a new JspWriter object that sends output to the provided Writer.
`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.
`java.lang.Object`	`resolveVariable(java.lang.String pName)` VariableResolver interface
`void`	`setAttribute(java.lang.String name, java.lang.Object value)` Register the name and value specified with page scope semantics.
`void`	`setAttribute(java.lang.String name, java.lang.Object value, int scope)` Register the name and value specified with appropriate scope semantics.
`void`	`syncBeforeInvoke()` Synchronize variables before fragment invokation
`void`	`syncBeginTagFile()` Synchronize variables at begin of tag file
`void`	`syncEndTagFile()` Synchronize variables at end of tag file

Methods inherited from class javax.servlet.jsp.PageContext
`getErrorData`

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Constructor Detail

JspContextWrapper

public JspContextWrapper(javax.servlet.jsp.JspContext jspContext,
                         java.util.ArrayList nestedVars,
                         java.util.ArrayList atBeginVars,
                         java.util.ArrayList atEndVars,
                         java.util.Map aliases)

Method Detail

initialize

public void initialize(javax.servlet.Servlet servlet,
                       javax.servlet.ServletRequest request,
                       javax.servlet.ServletResponse response,
                       java.lang.String errorPageURL,
                       boolean needsSession,
                       int bufferSize,
                       boolean autoFlush)
                throws java.io.IOException,
                       java.lang.IllegalStateException,
                       java.lang.IllegalArgumentException

Description copied from class: javax.servlet.jsp.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.

Specified by:: initialize in class javax.servlet.jsp.PageContext

Parameters:: servlet - The Servlet that is associated with this PageContext; request - The currently pending request for this Servlet; response - The currently pending response for this Servlet; errorPageURL - The value of the errorpage attribute from the page directive or null; needsSession - The value of the session attribute from the page directive; bufferSize - The value of the buffer attribute from the page directive; autoFlush - The value of the autoflush attribute from the page directive
Throws:: java.io.IOException - during creation of JspWriter; java.lang.IllegalStateException - if out not correctly initialized; java.lang.IllegalArgumentException - If one of the given parameters is invalid

getAttribute

public java.lang.Object getAttribute(java.lang.String name)

Description copied from class: javax.servlet.jsp.JspContext

Returns the object associated with the name in the page scope or null if not found.

Specified by:: getAttribute in class javax.servlet.jsp.JspContext

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

public java.lang.Object getAttribute(java.lang.String name,
                                     int scope)

Description copied from class: javax.servlet.jsp.JspContext

Return the object associated with the name in the specified scope or null if not found.

Specified by:: getAttribute in class javax.servlet.jsp.JspContext

Parameters:: name - the name of the attribute to set; scope - 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

public void setAttribute(java.lang.String name,
                         java.lang.Object value)

Description copied from class: javax.servlet.jsp.JspContext

Register the name and value specified with page scope semantics. If the value passed in is null, this has the same effect as calling removeAttribute( name, PageContext.PAGE_SCOPE ).

Specified by:: setAttribute in class javax.servlet.jsp.JspContext

Parameters:: name - the name of the attribute to set; value - the value to associate with the name, or null if the attribute is to be removed from the page scope.

setAttribute

public void setAttribute(java.lang.String name,
                         java.lang.Object value,
                         int scope)

Description copied from class: javax.servlet.jsp.JspContext

Register the name and value specified with appropriate scope semantics. If the value passed in is null, this has the same effect as calling removeAttribute( name, scope ).

Specified by:: setAttribute in class javax.servlet.jsp.JspContext

Parameters:: name - the name of the attribute to set; value - 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

findAttribute

public java.lang.Object findAttribute(java.lang.String name)

Description copied from class: javax.servlet.jsp.JspContext

Searches 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:: findAttribute in class javax.servlet.jsp.JspContext

Parameters:: name - the name of the attribute to search for
Returns:: the value associated or null

removeAttribute

public void removeAttribute(java.lang.String name)

Description copied from class: javax.servlet.jsp.JspContext

Remove the object reference associated with the given name from all scopes. Does nothing if there is no such object.

Specified by:: removeAttribute in class javax.servlet.jsp.JspContext

Parameters:: name - The name of the object to remove.

removeAttribute

public void removeAttribute(java.lang.String name,
                            int scope)

Description copied from class: javax.servlet.jsp.JspContext

Remove the object reference associated with the specified name in the given scope. Does nothing if there is no such object.

