学步园

<filter>
<filter-name>AMFSessionFilter </filter-name>
<filter-class>com.netop.forum.servlets.AMFSessionFilter </filter-class>
<filter>

<filter-mapping>
<filter-name>AMFSessionFilter </filter-name>
<servlet-name>AMFGatewayServlet </servlet-name>
<filter-mapping>

2. AMFSessionFilter的代码

/*
* Created on 1/07/2004
*/
package com.netop.forum.servlets;

import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.*;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
* @author Zombie
* @version 0.5
*/

public class AMFSessionFilter implements Filter
{
private static Log log = LogFactory.getLog(AMFSessionFilter.class);

public void init(FilterConfig config)
{
log.info("Init AMFSessionFilter filter");
}

public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws ServletException,IOException
{
AMFContext.setCurrentContext((HttpServletRequest)request, (HttpServletResponse)response);
chain.doFilter(request,response);
}

public void destroy()
{
log.info("Destory AMFSessionFilter filter");
}
}

3. AMFContext的代码

/*
* Created on 1/07/2004
*/
package com.netop.forum.servlets;

import javax.servlet.*;
import javax.servlet.http.*;
import com.netop.forum.business.*;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
* @author Zombie
* @version 0.5
*/
public class AMFContext
{

/**
* Context Attribute key for the connection the factory
*/
public final static String CONNECTION_FACTORY_KEY = "sqlMapFactory";

/**
* The log
*/
private static Log log = LogFactory.getLog(AMFContext.class);

/**
* ThreadLocal object for storing object in current thread.
*/
private static ThreadLocal tl = new ThreadLocal();

/**
* Set current context
*
* @param request The HttpRequest object
* @param response The HttpResponses object
*/
static public void setCurrentContext(HttpServletRequest request, HttpServletResponse response)
{
AMFContext c = getCurrentContext();
if (c == null)
{
c = new AMFContext(request,response);
tl.set(c);
}
else
{
c.setRequest(request);
c.setResponse(response);
}
}

/**
* Get current context value
* @return The current context
*/
static public AMFContext getCurrentContext()
{
return (AMFContext)tl.get();
}

//----------------------------------------------------------
//
// Class members
//
//----------------------------------------------------------

/**
* The http request object. The lifecycle of the request object is defined as the request
* scope. It may be reused in another incoming connection, so dont use it in another thread.
*/
private HttpServletRequest request;

/**
* The http response object. The lifecycle of the response object is defined as the request
* scope. Dont use it in another thread. Also dont write output to the response when it is
* used in the context, but you may get or set some response header when it is safe.
*/
private HttpServletResponse response;

/**
* The constructor is private, to get an instance of the AMFContext, please use
* getCurrentContext() method.
*
* @param request
* @param response
*/
private AMFContext (HttpServletRequest request, HttpServletResponse response)
{
this.request = request;
this.response = response;
}

/**
* Get request object
*
* @return Http request object
*/
public HttpServletRequest getRequest()
{
return request;
}

/**
* Set request object
*
* @param Http request object
*/
public void setRequest(HttpServletRequest request)
{
this.request = request;
}

/**
* Get response object
*
* @return Http response object
*/
public HttpServletResponse getResponse()
{
return response;
}

/**
* Set response object
*
* @param response Http response object
*/
public void setResponse(HttpServletResponse response)
{
this.response = response;
}

/**
* Get the servlet context
* @return
*/
public ServletContext getServletContext()
{
HttpSession session = this.getSession();
return session.getServletContext();
}

/**
* Get the current running session
* @return
*/
public HttpSession getSession()
{
return request.getSession();
}

/**
* Get an object stored in the session.
*
* @param attr Attribute Name
* @return The value stored under the attribute name.
*/
public Object getSessionAttribute(String attr)
{
HttpSession session = this.getSession();
return session.getAttribute(attr);
}

/**
* Store an object in the session.
*
* @param attr Attribute Name
* @param value The value.
*/
public void setSessionAttribute(String attr, Object value)
{
HttpSession session = this.getSession();
session.setAttribute(attr, value);
}

/**
* Get an object stored in the servlet context.
*
* @param attr Attribute Name
* @return The value stored under the attribute name.
*/
public Object getContextAttribute(String attr)
{
ServletContext sc = this.getServletContext();
return sc.getAttribute(attr);
}

/**
* Store an object in the servlet context.
*
* @param attr Attribute Name
* @param value The value.
*/
public void setContextAttribute(String attr, Object value)
{
ServletContext sc = this.getServletContext();
sc.setAttribute(attr,value);
}

/**
* Get an object stored in the current request.
*
* @param attr Attribute Name
* @return The value stored under the attribute name.
*/
public Object getRequestAttribute(String attr)
{
return request.getAttribute(attr);
}

/**
* Store an object in the current request.
*
* @param attr Attribute Name
* @param value The value.
*/
public void setRequestAttribute(String attr, Object value)
{
request.setAttribute(attr,value);
}

/**
* Get the connection factory from the servlet context. The connection factory is in the
* application scope.
*
* @return The connection factory for creating sqlMap objects.
*/
public ConnectionFactory getConnectionFactory()
{
ConnectionFactory factory =(ConnectionFactory)this.getContextAttribute(CONNECTION_FACTORY_KEY);
if (factory == null)
{
try
{
factory = new ConnectionFactory();
// factory is lazy instantiated, so we need to invoke it once to make sure it is ok.
factory.getSqlMap();
this.setContextAttribute(CONNECTION_FACTORY_KEY, factory);
}
catch (Throwable e)
{
log.fatal("Can not create connection factory: "+e.getMessage(), e);
}
}
return factory;
}

}

4. 如何在remote object中使用AMFContext

class YouRemoteService
{
public void serviceMethod()
{
AMFContext context = AMFContext.getCurrentContext();
HttpSession = context.getSession();
ServletContext = context.getServletContext();

HttpServletRequest request = context.getRequest();
HttpServletResponse response = context.getResponse();

context.setSessionAttribute("attr","value");
context.setContextAttribute("attr","value");

}
}

代码中有一小点bug,自己修正就OK了。

如果这种要求不是很严格的话，还有一种山寨的做法，就是我们监听Application的mouseMove事件，同时起一个Timer，如果过了规定的时间没有mouseMove事件触发，我们就让他重新登陆。