JspFactory (Java EE 5 SDK)

javax.servlet.jsp Class JspFactory

java.lang.Object
  javax.servlet.jsp.JspFactory

public abstract class JspFactory

extends Object

The JspFactory is an abstract class that defines a number of factory methods available to a JSP page at runtime for the purposes of creating instances of various interfaces and classes used to support the JSP implementation.

A conformant JSP Engine implementation will, during it's initialization instantiate an implementation dependent subclass of this class, and make it globally available for use by JSP implementation classes by registering the instance created with this class via the static setDefaultFactory() method.

The only implementation-dependent classes that can be created from the factory are: PageContext, JspEngineInfo, and JspApplicationContext.

With the exception of JspApplicationContext, JspFactory objects should not be used by JSP application developers.

JspFactory

public JspFactory()

Sole constructor. (For invocation by subclass constructors, typically implicit.)

setDefaultFactory

public static void setDefaultFactory(JspFactory deflt)

set the default factory for this implementation. It is illegal for any principal other than the JSP Engine runtime to call this method.

参数:

deflt - The default factory implementation

getDefaultFactory

public static JspFactory getDefaultFactory()

Returns the default factory for this implementation.

返回:

the default factory for this implementation

getPageContext

public abstract PageContext getPageContext(Servlet servlet,
                                           ServletRequest request,
                                           ServletResponse response,
                                           String errorPageURL,
                                           boolean needsSession,
                                           int buffer,
                                           boolean autoflush)

obtains an instance of an implementation dependent javax.servlet.jsp.PageContext abstract class for the calling Servlet and currently pending request and response.

This method is typically called early in the processing of the _jspService() method of a JSP implementation class in order to obtain a PageContext object for the request being processed.

Invoking this method shall result in the PageContext.initialize() method being invoked. The PageContext returned is properly initialized.

All PageContext objects obtained via this method shall be released by invoking releasePageContext().

参数:

servlet - the requesting servlet

request - the current request pending on the servlet

response - the current response pending on the servlet

errorPageURL - the URL of the error page for the requesting JSP, or null

needsSession - true if the JSP participates in a session

buffer - size of buffer in bytes, PageContext.NO_BUFFER if no buffer, PageContext.DEFAULT_BUFFER if implementation default.

autoflush - should the buffer autoflush to the output stream on buffer overflow, or throw an IOException?

返回:

the page context

另请参见:

PageContext

releasePageContext

public abstract void releasePageContext(PageContext pc)

called to release a previously allocated PageContext object. Results in PageContext.release() being invoked. This method should be invoked prior to returning from the _jspService() method of a JSP implementation class.

参数:

pc - A PageContext previously obtained by getPageContext()

getEngineInfo

public abstract JspEngineInfo getEngineInfo()

called to get implementation-specific information on the current JSP engine.

返回:

a JspEngineInfo object describing the current JSP engine

getJspApplicationContext

public abstract JspApplicationContext getJspApplicationContext(ServletContext context)

Obtains the JspApplicationContext instance associated with the web application for the given ServletContext.

参数:

context - The ServletContext for the web application the desired JspApplicationContext is associated with.

返回:

The JspApplicationContext associated with the web application.

从以下版本开始:

2.1

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