com.oreilly.servlet

类 CacheHttpServlet

java.lang.Object

javax.servlet.GenericServlet

javax.servlet.http.HttpServlet

com.oreilly.servlet.CacheHttpServlet

所有已实现的接口:

java.io.Serializable, javax.servlet.Servlet, javax.servlet.ServletConfig

public abstract class CacheHttpServlet
extends javax.servlet.http.HttpServlet

A superclass for HTTP servlets that wish to have their output cached and automatically resent as appropriate according to the servlet's getLastModified() method. To take advantage of this class, a servlet must:

• Extend CacheHttpServlet instead of HttpServlet
• Implement a getLastModified(HttpServletRequest) method as usual

This class uses the value returned by getLastModified() to manage an internal cache of the servlet's output. Before handling a request, this class checks the value of getLastModified(), and if the output cache is at least as current as the servlet's last modified time, the cached output is sent without calling the servlet's doGet() method.

In order to be safe, if this class detects that the servlet's query string, extra path info, or servlet path has changed, the cache is invalidated and recreated. However, this class does not invalidate the cache based on differing request headers or cookies; for servlets that vary their output based on these values (i.e. a session tracking servlet) this class should probably not be used.

No caching is performed for POST requests.

CacheHttpServletResponse and CacheServletOutputStream are helper classes to this class and should not be used directly.

This class has been built against Servlet API 2.2. Using it with previous Servlet API versions should work; using it with future API versions likely won't work.

版本:

0.93, 2004/06/25, added setCharacterEncoding() for servlets 2.4, 0.92, 2000/03/16, added synchronization blocks to make thread safe, 0.91, 1999/12/28, made support classes package protected, 0.90, 1999/12/19

作者:

Jason Hunter, Copyright © 1999

另请参阅:

序列化表格

构造器概要

构造器

构造器和说明
CacheHttpServlet()

方法概要

方法

限定符和类型	方法和说明
protected void	service(javax.servlet.http.HttpServletRequest req, javax.servlet.http.HttpServletResponse res)

从类继承的方法 javax.servlet.http.HttpServlet

doDelete, doGet, doHead, doOptions, doPost, doPut, doTrace, getLastModified, service

从类继承的方法 javax.servlet.GenericServlet

destroy, getInitParameter, getInitParameterNames, getServletConfig, getServletContext, getServletInfo, getServletName, init, init, log, log

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

构造器详细资料

CacheHttpServlet

public CacheHttpServlet()

方法详细资料

service

protected void service(javax.servlet.http.HttpServletRequest req,
           javax.servlet.http.HttpServletResponse res)
                throws javax.servlet.ServletException,
                       java.io.IOException

覆盖:

service 在类中 javax.servlet.http.HttpServlet

抛出:

javax.servlet.ServletException

java.io.IOException