📄 jspcontext.html
字号:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><!--NewPage--><HTML><HEAD><!-- Generated by javadoc (build 1.4.2) on Thu Oct 16 19:57:34 EDT 2003 --><TITLE>JspContext (JavaServer Pages API Documentation)</TITLE><META NAME="keywords" CONTENT="javax.servlet.jsp.JspContext class"><LINK REL ="stylesheet" TYPE="text/css" HREF="../../../stylesheet.css" TITLE="Style"><SCRIPT type="text/javascript">function windowTitle(){ parent.document.title="JspContext (JavaServer Pages API Documentation)";}</SCRIPT></HEAD><BODY BGCOLOR="white" onload="windowTitle();"><!-- ========= START OF TOP NAVBAR ======= --><A NAME="navbar_top"><!-- --></A><A HREF="#skip-navbar_top" title="Skip navigation links"></A><TABLE BORDER="0" WIDTH="100%" CELLPADDING="1" CELLSPACING="0" SUMMARY=""><TR><TD COLSPAN=3 BGCOLOR="#EEEEFF" CLASS="NavBarCell1"><A NAME="navbar_top_firstrow"><!-- --></A><TABLE BORDER="0" CELLPADDING="0" CELLSPACING="3" SUMMARY=""> <TR ALIGN="center" VALIGN="top"> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../../overview-summary.html"><FONT CLASS="NavBarFont1"><B>Overview</B></FONT></A> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="package-summary.html"><FONT CLASS="NavBarFont1"><B>Package</B></FONT></A> </TD> <TD BGCOLOR="#FFFFFF" CLASS="NavBarCell1Rev"> <FONT CLASS="NavBarFont1Rev"><B>Class</B></FONT> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="class-use/JspContext.html"><FONT CLASS="NavBarFont1"><B>Use</B></FONT></A> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="package-tree.html"><FONT CLASS="NavBarFont1"><B>Tree</B></FONT></A> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../../deprecated-list.html"><FONT CLASS="NavBarFont1"><B>Deprecated</B></FONT></A> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../../index-all.html"><FONT CLASS="NavBarFont1"><B>Index</B></FONT></A> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../../help-doc.html"><FONT CLASS="NavBarFont1"><B>Help</B></FONT></A> </TD> </TR></TABLE></TD><TD ALIGN="right" VALIGN="top" ROWSPAN=3><EM></EM></TD></TR><TR><TD BGCOLOR="white" CLASS="NavBarCell2"><FONT SIZE="-2"> <A HREF="../../../javax/servlet/jsp/ErrorData.html" title="class in javax.servlet.jsp"><B>PREV CLASS</B></A> <A HREF="../../../javax/servlet/jsp/JspEngineInfo.html" title="class in javax.servlet.jsp"><B>NEXT CLASS</B></A></FONT></TD><TD BGCOLOR="white" CLASS="NavBarCell2"><FONT SIZE="-2"> <A HREF="../../../index.html" target="_top"><B>FRAMES</B></A> <A HREF="JspContext.html" target="_top"><B>NO FRAMES</B></A> <SCRIPT type="text/javascript"> <!-- if(window==top) { document.writeln('<A HREF="../../../allclasses-noframe.html"><B>All Classes</B></A>'); } //--></SCRIPT><NOSCRIPT> <A HREF="../../../allclasses-noframe.html"><B>All Classes</B></A></NOSCRIPT></FONT></TD></TR><TR><TD VALIGN="top" CLASS="NavBarCell3"><FONT SIZE="-2"> SUMMARY: NESTED | FIELD | <A HREF="#constructor_summary">CONSTR</A> | <A HREF="#method_summary">METHOD</A></FONT></TD><TD VALIGN="top" CLASS="NavBarCell3"><FONT SIZE="-2">DETAIL: FIELD | <A HREF="#constructor_detail">CONSTR</A> | <A HREF="#method_detail">METHOD</A></FONT></TD></TR></TABLE><A NAME="skip-navbar_top"></A><!-- ========= END OF TOP NAVBAR ========= --><HR><!-- ======== START OF CLASS DATA ======== --><H2><FONT SIZE="-1">javax.servlet.jsp</FONT><BR>Class JspContext</H2><PRE>java.lang.Object <IMG SRC="../../../resources/inherit.gif" ALT="extended by"><B>javax.servlet.jsp.JspContext</B></PRE><DL><DT><B>Direct Known Subclasses:</B> <DD><A HREF="../../../javax/servlet/jsp/PageContext.html" title="class in javax.servlet.jsp">PageContext</A></DD></DL><HR><DL><DT>public abstract class <B>JspContext</B><DT>extends java.lang.Object</DL><P><p> <code>JspContext</code> serves as the base class for the PageContext class and abstracts all information that is not specific to servlets. This allows for Simple Tag Extensions to be used outside of the context of a request/response Servlet. <p> The JspContext provides a number of facilities to the page/component author and page implementor, including: <ul> <li>a single API to manage the various scoped namespaces <li>a mechanism to obtain the JspWriter for output <li>a mechanism to expose page directive attributes to the scripting environment </ul> <p><B>Methods Intended for Container Generated Code</B> <p> The following methods enable the <B>management of nested</B> JspWriter streams to implement Tag Extensions: <code>pushBody()</code> and <code>popBody()</code> <p><B>Methods Intended for JSP authors</B> <p> Some methods provide <B>uniform access</B> to the diverse objects representing scopes. The implementation must use the underlying machinery corresponding to that scope, so information can be passed back and forth between the underlying environment (e.g. Servlets) and JSP pages. The methods are: <code>setAttribute()</code>, <code>getAttribute()</code>, <code>findAttribute()</code>, <code>removeAttribute()</code>, <code>getAttributesScope()</code> and <code>getAttributeNamesInScope()</code>. <p> The following methods provide <B>convenient access</B> to implicit objects: <code>getOut()</code> <p> The following methods provide <B>programmatic access</b> to the Expression Language evaluator: <code>getExpressionEvaluator()</code>, <code>getVariableResolver()</code><P><P><DL><DT><B>Since:</B></DT> <DD>2.0</DD></DL><HR><P><!-- ======== NESTED CLASS SUMMARY ======== --><!-- =========== FIELD SUMMARY =========== --><!-- ======== CONSTRUCTOR SUMMARY ======== --><A NAME="constructor_summary"><!-- --></A><TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY=""><TR BGCOLOR="#CCCCFF" CLASS="TableHeadingColor"><TD COLSPAN=2><FONT SIZE="+2"><B>Constructor Summary</B></FONT></TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD><CODE><B><A HREF="../../../javax/servlet/jsp/JspContext.html#JspContext()">JspContext</A></B>()</CODE><BR> Sole constructor.</TD></TR></TABLE> <!-- ========== METHOD SUMMARY =========== --><A NAME="method_summary"><!-- --></A><TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY=""><TR BGCOLOR="#CCCCFF" CLASS="TableHeadingColor"><TD COLSPAN=2><FONT SIZE="+2"><B>Method Summary</B></FONT></TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"><CODE>abstract java.lang.Object</CODE></FONT></TD><TD><CODE><B><A HREF="../../../javax/servlet/jsp/JspContext.html#findAttribute(java.lang.String)">findAttribute</A></B>(java.lang.String name)</CODE><BR> Searches for the named attribute in page, request, session (if valid), and application scope(s) in order and returns the value associated or null.</TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"><CODE>abstract java.lang.Object</CODE></FONT></TD><TD><CODE><B><A HREF="../../../javax/servlet/jsp/JspContext.html#getAttribute(java.lang.String)">getAttribute</A></B>(java.lang.String name)</CODE><BR> Returns the object associated with the name in the page scope or null if not found.</TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"><CODE>abstract java.lang.Object</CODE></FONT></TD><TD><CODE><B><A HREF="../../../javax/servlet/jsp/JspContext.html#getAttribute(java.lang.String, int)">getAttribute</A></B>(java.lang.String name, int scope)</CODE><BR> Return the object associated with the name in the specified scope or null if not found.</TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"><CODE>abstract java.util.Enumeration</CODE></FONT></TD><TD><CODE><B><A HREF="../../../javax/servlet/jsp/JspContext.html#getAttributeNamesInScope(int)">getAttributeNamesInScope</A></B>(int scope)</CODE><BR> Enumerate all the attributes in a given scope.</TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"><CODE>abstract int</CODE></FONT></TD><TD><CODE><B><A HREF="../../../javax/servlet/jsp/JspContext.html#getAttributesScope(java.lang.String)">getAttributesScope</A></B>(java.lang.String name)</CODE><BR> Get the scope where a given attribute is defined.</TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"><CODE>abstract <A HREF="../../../javax/servlet/jsp/el/ExpressionEvaluator.html" title="class in javax.servlet.jsp.el">ExpressionEvaluator</A></CODE></FONT></TD><TD><CODE><B><A HREF="../../../javax/servlet/jsp/JspContext.html#getExpressionEvaluator()">getExpressionEvaluator</A></B>()</CODE><BR> Provides programmatic access to the ExpressionEvaluator.</TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"><CODE>abstract <A HREF="../../../javax/servlet/jsp/JspWriter.html" title="class in javax.servlet.jsp">JspWriter</A></CODE></FONT></TD><TD><CODE><B><A HREF="../../../javax/servlet/jsp/JspContext.html#getOut()">getOut</A></B>()</CODE><BR> The current value of the out object (a JspWriter).</TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"><CODE>abstract <A HREF="../../../javax/servlet/jsp/el/VariableResolver.html" title="interface in javax.servlet.jsp.el">VariableResolver</A></CODE></FONT></TD><TD><CODE><B><A HREF="../../../javax/servlet/jsp/JspContext.html#getVariableResolver()">getVariableResolver</A></B>()</CODE><BR> 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.</TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"><CODE> <A HREF="../../../javax/servlet/jsp/JspWriter.html" title="class in javax.servlet.jsp">JspWriter</A></CODE></FONT></TD><TD><CODE><B><A HREF="../../../javax/servlet/jsp/JspContext.html#popBody()">popBody</A></B>()</CODE><BR> 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.</TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"><CODE> <A HREF="../../../javax/servlet/jsp/JspWriter.html" title="class in javax.servlet.jsp">JspWriter</A></CODE></FONT></TD><TD><CODE><B><A HREF="../../../javax/servlet/jsp/JspContext.html#pushBody(java.io.Writer)">pushBody</A></B>(java.io.Writer writer)</CODE><BR> Return a new JspWriter object that sends output to the provided Writer.</TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"><CODE>abstract void</CODE></FONT></TD><TD><CODE><B><A HREF="../../../javax/servlet/jsp/JspContext.html#removeAttribute(java.lang.String)">removeAttribute</A></B>(java.lang.String name)</CODE><BR> Remove the object reference associated with the given name from all scopes.</TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"><CODE>abstract void</CODE></FONT></TD><TD><CODE><B><A HREF="../../../javax/servlet/jsp/JspContext.html#removeAttribute(java.lang.String, int)">removeAttribute</A></B>(java.lang.String name, int scope)</CODE><BR> Remove the object reference associated with the specified name in the given scope.</TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"><CODE>abstract void</CODE></FONT></TD><TD><CODE><B><A HREF="../../../javax/servlet/jsp/JspContext.html#setAttribute(java.lang.String, java.lang.Object)">setAttribute</A></B>(java.lang.String name, java.lang.Object value)</CODE><BR> Register the name and value specified with page scope semantics.</TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"><CODE>abstract void</CODE></FONT></TD><TD><CODE><B><A HREF="../../../javax/servlet/jsp/JspContext.html#setAttribute(java.lang.String, java.lang.Object, int)">setAttribute</A></B>(java.lang.String name, java.lang.Object value, int scope)</CODE><BR> Register the name and value specified with appropriate scope semantics.</TD></TR></TABLE> <A NAME="methods_inherited_from_class_java.lang.Object"><!-- --></A><TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY=""><TR BGCOLOR="#EEEEFF" CLASS="TableSubHeadingColor"><TD><B>Methods inherited from class java.lang.Object</B></TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD><CODE>clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait</CODE></TD></TR></TABLE> <P><!-- ============ FIELD DETAIL =========== --><!-- ========= CONSTRUCTOR DETAIL ======== --><A NAME="constructor_detail"><!-- --></A><TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY=""><TR BGCOLOR="#CCCCFF" CLASS="TableHeadingColor"><TD COLSPAN=1><FONT SIZE="+2"><B>Constructor Detail</B></FONT></TD></TR></TABLE><A NAME="JspContext()"><!-- --></A><H3>JspContext</H3><PRE>public <B>JspContext</B>()</PRE><DL><DD>Sole constructor. (For invocation by subclass constructors, typically implicit.)<P></DL><!-- ============ METHOD DETAIL ========== -->⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -