<filter>
   <filter-name>CharaterencodeFilter</filter-name>
   <filter-class>com.CharaterEncodeFilter</filter-class>
</filter>
<filter-mapping>
   <filter-name>CharaterencodeFilter</filter-name>
   <url-pattern>/*</url-pattern>
</filter-mapping>
 
放在web.xml里 
相应的类也给你
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 org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter;
public class CharaterEncodeFilter implements Filter {
 private FilterConfig config = null;
 
 
 public void destroy() {
  this.config = config;
 }
 
 public void doFilter(ServletRequest request, ServletResponse response,FilterChain chain) throws IOException, ServletException {
  
      request.setCharacterEncoding("UTF-8");
      response.setCharacterEncoding("UTF-8");
      chain.doFilter(request, response);
 }
 
 public void init(FilterConfig arg0) throws ServletException {
  config = null;
 }
 
 
 
}