CharacterEncodingFilter.java
 
package org.com.util;
 
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 CharacterEncodingFilter implements Filter {
 
    private String characterEncoding = null;
    private boolean enabled;
 
    @Override
    public void destroy() {
       // TODO Auto-generated method stub
       characterEncoding = null;
    }
 
    @Override
    public void doFilter(ServletRequest request, ServletResponse response,
           FilterChain chain) throws IOException, ServletException {
       // TODO Auto-generated method stub
       if (enabled || characterEncoding != null) {
           request.setCharacterEncoding(characterEncoding);
           response.setCharacterEncoding(characterEncoding);
       }
       chain.doFilter(request, response);
    }
 
    @Override
    public void init(FilterConfig config) throws ServletException {
       // TODO Auto-generated method stub
       characterEncoding = config.getInitParameter("characterEncoding");
       enabled = "true".equalsIgnoreCase(config.getInitParameter("enabled").trim());
    }
 
}
 
web.xml
<!-- 字符转码过滤器 -->
    <filter>
       <filter-name>CharacterEncodingFilter</filter-name>
       <filter-class>
           org.com.util.CharacterEncodingFilter
       </filter-class>
       <init-param>
           <param-name>characterEncoding</param-name>
           <param-value>UTF-8</param-value>
       </init-param>
       <init-param>
           <param-name>enabled</param-name>
           <param-value>true</param-value>
       </init-param>
    </filter>
    <filter-mapping>
       <filter-name>CharacterEncodingFilter</filter-name>
       <url-pattern>/*</url-pattern>
    </filter-mapping>