字符编码过滤器的一般写法

今天研究别人的代码的时候突然发现spring的org.springframework.web.filter包下居然有个CharacterEncodingFilter.java,汗.....以前都没注意呢!不过那个看起来有点麻烦,所以下面的这个过滤器比较简单实用
java 代码

public class CharacterEncodingFilter implements Filter {    
    private String edcoding=null;    
    private FilterConfig filterConfig=null;    
    private boolean ignore=true;    
   
    public void destroy() {    
         edcoding=null;    
         filterConfig=null;    
    }    
   
    public void doFilter(ServletRequest request, ServletResponse response,    
            FilterChain filterChain) throws IOException, ServletException {    
        if(ignore==true||request.getCharacterEncoding()==null){    
            String encoding=setCharacterEncoding(request);    
              if(encoding!=null){    
                request.setCharacterEncoding(encoding);    
                    
                }    
        }    
          filterChain.doFilter(request, response);    
    }    
   
    public void init(FilterConfig filterConfig) throws ServletException {    
        this.filterConfig=filterConfig;    
        this.edcoding=filterConfig.getInitParameter("encoding");    
        String value=filterConfig.getInitParameter("ignore");    
        if(value==null){    
            this.ignore=true;    
        }else if(value.equalsIgnoreCase("true")){    
            this.ignore=true;    
                
        }else{    
            this.ignore=false;    
        }    
            
   
    }    
    public String setCharacterEncoding(ServletRequest request){    
        return this.edcoding;    
    }    
}    

web.xml中加以下代码

xml 代码

<filter>   
        <filter-name>CharacterEncodingFilter</filter-name>   
        <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>   
        <init-param>   
            <param-name>encoding</param-name>   
            <param-value>UTF-8</param-value>   
        </init-param>   
    </filter>   
    <filter-mapping>   
        <filter-name>CharacterEncodingFilter</filter-name>   
        <url-pattern>/*</url-pattern>   
    </filter-mapping>