Java 之@WebFilter

一、参数说明

 二、代码示例

package filter;

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 javax.servlet.annotation.WebFilter;
import javax.servlet.annotation.WebInitParam;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@WebFilter(filterName = "login", urlPatterns = {"/admin/*"}, initParams = {@WebInitParam(name = "noLoginPath", value = "login.jsp;error.jsp;/login")})
public class JLoginFilter implements Filter{

    private FilterConfig config;
    
    @Override
    public void destroy() {
        
    }

    @Override
    public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws IOException, ServletException {
        //String method = req.getParameter("method");
        //System.out.println(method);
        HttpServletRequest request = (HttpServletRequest) req;
        HttpServletResponse response = (HttpServletResponse) resp;
        // 检查地址是否不验证
        String noLoginPaths = config.getInitParameter("noLoginPath");
        //System.out.println("不验证地址：" + noLoginPaths);
        //System.out.println("当前访问地址：" + request.getRequestURL());
        //System.out.println("当前访问地址getRequestURI：" + request.getRequestURI());
        //System.out.println("queryString：" + request.getQueryString());
        if (noLoginPaths != null) {
            String[] strArray = noLoginPaths.split(";");
            for (int i = 0; i < strArray.length; i++) {
                if (strArray[i] == null || "".equals(strArray[i])) {
                    continue;
                }

                if (request.getRequestURL().indexOf(strArray[i]) != -1) {
                    chain.doFilter(req, resp);
                    return;
                }
            }
        }

        //判断是否登录
        Object user = request.getSession().getAttribute("admin");
        if (user == null) {
            //chain.doFilter(req, resp);
            response.sendRedirect(request.getContextPath()+"/admin/login?method=Login");
        } else {
            chain.doFilter(req, resp);
        }
    }

    @Override
    public void init(FilterConfig conf) throws ServletException {
        config = conf;
    }

}