forcelogintag.java

beginJsp2.0外文书籍源代码

package com.wrox.secure;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.PageContext;
import javax.servlet.jsp.tagext.TagSupport;

public class ForceLoginTag extends TagSupport 
{
  private String errorPage;
  
  public void setErrorPage(String errorPage)
  {
    this.errorPage = errorPage;
  }

  public int doEndTag() throws JspException
  {
    HttpSession session = pageContext.getSession();
    
    if(session.getAttribute("user") == null)
    {
      
      try
      {
        pageContext.forward(errorPage);
        return SKIP_PAGE;
      }
      catch(Exception ex)
      {
        throw new JspException(ex.getMessage());
      }
    }
    return EVAL_PAGE;
  }
  public void release()
  {
    errorPage = null;
  }
}