PreLoginFilter.java

package org.fireflow.demo.security;

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 org.apache.shiro.SecurityUtils;
import org.apache.shiro.subject.Subject;

/**
 * Servlet Filter implementation class PreLoginFilter
 */
public class PreLoginFilter implements Filter {

    /**
     * Default constructor. 
     */
    public PreLoginFilter() {
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see Filter#destroy()
	 */
	public void destroy() {
		// TODO Auto-generated method stub
	}

	/**
	 * @see Filter#doFilter(ServletRequest, ServletResponse, FilterChain)
	 */
	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
		// place your code here
		Subject subject = SecurityUtils.getSubject();
		if (subject!=null){
			try{
				subject.logout();
			}catch(Throwable e){
				
			}
		}
		// pass the request along the filter chain
		chain.doFilter(request, response);
	}

	/**
	 * @see Filter#init(FilterConfig)
	 */
	public void init(FilterConfig fConfig) throws ServletException {
		// TODO Auto-generated method stub
	}

}