Specified by:: removeAttribute in class javax.servlet.jsp.JspContext

Parameters:: name - The name of the object to remove.; scope - The scope where to look.

getAttributesScope

public int getAttributesScope(java.lang.String name)

Description copied from class: javax.servlet.jsp.JspContext

Get the scope where a given attribute is defined.

Specified by:: getAttributesScope in class javax.servlet.jsp.JspContext

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

getAttributeNamesInScope

public java.util.Enumeration<java.lang.String> getAttributeNamesInScope(int scope)

Description copied from class: javax.servlet.jsp.JspContext

Enumerate all the attributes in a given scope.

Specified by:: getAttributeNamesInScope in class javax.servlet.jsp.JspContext

Parameters:: scope - the scope to enumerate all the attributes for
Returns:: an enumeration of names (java.lang.String) of all the attributes the specified scope

release

public void release()

Description copied from class: javax.servlet.jsp.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.

Specified by:: release in class javax.servlet.jsp.PageContext

getOut

public javax.servlet.jsp.JspWriter getOut()

Description copied from class: javax.servlet.jsp.JspContext

The current value of the out object (a JspWriter).

Specified by:: getOut in class javax.servlet.jsp.JspContext

Returns:: the current JspWriter stream being used for client response

getSession

public javax.servlet.http.HttpSession getSession()

Description copied from class: javax.servlet.jsp.PageContext

The current value of the session object (an HttpSession).

Specified by:: getSession in class javax.servlet.jsp.PageContext

Returns:: the HttpSession for this PageContext or null

getPage

public java.lang.Object getPage()

Description copied from class: javax.servlet.jsp.PageContext

The current value of the page object (In a Servlet environment, this is an instance of javax.servlet.Servlet).

Specified by:: getPage in class javax.servlet.jsp.PageContext

Returns:: the Page implementation class instance associated with this PageContext

getRequest

public javax.servlet.ServletRequest getRequest()

Description copied from class: javax.servlet.jsp.PageContext

The current value of the request object (a ServletRequest).

Specified by:: getRequest in class javax.servlet.jsp.PageContext

Returns:: The ServletRequest for this PageContext

getResponse

public javax.servlet.ServletResponse getResponse()

Description copied from class: javax.servlet.jsp.PageContext

The current value of the response object (a ServletResponse).

Specified by:: getResponse in class javax.servlet.jsp.PageContext

Returns:: the ServletResponse for this PageContext

getException

public java.lang.Exception getException()

Description copied from class: javax.servlet.jsp.PageContext

The current value of the exception object (an Exception).

Specified by:: getException in class javax.servlet.jsp.PageContext

Returns:: any exception passed to this as an errorpage

getServletConfig

public javax.servlet.ServletConfig getServletConfig()

Description copied from class: javax.servlet.jsp.PageContext

The ServletConfig instance.

Specified by:: getServletConfig in class javax.servlet.jsp.PageContext

Returns:: the ServletConfig for this PageContext

getServletContext

public javax.servlet.ServletContext getServletContext()

Description copied from class: javax.servlet.jsp.PageContext

The ServletContext instance.

Specified by:: getServletContext in class javax.servlet.jsp.PageContext

Returns:: the ServletContext for this PageContext

forward

public void forward(java.lang.String relativeUrlPath)
             throws javax.servlet.ServletException,
                    java.io.IOException

Description copied from class: javax.servlet.jsp.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.

Specified by:: forward in class javax.servlet.jsp.PageContext

Parameters:: relativeUrlPath - specifies the relative URL path to the target resource as described above
Throws:: javax.servlet.ServletException - if the page that was forwarded to throws a ServletException; java.io.IOException - if an I/O error occurred while forwarding

include

public void include(java.lang.String relativeUrlPath)
             throws javax.servlet.ServletException,
                    java.io.IOException

Description copied from class: javax.servlet.jsp.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.

It is only valid to call this method from a Thread executing within a _jspService(...) method of a JSP.

Specified by:: include in class javax.servlet.jsp.PageContext

Parameters:: relativeUrlPath - specifies the relative URL path to the target resource to be included
Throws:: javax.servlet.ServletException - if the page that was forwarded to throws a ServletException; java.io.IOException - if an I/O error occurred while forwarding

include

public void include(java.lang.String relativeUrlPath,
                    boolean flush)
             throws javax.servlet.ServletException,
                    java.io.IOException

Description copied from class: javax.servlet.jsp.PageContext

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.

It is only valid to call this method from a Thread executing within a _jspService(...) method of a JSP.

