LoginFilter.java:

import javax.servlet.FilterChain;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.ServletException;
import javax.servlet.FilterConfig;


/*
 * 
 * @author Ace
 * web.xml配置如下： 
 * <filter> 
 * <filter-name>login</filter-name>
 * <filter-class>
 * org.waityou.news.util.filters.LoginFilter
 * </filter-class>
 * </filter> 
 * <filter-mapping> 
 * <filter-name>login</filter-name>
 * <url-pattern>/manager/*</url-pattern> 
 * </filter-mapping>
 */
public class LoginFilter implements Filter {

    protected FilterConfig filterConfig;

    public void doFilter(final ServletRequest req, final ServletResponse res,
            FilterChain chain) throws IOException, ServletException {
        HttpServletRequest hreq = (HttpServletRequest) req;
        HttpServletResponse hres = (HttpServletResponse) res;
        String isLog = (String) hreq.getSession().getAttribute("isLog");
        if ((isLog != null) && ((isLog.equals("true")) || (isLog == "true")))//检查是否登录
        {
            chain.doFilter(req, res);
            return;
        } else
            hres.sendRedirect("/error.html");//如果没有登录，把视图派发到登录页面
    }

    public void destroy() {
        this.filterConfig = null;
    }

    public void init(FilterConfig config) {
        this.filterConfig = config;
    }

    public void setFilterConfig(final FilterConfig filterConfig) {
        this.filterConfig = filterConfig;
    }
}




SetCharacterEncodingFilter.java:

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;

/**
 * @author Ace 编码过滤，一律设置成UTF-8
 * 
 * web.xml中配置如下： 
 * <filter>
 * <filter-name>Set Character Encoding</filter-name>
 * <filter-class>
 * org.waityou.news.util.filters.SetCharacterEncodingFilter
 * </filter-class> 
 * </filter> 
 * <filter-mapping>
 * <filter-name>Set Character Encoding</filter-name> 
 * <url-pattern>/*</url-pattern>
 * </filter-mapping>
 */
public class SetCharacterEncodingFilter implements Filter {
    
    public void destroy() {}
    public void doFilter(ServletRequest request, ServletResponse response,
            FilterChain chain) throws IOException, ServletException {
        request.setCharacterEncoding("UTF-8");
        // 传递控制到下一个过滤器
        chain.doFilter(request, response);
    }
    
    public void init(FilterConfig filterConfig) throws ServletException {}

}