servletcontext.java

windows下的JAVA虚拟机

     *
     * <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.
     *
     */

    public Servlet getServlet(String name) throws ServletException;
    
  
  
  
    

    /**
     *
     * @deprecated	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.
     *
     */
    
    public Enumeration getServlets();
    
    
    
    
    

    /**
     * @deprecated	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.
     *
     */
 
    public Enumeration getServletNames();
    
  
  
    
    
    /**
     *
     * Writes the specified message to a servlet log file, usually
     * an event log. The name and type of the servlet log file is 
     * specific to the servlet container.
     *
     *
     * @param msg 	a <code>String</code> specifying the 
     *			message to be written to the log file
     *
     */
     
    public void log(String msg);
    
    
    
    

    /**
     * @deprecated	As of Java Servlet API 2.1, use
     * 			{@link #log(String message, Throwable throwable)} 
     *			instead.
     *
     * <p>This method was originally defined to write an 
     * exception's stack trace and an explanatory error message
     * to the servlet log file.
     *
     */

    public void log(Exception exception, String msg);
    
    
    
    

    /**
     * Writes an explanatory message and a stack trace
     * for a given <code>Throwable</code> exception
     * to the servlet log file. The name and type of the servlet log 
     * file is specific to the servlet container, usually an event log.
     *
     *
     * @param message 		a <code>String</code> that 
     *				describes the error or exception
     *
     * @param throwable 	the <code>Throwable</code> error 
     *				or exception
     *
     */
    
    public void log(String message, Throwable throwable);
    
    
    
    
    
    /**
     * Returns a <code>String</code> containing the real path 
     * for a given virtual path. For example, the path "/index.html"
     * returns the absolute file path on the server's filesystem would be
     * served by a request for "http://host/contextPath/index.html",
     * where contextPath is the context path of this ServletContext..
     *
     * <p>The real path returned will be in a form
     * appropriate to the computer and operating system on
     * which the servlet container is running, including the
     * proper path separators. This method returns <code>null</code>
     * if the servlet container cannot translate the virtual path
     * to a real path for any reason (such as when the content is
     * being made available from a <code>.war</code> archive).
     *
     *
     * @param path 	a <code>String</code> specifying a virtual path
     *
     *
     * @return 		a <code>String</code> specifying the real path,
     *                  or null if the translation cannot be performed
     *			
     *
     */

    public String getRealPath(String path);
    
    


    /**
     * Returns the name and version of the servlet container on which
     * the servlet is running. 
     *
     * <p>The form of the returned string is 
     * <i>servername</i>/<i>versionnumber</i>.
     * For example, the JavaServer Web Development Kit may return the string
     * <code>JavaServer Web Dev Kit/1.0</code>.
     *
     * <p>The servlet container may return other optional information 
     * after the primary string in parentheses, for example,
     * <code>JavaServer Web Dev Kit/1.0 (JDK 1.1.6; Windows NT 4.0 x86)</code>.
     *
     *
     * @return 		a <code>String</code> containing at least the 
     *			servlet container name and version number
     *
     */

    public String getServerInfo();
    
    


    /**
     * Returns a <code>String</code> containing the value of the named
     * context-wide initialization parameter, or <code>null</code> if the 
     * parameter does not exist.
     *
     * <p>This method can make available configuration information useful
     * to an entire "web application".  For example, it can provide a 
     * webmaster's email address or the name of a system that holds 
     * critical data.
     *
     * @param	name	a <code>String</code> containing the name of the
     *                  parameter whose value is requested
     * 
     * @return 		a <code>String</code> containing at least the 
     *			servlet container name and version number
     *
     * @see ServletConfig#getInitParameter
     */

    public String getInitParameter(String name);
    
    


    /**
     * Returns the names of the context's initialization parameters as an
     * <code>Enumeration</code> of <code>String</code> objects, or an
     * empty <code>Enumeration</code> if the context has no initialization
     * parameters.
     *
     * @return 		an <code>Enumeration</code> of <code>String</code> 
     *                  objects containing the names of the context's
     *                  initialization parameters
     *
     * @see ServletConfig#getInitParameter
     */

    public Enumeration getInitParameterNames();
    
    

    /**
     * Returns the servlet container attribute with the given name, 
     * or <code>null</code> if there is no attribute by that name.
     * An attribute allows a servlet container to give the
     * servlet additional information not
     * already provided by this interface. See your
     * server documentation for information about its attributes.
     * A list of supported attributes can be retrieved using
     * <code>getAttributeNames</code>.
     *
     * <p>The attribute is returned as a <code>java.lang.Object</code>
     * or some subclass.
     * Attribute names should follow the same convention as package
     * names. The Java Servlet API specification reserves names
     * matching <code>java.*</code>, <code>javax.*</code>,
     * and <code>sun.*</code>.
     *
     *
     * @param name 	a <code>String</code> specifying the name 
     *			of the attribute
     *
     * @return 		an <code>Object</code> containing the value 
     *			of the attribute, or <code>null</code>
     *			if no attribute exists matching the given
     *			name
     *
     * @see 		ServletContext#getAttributeNames
     *
     */
  
    public Object getAttribute(String name);
    
    
    

    /**
     * Returns an <code>Enumeration</code> containing the 
     * attribute names available
     * within this servlet context. Use the
     * {@link #getAttribute} method with an attribute name
     * to get the value of an attribute.
     *
     * @return 		an <code>Enumeration</code> of attribute 
     *			names
     *
     * @see		#getAttribute
     *
     */

    public Enumeration getAttributeNames();
    
    
    
    
    /**
     *
     * Binds an object to a given attribute name in this servlet context. If
     * the name specified is already used for an attribute, this
     * method will replace the attribute with the new to the new attribute.
     * <p>If listeners are configured on the <code>ServletContext</code> the  
     * container notifies them accordingly.
     * <p>
     * If a null value is passed, the effect is the same as calling 
     * <code>removeAttribute()</code>.
     * 
     * <p>Attribute names should follow the same convention as package
     * names. The Java Servlet API specification reserves names
     * matching <code>java.*</code>, <code>javax.*</code>, and
     * <code>sun.*</code>.
     *
     *
     * @param name 	a <code>String</code> specifying the name 
     *			of the attribute
     *
     * @param object 	an <code>Object</code> representing the
     *			attribute to be bound
     *
     *
     *
     */
    
    public void setAttribute(String name, Object object);
    
    



    /**
     * Removes the attribute with the given name from 
     * the servlet context. After removal, subsequent calls to
     * {@link #getAttribute} to retrieve the attribute's value
     * will return <code>null</code>.

     * <p>If listeners are configured on the <code>ServletContext</code> the 
     * container notifies them accordingly.

     *
     *
     * @param name	a <code>String</code> specifying the name 
     * 			of the attribute to be removed
     *
     */

    public void removeAttribute(String name);
    
    /**
     * 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.
     *
     *
     * @return	    The name of the web application or null if no name has been declared in the deployment descriptor.
     * @since Servlet 2.3
     */
    
    public String getServletContextName();
}