servletcontext.html

j2ee帮助文档软件设计/软件工程 文件格式

<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE>&nbsp;<A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/String.html" title="class or interface in java.lang">String</A></CODE></FONT></TD>
<TD><CODE><B><A HREF="../../javax/servlet/ServletContext.html#getServerInfo()">getServerInfo</A></B>()</CODE>

<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Returns the name and version of the servlet container on which
 the servlet is running.</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE>&nbsp;<A HREF="../../javax/servlet/Servlet.html" title="interface in javax.servlet">Servlet</A></CODE></FONT></TD>
<TD><CODE><B><A HREF="../../javax/servlet/ServletContext.html#getServlet(java.lang.String)">getServlet</A></B>(<A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/String.html" title="class or interface in java.lang">String</A>&nbsp;name)</CODE>

<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>Deprecated.</B>&nbsp;<I>As of Java Servlet API 2.1, with no direct replacement.

 <p>This method was originally defined to retrieve a servlet
 from a <code>ServletContext</code>. In this version, this method 
 always returns <code>null</code> and remains only to preserve 
 binary compatibility. This method will be permanently removed 
 in a future version of the Java Servlet API.

 <p>In lieu of this method, servlets can share information using the 
 <code>ServletContext</code> class and can perform shared business logic
 by invoking methods on common non-servlet classes.</I></TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE>&nbsp;<A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/String.html" title="class or interface in java.lang">String</A></CODE></FONT></TD>
<TD><CODE><B><A HREF="../../javax/servlet/ServletContext.html#getServletContextName()">getServletContextName</A></B>()</CODE>

<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Returns the name of this web application corresponding to this ServletContext as specified in the deployment
 descriptor for this web application by the display-name element.</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE>&nbsp;<A HREF="http://java.sun.com/j2se/1.5/docs/api/java/util/Enumeration.html" title="class or interface in java.util">Enumeration</A></CODE></FONT></TD>
<TD><CODE><B><A HREF="../../javax/servlet/ServletContext.html#getServletNames()">getServletNames</A></B>()</CODE>

<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>Deprecated.</B>&nbsp;<I>As of Java Servlet API 2.1, with no replacement.

 <p>This method was originally defined to return an 
 <code>Enumeration</code>
 of all the servlet names known to this context. In this version,
 this method always returns an empty <code>Enumeration</code> and 
 remains only to preserve binary compatibility. This method will 
 be permanently removed in a future version of the Java Servlet API.</I></TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE>&nbsp;<A HREF="http://java.sun.com/j2se/1.5/docs/api/java/util/Enumeration.html" title="class or interface in java.util">Enumeration</A></CODE></FONT></TD>
<TD><CODE><B><A HREF="../../javax/servlet/ServletContext.html#getServlets()">getServlets</A></B>()</CODE>

<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>Deprecated.</B>&nbsp;<I>As of Java Servlet API 2.0, with no replacement.

 <p>This method was originally defined to return an <code>Enumeration</code>
 of all the servlets known to this servlet context. In this
 version, this method always returns an empty enumeration and
 remains only to preserve binary compatibility. This method
 will be permanently removed in a future version of the Java
 Servlet API.</I></TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE>&nbsp;void</CODE></FONT></TD>
<TD><CODE><B><A HREF="../../javax/servlet/ServletContext.html#log(java.lang.Exception, java.lang.String)">log</A></B>(<A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/Exception.html" title="class or interface in java.lang">Exception</A>&nbsp;exception,
    <A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/String.html" title="class or interface in java.lang">String</A>&nbsp;msg)</CODE>

<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>Deprecated.</B>&nbsp;<I>As of Java Servlet API 2.1, use
                        <A HREF="../../javax/servlet/ServletContext.html#log(java.lang.String, java.lang.Throwable)"><CODE>log(String message, Throwable throwable)</CODE></A> 
                        instead.

