pagerequestwrapper.java

OS(OpenSymphony)的SiteMesh是一个用来在JSP中实现页面布局和装饰（layout and decoration）的框架组件

/* This software is published under the terms of the OpenSymphony Software
 * License version 1.1, of which a copy has been included with this
 * distribution in the LICENSE.txt file. */
package com.opensymphony.module.sitemesh.filter;

import javax.servlet.RequestDispatcher;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;

/**
 * Will wrap a request for the {@link RequestDispatcherWrapper}.
 *
 * @author <a href="mailto:[e-mail]">Joseph B. Ottinger</a>
 * @version $Revision: 1.4 $
 */
public class PageRequestWrapper extends HttpServletRequestWrapper {
    private static final boolean SUPPRESS_IF_MODIFIED_HEADER = true; //todo - pull this from a config file

    public PageRequestWrapper(HttpServletRequest request) {
        super(request);
    }

    public RequestDispatcher getRequestDispatcher(String s) {
        return new RequestDispatcherWrapper(super.getRequestDispatcher(s));
    }

    public String getHeader(String string) {
        // suppress 'if-modified-since' header, so that decorators can modify the response.
        if (SUPPRESS_IF_MODIFIED_HEADER && "IF-MODIFIED-SINCE".equalsIgnoreCase(string)) {
            return "";
        }
        else {
            return super.getHeader(string);
        }
    }
}