tomcat8 编写字符编码Filter过滤器无效问题

同事遇到编码问题时想做一个解决全站的字符编码过滤器，过滤器类和配置如下：

过滤器类：

package com.chaoxing.newspaper.web.filter;import java.io.IOException;import java.lang.reflect.InvocationHandler;import java.lang.reflect.Method;import java.lang.reflect.Proxy;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 CharacterEncodingFilter implements Filter {public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {System.out.println("过滤器执行"); final HttpServletRequest request = (HttpServletRequest) req;          HttpServletResponse response = (HttpServletResponse) res;                    //解决post请求的中文乱码          request.setCharacterEncoding("UTF-8");          response.setCharacterEncoding("UTF-8");          response.setContentType("text/html;charset=UTF-8");chain.doFilter((ServletRequest) Proxy.newProxyInstance(this.getClass().getClassLoader(), request.getClass().getInterfaces(), new InvocationHandler(){@Overridepublic Object invoke(Object proxy, Method method, Object[] args)throws Throwable {String methodname = method.getName();  //拿到当前的方法              if(methodname.equals("getParameter")){                  //执行request.getparameter获取结果                  String value = (String) method.invoke(request, args);                  if(value==null){                      return null;                  }                  if(!request.getMethod().equalsIgnoreCase("get")){ //判断是为get请求                      return value;                  }                  System.out.println(value+"|||||");                //转换编码返回                  value = new String(value.getBytes("UTF-8"),"UTF-8");                 System.out.println(value+"=======");                return value;              }              //交给request执行请求              return method.invoke(request, args);              }  } ), res);}public void init(FilterConfig fConfig) throws ServletException {System.out.println("过滤器初始化");}@Overridepublic void destroy() {System.out.println("过滤器完成");}}

过滤器配置：

 <!--解决全站乱码的filter    -->  <filter>  <filter-name>CharacterEncoding</filter-name>  <filter-class>com.XXX.web.filter.CharacterEncodingFilter</filter-class>  </filter>  <filter-mapping>  <filter-name>CharacterEncoding</filter-name>  <url-pattern>/*</url-pattern>  </filter-mapping>

       但是在前端form的提交方式是get的情况下，得到的仍然是乱码。

              刚开始一直纠结于过滤器是不是写错了，编码集是不是写错了，但是经过测试，并没有错，过滤器正常运行，

       最后把value.getByte("iso-8859-1","utf-8")  改为 value.getByte("utf-8","utf-8")后台就能得到值，不再是乱码了。最后百度了下，

      说tomcat8默认的编码集是utf-8，tomcat8之前默认的编码集是iso-8859-1,恍然大悟......

总结：tomcat7及其版本之前默认的编码集是iso-8859-1，tomcat8默认的字符集已经是UTF-8，所以不再需要为request.getParameter()的结果进行转码，不需要编码编码过滤器类了