dwr过滤表单参数

[winds_]

大大们，求助，项目中使用的dwr，现在提交表单的之后，我想在后台把表单提交过来的数据进行校验，过滤掉一些非法字符，我是这样做的，写一个过滤器，过滤器里面对过来的ServletRequest request使用包装器进行重写里面的getParameter等方法，然后再把这个重写后的request传递下去，这样后面的dwr使用的request就是我重写后的，然后dwr获取表单数据的时候应该就会调用我重写的这这些getParameter等方法了，但是不知为什么这样不可行，打断点看，dwr的servlet没有调用到getParameter方法来获取数据
过滤器：
public class XssFilter implements Filter {
FilterConfig filterConfig = null;

public void init(FilterConfig filterConfig) throws ServletException {
this.filterConfig = filterConfig;
}

public void destroy() {
this.filterConfig = null;
}

public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {
chain.doFilter(new XssHttpServletRequestWrapper(
(HttpServletRequest) request), response);
}
}

包装器
public class XssHttpServletRequestWrapper extends HttpServletRequestWrapper {
public XssHttpServletRequestWrapper(HttpServletRequest servletRequest) {
super(servletRequest);
}
@Override
public String[] getParameterValues(String parameter) {
String[] values = super.getParameterValues(parameter);
if (values == null) {
return null;
}
int count = values.length;
String[] encodedValues = new String[count];
for (int i = 0; i < count; i++) {
encodedValues[i] = cleanXSS(values[i]);
}
return encodedValues;
}
@Override
public Map getParameterMap() {
// TODO Auto-generated method stub
return super.getParameterMap();
}

@Override
public String getParameter(String parameter) {
String value = super.getParameter(parameter);
if (value == null) {
return null;
}
return cleanXSS(value);
}

//@Override
// public String getHeader(String name) {
// String value = super.getHeader(name);
// if (value == null)
// return null;
// return cleanXSS(value);
// }

private String cleanXSS(String value) {
value = value.replaceAll("<", "& lt;").replaceAll(">", "& gt;");
value = value.replaceAll("\\(", "& #40;").replaceAll("\\)", "& #41;");
value = value.replaceAll("'", "& #39;");
value = value.replaceAll("eval\\((.*)\\)", "");
value = value.replaceAll("[\\\"\\\'][\\s]*javascript:(.*)[\\\"\\\']", "\"\"");
value = value.replaceAll("script", "");
return value;
}
}

[winds_]

自顶.......................