nocachetag.java

JSP设计（第三版）一书源代码 JSP设计（第三版）》得到了充分的修订和更新

package com.ora.jsp.tags;

import javax.servlet.http.*;
import javax.servlet.jsp.*;
import javax.servlet.jsp.tagext.*;

/**
 * This class is a custom action for setting response headers
 * that prevent the page from being cached by a browser or
 * proxy server.
 *
 * @author Hans Bergsten, Gefion software <[e-mail]>
 * @version 2.0
 */
public class NoCacheTag extends TagSupport {
    /**
     * Sets "no cache" response headers
     */
    public int doEndTag() throws JspException {
        HttpServletResponse response = 
            (HttpServletResponse) pageContext.getResponse();
        response.addHeader("Pragma", "No-Cache");
        response.setHeader("Cache-Control", "no-cache, no-store, must-revalidate");
	response.addHeader("Cache-Control", "pre-check=0, post-check=0");
        response.setDateHeader("Expires", 0);
        return EVAL_PAGE;
    }
}