JavaWeb 编码过滤器及登陆拦截器的通用代码

编码过滤器

public class EncodingFilter implements Filter {
    private String encoding = "utf-8";
    public void init(FilterConfig filterConfig) throws ServletException {
        if(filterConfig.getInitParameter("encoding")!=null){
            encoding = filterConfig.getInitParameter("encoding");
        }
    }

    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest)servletRequest;
        HttpServletResponse response = (HttpServletResponse)servletResponse;
        request.setCharacterEncoding(encoding);
        response.setCharacterEncoding(encoding);
        filterChain.doFilter(request,response);
    }

    public void destroy() {
    }
}

web.xnl配置

 <filter>
        <filter-name>encodingfilter-name>
        <filter-class>com.imooc.oa.global.EncodingFilterfilter-class>
        <init-param>
            <param-name>encodingparam-name>
            <param-value>utf-8param-value>
        init-param>
    filter>
    <filter-mapping>
        <filter-name>encodingfilter-name>
        <url-pattern>/*url-pattern>
    filter-mapping>

登陆拦截器

import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

public class LoginInterceptor implements HandlerInterceptor {
    public boolean preHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o) throws Exception {

        String url = httpServletRequest.getRequestURI();
        if(url.toLowerCase().indexOf("login")>=0){
            return true;
        }

        HttpSession session = httpServletRequest.getSession();
        if(session.getAttribute("employee")!=null){
            return true;
        }
        httpServletResponse.sendRedirect("/to_login");
        return false;
    }

    public void postHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, ModelAndView modelAndView) throws Exception {

    }

    public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) throws Exception {

    }
}

在spring-mvc.xml中配置

    <mvc:interceptors>
        <mvc:interceptor>
            <mvc:mapping path="/**"/>
            <bean class="com.imooc.oa.global.LoginInterceptor"/>
        </mvc:interceptor>
    </mvc:interceptors>