过滤器解决中文乱码问题

用servlet过滤器解决中文乱码问题

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;

public class SetEncodingFilter implements Filter {
 protected String encoding = null;
 protected FilterConfig filterConfig = null;
 protected boolean ignore = true;
 public void destroy() {
  this.encoding = null;
  this.filterConfig = null;
 }
 public void doFilter(ServletRequest request, ServletResponse response,
   FilterChain chain) throws IOException, ServletException {
  if (ignore || (request.getCharacterEncoding() == null)) {
   request.setCharacterEncoding(selectEncoding(request));
  }
  chain.doFilter(request, response);
 }
 public void init(FilterConfig filterConfig) throws ServletException {

  this.filterConfig = filterConfig;
  this.encoding = filterConfig.getInitParameter("encoding");
  String value = filterConfig.getInitParameter("ignore");
  if (value == null)
   this.ignore = true;
  else if (value.equalsIgnoreCase("true")
    || value.equalsIgnoreCase("yes"))
   this.ignore = true;
  else
   this.ignore = false;
 }
 protected String selectEncoding(ServletRequest request) {
  return (this.encoding);
 }
 public FilterConfig getFilterConfig() {
  return filterConfig;
 }
 public void setFilterConfig(FilterConfig filterConfig) {
  this.filterConfig = filterConfig;
 }
}

web.xml对应配置如下：

 <filter>
  <filter-name>SetCharsetEncodingFilter</filter-name>
  <filter-class>filter.SetEncodingFilter</filter-class>
  <init-param>
   <param-name>encoding</param-name>
   <param-value>UTF-8</param-value>
  </init-param>
 </filter>
 <filter-mapping>
  <filter-name>SetCharsetEncodingFilter</filter-name>
  <url-pattern>/*</url-pattern>
 </filter-mapping>