Крейн Д., Паскарелло Э., Джеймс Д,. AJAX в действии / Ajax в действии / Исходники примеров / ajaxinactioncode_03nov2005 / ch11 / server_src / src / com / manning / ajaxinaction / web / SecretHeaderSecurityFilter

package com.manning.ajaxinaction.web;

import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.http.HttpServletRequest;

import com.manning.ajaxinaction.security.Encrypter;

/**
* security filyter that checks the referrer header and only lets in values matching
* a given string or regexp
*
* @author dave
*/
public class SecretHeaderSecurityFilter extends GenericSecurityFilter {

private String headerName=null;
/* (non-Javadoc)
* @see javax.servlet.Filter#init(javax.servlet.FilterConfig)
*/
public void init(FilterConfig config) throws ServletException {
super.init(config);
headerName=config.getInitParameter("headerName");
}

/* (non-Javadoc)
* @see com.manning.ajaxinaction.web.GenericSecurityFilter#isValidRequest(javax.servlet.ServletRequest)
*/
protected boolean isValidRequest(ServletRequest request) {
boolean valid=true;
HttpServletRequest hrequest=(HttpServletRequest)request;
if (headerName!=null){
valid=false;
String headerVal=hrequest.getHeader(headerName);
Encrypter crypt=EncryptUtils.retrieve(hrequest);
if (crypt!=null){
valid=crypt.compare(headerVal);
}
}
return valid;
}

}