不知道对weblogic7有效没有。
在weblogic.xml文件的<jsp-descriptor>部分加入
 <jsp-descriptor>
       <jsp-param>
       <param-name>compilerSupportsEncoding</param-name>
                        <param-value>true</param-value>
         </jsp-param>
         <jsp-param>
                    <param-name>encoding</param-name>
                    <param-value>GBK</param-value>
          </jsp-param>
   </jsp-descriptor>