 <p>This method was originally defined to write an 
 exception's stack trace and an explanatory error message
 to the servlet log file.</I></TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE>&nbsp;void</CODE></FONT></TD>
<TD><CODE><B><A HREF="../../javax/servlet/ServletContext.html#log(java.lang.String)">log</A></B>(<A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/String.html" title="class or interface in java.lang">String</A>&nbsp;msg)</CODE>

<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Writes the specified message to a servlet log file, usually
 an event log.</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE>&nbsp;void</CODE></FONT></TD>
<TD><CODE><B><A HREF="../../javax/servlet/ServletContext.html#log(java.lang.String, java.lang.Throwable)">log</A></B>(<A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/String.html" title="class or interface in java.lang">String</A>&nbsp;message,
    <A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/Throwable.html" title="class or interface in java.lang">Throwable</A>&nbsp;throwable)</CODE>

<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Writes an explanatory message and a stack trace
 for a given <code>Throwable</code> exception
 to the servlet log file.</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE>&nbsp;void</CODE></FONT></TD>
<TD><CODE><B><A HREF="../../javax/servlet/ServletContext.html#removeAttribute(java.lang.String)">removeAttribute</A></B>(<A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/String.html" title="class or interface in java.lang">String</A>&nbsp;name)</CODE>

<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Removes the attribute with the given name from 
 the servlet context.</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE>&nbsp;void</CODE></FONT></TD>
<TD><CODE><B><A HREF="../../javax/servlet/ServletContext.html#setAttribute(java.lang.String, java.lang.Object)">setAttribute</A></B>(<A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/String.html" title="class or interface in java.lang">String</A>&nbsp;name,
             <A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/Object.html" title="class or interface in java.lang">Object</A>&nbsp;object)</CODE>

<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Binds an object to a given attribute name in this servlet context.</TD>
</TR>
</TABLE>
&nbsp;
<P>

<!-- ============ METHOD DETAIL ========== -->

<A NAME="method_detail"><!-- --></A>
<TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY="">
<TR BGCOLOR="#CCCCFF" CLASS="TableHeadingColor">
<TH ALIGN="left" COLSPAN="1"><FONT SIZE="+2">
<B>Method Detail</B></FONT></TH>
</TR>
</TABLE>

<A NAME="getContextPath()"><!-- --></A><H3>
getContextPath</H3>
<PRE>
<A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/String.html" title="class or interface in java.lang">String</A> <B>getContextPath</B>()</PRE>
<DL>
<DD>Returns the context path of the web application.

 <p>The context path is the portion of the request URI that is used
 to select the context of the request. The context path always comes
 first in a request URI. The path starts with a "/" character but does
 not end with a "/" character. For servlets in the default (root)
 context, this method returns "".

 <p>It is possible that a servlet container may match a context by
 more than one context path. In such cases the
 <A HREF="../../javax/servlet/http/HttpServletRequest.html#getContextPath()"><CODE>HttpServletRequest.getContextPath()</CODE></A>
 will return the actual context path used by the request and it may
 differ from the path returned by this method.
 The context path returned by this method should be considered as the
 prime or preferred context path of the application.
<P>
<DD><DL>

<DT><B>Returns:</B><DD>The context path of the web application, or "" for the
 default (root) context<DT><B>Since:</B></DT>
  <DD>Servlet 2.5</DD>
<DT><B>See Also:</B><DD><A HREF="../../javax/servlet/http/HttpServletRequest.html#getContextPath()"><CODE>HttpServletRequest.getContextPath()</CODE></A></DL>
</DD>
</DL>
<HR>

<A NAME="getContext(java.lang.String)"><!-- --></A><H3>
getContext</H3>
<PRE>
<A HREF="../../javax/servlet/ServletContext.html" title="interface in javax.servlet">ServletContext</A> <B>getContext</B>(<A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/String.html" title="class or interface in java.lang">String</A>&nbsp;uripath)</PRE>
<DL>
<DD>Returns a <code>ServletContext</code> object that 
 corresponds to a specified URL on the server.

 <p>This method allows servlets to gain
 access to the context for various parts of the server, and as
 needed obtain <A HREF="../../javax/servlet/RequestDispatcher.html" title="interface in javax.servlet"><CODE>RequestDispatcher</CODE></A> objects from the context.
 The given path must be begin with "/", is interpreted relative 
 to the server's document root and is matched against the context roots of
 other web applications hosted on this container.
 
