EncodeFilter编码过滤器

有时候web项目莫名的乱码问题很令人头疼，很好的一种解决方式就是用过滤器对WEB应用的HTTP请求响应做相应的编码处理。
CharsetFilter.java

package com.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.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;public class CharsetFilter implements Filter{    private FilterConfig config;    //初始化配置参数    private static final String INIT_PARAM_ENCODE="encode";    @Override    public void destroy() {    }    @Override    public void doFilter(ServletRequest request, ServletResponse response,            FilterChain chain) throws IOException, ServletException {        HttpServletRequest req = (HttpServletRequest) request;        HttpServletResponse resp = (HttpServletResponse) response;        String encode = config.getInitParameter(INIT_PARAM_ENCODE);        if(encode != null && !encode.isEmpty())        {            req.setCharacterEncoding(encode);        }        chain.doFilter(request, response);        if(encode != null && !encode.isEmpty())        {        resp.setCharacterEncoding(encode);        }    }    //初始化方法    @Override    public void init(FilterConfig config) throws ServletException {        this.config = config;    }}

web.xml配置：url-pattern路径下的所有jsp都将经过过滤。

 <filter>    <filter-name>CharsetFilter</filter-name>    <filter-class>com.filter.CharsetFilter</filter-class>    <init-param>        <param-name>encode</param-name>        <param-value>GBK</param-value>    </init-param>  </filter>  <filter-mapping>    <filter-name>CharsetFilter</filter-name>    <url-pattern>/*</url-pattern>  </filter-mapping>