JavaWeb拦截器配置

页面请求拦截

import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class SysFilter implements Filter {
    public void init(FilterConfig filterConfig) throws ServletException {
        System.out.println("权限拦截启动");
    }

    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        HttpServletRequest request1 = (HttpServletRequest) request;
        HttpServletResponse response1 = (HttpServletResponse) response;
        if (request1.getSession().getAttribute(Constants.USER_SESSION)==null) {
            request1.setAttribute("error","请先登录！");
            request1.getRequestDispatcher("/login.jsp").forward(request1,response1);
        }else {
            chain.doFilter(request,response);
        }
    }

    public void destroy() {
        System.out.println("拦截器销毁");
    }
}

请求及响应编码配置

import javax.servlet.*;
import java.io.IOException;

public class CharacterEncodingFilter implements Filter {
    public void init(FilterConfig filterConfig) throws ServletException {
        System.out.println("过滤器初始化");
    }

    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        request.setCharacterEncoding("utf-8");
        response.setCharacterEncoding("utf-8");
        chain.doFilter(request,response);
    }

    public void destroy() {

    }
}