SpringMVC修改请求参数

@Order(1)
@WebFilter(filterName = "ParamFilter", urlPatterns = "/*")
@Component
public class ReqParamFilter implements Filter {

    @Override
    public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain)
            throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) req;
        ReqParamWrapper requestParameterWrapper = new ReqParamWrapper(request);
        Map extraParams1 = new HashMap();
        extraParams1.put("limit", req.getParameter("pageSize"));
        requestParameterWrapper.addParameters(extraParams1);
        chain.doFilter(requestParameterWrapper, resp);
    }

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        Filter.super.init(filterConfig);
    }

    @Override
    public void destroy() {
        Filter.super.destroy();
    }
}

public class ReqParamWrapper extends HttpServletRequestWrapper {

    private Map params = new HashMap();

    public ReqParamWrapper(HttpServletRequest request) {
        super(request);
        this.params.putAll(request.getParameterMap());
    }

    public ReqParamWrapper(HttpServletRequest request, Map extraParams) {
        this(request);
        addParameters(extraParams);
    }

    public void addParameters(Map extraParams) {
        for (Map.Entry entry : extraParams.entrySet()) {
            addParameter(entry.getKey(), entry.getValue());
        }
    }

    @Override
    public Enumeration getParameterNames() {
        Set set = params.keySet();
        if (set.size() > 0 & set != null) {
            return Collections.enumeration(set);
        } else {
            return super.getParameterNames();
        }
    }

    @Override
    public String getParameter(String name) {
        String[] values = params.get(name);
        if (values == null || values.length == 0) {
            return null;
        }
        return values[0];
    }

    @Override
    public String[] getParameterValues(String name) {
        return params.get(name);
    }

    public void addParameter(String name, Object value) {
        if (value != null) {
            if (value instanceof String[]) {
                params.put(name, (String[]) value);
            } else if (value instanceof String) {
                params.put(name, new String[]{(String) value});
            } else {
                params.put(name, new String[]{String.valueOf(value)});
            }
        }
    }
}