使用Filter对Request进行统一编码

 

package test.encoding;

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 SetCharacterEncoding implements Filter ...{
    protected String encoding=null;
    protected FilterConfig filterconfig=null;
    protected boolean ignore=true;
     public void destroy() ...{
        // TODO Auto-generated method stub

    }

    public void doFilter(ServletRequest request, ServletResponse response,
            FilterChain arg2) throws IOException, ServletException ...{
        if(ignore||(request.getCharacterEncoding()==null))...{
            String encoding=this.selectEncoding(request);
            if(encoding!=null)...{
                request.setCharacterEncoding(encoding);
            }
        }
        arg2.doFilter(request, response);

    }

    public void init(FilterConfig filterconfig) throws ServletException ...{
        this.filterconfig=filterconfig;
        String encoding=filterconfig.getInitParameter("encoding");
        String value=filterconfig.getInitParameter("ignore");
        if(value==null)
        ...{
            ignore=true;
        }
        else if(value.equalsIgnoreCase("true"))...{
            ignore=true;
        }
        else if(value.equalsIgnoreCase("yes"))...{
            ignore=true;
        }
        else...{
            ignore=false;
        }

    }
    public String selectEncoding(ServletRequest request)...{
        return (this.encoding);
    }

}

<filter>
  <filter-name>setCharacterEncoding</filter-name>
  <filter-class>test.encoding.SetCharacterEncoding</filter-class>
  <init-param>
    <param-name>encoding</param-name>
    <param-value>gb2312</param-value>
  </init-param>

</filter>
<filter-mapping>
  <filter-name>setCharacterEncoding</filter-name>
  <url-pattern>/*</url-pattern>
</filter-mapping>