过滤器的原理图:
第一步:新建包cn.java.filter ;
第二步:建立类EncodingFilter,实现Filter接口,编写过滤器。
public class EncodingFilter implements Filter { @Override public void doFilter(ServletRequest reqeust, ServletResponse response, FilterChain chain) throws IOException, ServletException { reqeust.setCharacterEncoding("utf-8"); response.setCharacterEncoding("utf-8"); response.setContentType("text/html;charset=utf-8"); chain.doFilter(reqeust, response); } } |
第三步:配置web.xml;过滤器放在Servlet前面。因为是先拦截。
<!-- 配置过滤器 --> <filter> <filter-name>encodingFilter</filter-name> <filter-class>cn.java.filters.EncodingFilter</filter-class> </filter> <filter-mapping> <filter-name>encodingFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> |