Specified by:: include in class javax.servlet.jsp.PageContext

Parameters:: relativeUrlPath - specifies the relative URL path to the target resource to be included; flush - True if the JspWriter is to be flushed before the include, or false if not.
Throws:: javax.servlet.ServletException - if the page that was forwarded to throws a ServletException; java.io.IOException - if an I/O error occurred while forwarding

getVariableResolver

public javax.servlet.jsp.el.VariableResolver getVariableResolver()

Description copied from class: javax.servlet.jsp.JspContext

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.

Specified by:: getVariableResolver in class javax.servlet.jsp.JspContext

Returns:: A valid instance of a VariableResolver.

pushBody

public javax.servlet.jsp.tagext.BodyContent pushBody()

Description copied from class: javax.servlet.jsp.PageContext

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.

Overrides:: pushBody in class javax.servlet.jsp.PageContext

Returns:: the new BodyContent

pushBody

public javax.servlet.jsp.JspWriter pushBody(java.io.Writer writer)

Description copied from class: javax.servlet.jsp.JspContext

Return 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:: pushBody in class javax.servlet.jsp.JspContext

Parameters:: writer - The Writer for the returned JspWriter to send output to.
Returns:: a new JspWriter that writes to the given Writer.

popBody

public javax.servlet.jsp.JspWriter popBody()

Description copied from class: javax.servlet.jsp.JspContext

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.

Overrides:: popBody in class javax.servlet.jsp.JspContext

Returns:: the saved JspWriter.

getExpressionEvaluator

public javax.servlet.jsp.el.ExpressionEvaluator getExpressionEvaluator()

Description copied from class: javax.servlet.jsp.JspContext

Provides programmatic access to the ExpressionEvaluator. The JSP Container must return a valid instance of an ExpressionEvaluator that can parse EL expressions.

Specified by:: getExpressionEvaluator in class javax.servlet.jsp.JspContext

Returns:: A valid instance of an ExpressionEvaluator.

handlePageException

public void handlePageException(java.lang.Exception ex)
                         throws java.io.IOException,
                                javax.servlet.ServletException

Description copied from class: javax.servlet.jsp.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).

Specified by:: handlePageException in class javax.servlet.jsp.PageContext

Parameters:: ex - the exception to be handled
Throws:: java.io.IOException - if an I/O error occurred while invoking the error page; javax.servlet.ServletException - if an error occurs while invoking the error page
See Also:: PageContext.handlePageException(Throwable)

handlePageException

public void handlePageException(java.lang.Throwable t)
                         throws java.io.IOException,
                                javax.servlet.ServletException

Description copied from class: javax.servlet.jsp.PageContext

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.

Specified by:: handlePageException in class javax.servlet.jsp.PageContext

Parameters:: t - the throwable to be handled
Throws:: java.io.IOException - if an I/O error occurred while invoking the error page; javax.servlet.ServletException - if an error occurs while invoking the error page
See Also:: PageContext.handlePageException(Exception)

resolveVariable

public java.lang.Object resolveVariable(java.lang.String pName)
                                 throws javax.servlet.jsp.el.ELException

VariableResolver interface

Specified by:: resolveVariable in interface javax.servlet.jsp.el.VariableResolver

Parameters:: pName - the name of the variable to resolve
Returns:: the result of the variable resolution
Throws:: javax.servlet.jsp.el.ELException - if a failure occurred while trying to resolve the given variable

syncBeginTagFile

public void syncBeginTagFile()

Synchronize variables at begin of tag file

syncBeforeInvoke

public void syncBeforeInvoke()

Synchronize variables before fragment invokation

syncEndTagFile

public void syncEndTagFile()

Synchronize variables at end of tag file

getELContext

public javax.el.ELContext getELContext()

Specified by:: getELContext in class javax.servlet.jsp.JspContext

Overview

Package

Class

Tree

Deprecated

Index

Help

Apache Tomcat 6.0.53

PREV CLASS NEXT CLASS

FRAMES NO FRAMES

SUMMARY: NESTED | FIELD | CONSTR | METHOD

DETAIL: FIELD | CONSTR | METHOD

org.apache.jasper.runtime Class JspContextWrapper

JspContextWrapper

initialize

getAttribute

getAttribute

setAttribute

setAttribute

findAttribute

removeAttribute

removeAttribute

getAttributesScope

getAttributeNamesInScope

release

getOut

getSession

getPage

getRequest

getResponse

getException

getServletConfig

getServletContext

forward

include

include

getVariableResolver

pushBody

pushBody

popBody

getExpressionEvaluator

handlePageException

handlePageException

resolveVariable

syncBeginTagFile

syncBeforeInvoke

syncEndTagFile

getELContext

org.apache.jasper.runtime
Class JspContextWrapper