在web.xml中配置以下內容：

<filter>

   <filter-name>Set Character Encoding</filter-name>
   <filter-class>filter.FilterEncoding</filter-class>

   <init-param>
       <param-name>encoding</param-name>
       <param-value>GBK</param-value>
   </init-param>

</filter>

<filter-mapping>
   <filter-name>Set Character Encoding</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>

再新建一個filter包，把這個程序寫進去， 就可以解決oracle中文亂碼問題了，別的什么都不用修改……

package filter;

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 FilterEncoding implements Filter 
{ 
 protected String encoding;          // 接收字符編碼
 protected boolean ignore;            // 是否忽略大小寫
 protected FilterConfig filterConfig; // 初始化配置

 public void init(FilterConfig filterConfig) throws ServletException 
 {
  // 從web.xml文件中讀取encoding的值
  encoding = filterConfig.getInitParameter("encoding"); 
  // 從web.xml文件中讀取ignore的值
  String value = filterConfig.getInitParameter("ignore"); 
  // 以下三種情況均為忽略大小寫
  if(value == null) 
  { 
   ignore = true; 
  }
  else if(value.equalsIgnoreCase("yes")) 
  { 
   ignore = true; 
  } 
  else if(value.equalsIgnoreCase("true")) 
  { 
   ignore = true; 
  } 
 } 
 // doFilter方法
 public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException 
 {
  if(ignore || request.getCharacterEncoding() == null) 
  {
   // 如果為空先從web.xml中得到
   String encoding = selectEncoding(request); 
   if(encoding != null) 
   {
    // 設置字符集編碼
    request.setCharacterEncoding(encoding); 
   }
  }
  // 繼續執行
  chain.doFilter(request, response); 
 } 
 // 得到字符編碼
 private String selectEncoding(ServletRequest request) 
 { 
  return encoding; 
 } 
 public void destroy() 
 { 
  
 } 
}