 <p>In a security conscious environment, the servlet container may
 return <code>null</code> for a given URL.
<P>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>uripath</CODE> - a <code>String</code> specifying the context path of
                        another web application in the container.
<DT><B>Returns:</B><DD>the <code>ServletContext</code> object that
                        corresponds to the named URL, or null if either
                        none exists or the container wishes to restrict 
                        this access.<DT><B>See Also:</B><DD><A HREF="../../javax/servlet/RequestDispatcher.html" title="interface in javax.servlet"><CODE>RequestDispatcher</CODE></A></DL>
</DD>
</DL>
<HR>

<A NAME="getMajorVersion()"><!-- --></A><H3>
getMajorVersion</H3>
<PRE>
int <B>getMajorVersion</B>()</PRE>
<DL>
<DD>Returns the major version of the Java Servlet API that this
 servlet container supports. All implementations that comply
 with Version 2.5 must have this method
 return the integer 2.
<P>
<DD><DL>

<DT><B>Returns:</B><DD>2</DL>
</DD>
</DL>
<HR>

<A NAME="getMinorVersion()"><!-- --></A><H3>
getMinorVersion</H3>
<PRE>
int <B>getMinorVersion</B>()</PRE>
<DL>
<DD>Returns the minor version of the Servlet API that this
 servlet container supports. All implementations that comply
 with Version 2.5 must have this method
 return the integer 5.
<P>
<DD><DL>

<DT><B>Returns:</B><DD>5</DL>
</DD>
</DL>
<HR>

<A NAME="getMimeType(java.lang.String)"><!-- --></A><H3>
getMimeType</H3>
<PRE>
<A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/String.html" title="class or interface in java.lang">String</A> <B>getMimeType</B>(<A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/String.html" title="class or interface in java.lang">String</A>&nbsp;file)</PRE>
<DL>
<DD>Returns the MIME type of the specified file, or <code>null</code> if 
 the MIME type is not known. The MIME type is determined
 by the configuration of the servlet container, and may be specified
 in a web application deployment descriptor. Common MIME
 types are <code>"text/html"</code> and <code>"image/gif"</code>.
<P>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>file</CODE> - a <code>String</code> specifying the name
                        of a file
<DT><B>Returns:</B><DD>a <code>String</code> specifying the file's MIME type</DL>
</DD>
</DL>
<HR>

<A NAME="getResourcePaths(java.lang.String)"><!-- --></A><H3>
getResourcePaths</H3>
<PRE>
<A HREF="http://java.sun.com/j2se/1.5/docs/api/java/util/Set.html" title="class or interface in java.util">Set</A> <B>getResourcePaths</B>(<A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/String.html" title="class or interface in java.lang">String</A>&nbsp;path)</PRE>
<DL>
<DD>Returns a directory-like listing of all the paths to resources within the web application whose longest sub-path
 matches the supplied path argument. Paths indicating subdirectory paths end with a '/'. The returned paths are all 
 relative to the root of the web application and have a leading '/'. For example, for a web application 
 containing<br><br>

 /welcome.html<br>
 /catalog/index.html<br>
 /catalog/products.html<br>
 /catalog/offers/books.html<br>
 /catalog/offers/music.html<br>
 /customer/login.jsp<br>
 /WEB-INF/web.xml<br>
 /WEB-INF/classes/com.acme.OrderServlet.class,<br><br>

 getResourcePaths("/") returns {"/welcome.html", "/catalog/", "/customer/", "/WEB-INF/"}<br>
 getResourcePaths("/catalog/") returns {"/catalog/index.html", "/catalog/products.html", "/catalog/offers/"}.<br>
<P>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>path</CODE> - the partial path used to match the resources,
                                which must start with a /
<DT><B>Returns:</B><DD>a Set containing the directory listing, or null if there are no resources in the web application whose path
 begins with the supplied path.<DT><B>Since:</B></DT>
  <DD>Servlet 2.3</DD>