JEE过滤器可在WebSphere 8.5 Java 1.7下修改请求

Question

我有一个过滤器

public class CheckFilter implements Filter {

过滤器执行

@Override
    public void doFilter(ServletRequest req, ServletResponse res,FilterChain chain) throws IOException, ServletException {

        if(req instanceof HttpServletRequest && res instanceof HttpServletResponse){
            HttpServletRequest request      = (HttpServletRequest) req;
            HttpServletResponse response    = (HttpServletResponse) res;
            HttpServletRequestWrapper requestMod =    new ReqWrapper((HttpServletRequest) request);

            chain.doFilter(requestMod , response);
        }

我的目的是从查询的一部分网址中删除一个特定的值。     http：\ site \ page？a = 1＆b = 2＆c = 3;

我需要去除b及其值。

过滤后的网址必须传递给该链中没有该参数的其他过滤器。

public class MultisessionReqWrapper extends HttpServletRequestWrapper {

    private String param_to_strip = "b";

    public MultisessionReqWrapper(final HttpServletRequest request)
            throws IOException {
        super(request);
    }

根据Modify request parameter with servlet filter，我通过了所有带有调试的方法，但没有成功。

最重要的方法是那些。

@Override
    public java.lang.String getParameter(java.lang.String arg0) {
        if (StringUtils.equals(arg0, param_to_strip )) {
            return null;
        } else {
            String param = super.getParameter(arg0);
            return param;
        }
    }

    @Override
    public Map getParameterMap() {
        Map<String, String[]> pm = super.getParameterMap();
        pm.remove(param_to_strip );
        return pm;
    }

    @Override
    public Enumeration getParameterNames() {
        Enumeration<String> pn = super.getParameterNames();
        if (pn != null) {
            Vector<String> v = new Vector<>();
            while (pn.hasMoreElements()) {
                String string = (String) pn.nextElement();
                if (!StringUtils.equals(string, param_to_strip )) {
                    v.add(string);
                }
            }
            return (Enumeration) v;
        } else {
            return pn;
        }
    }

    @Override
    public java.lang.String[] getParameterValues(java.lang.String arg0) {
        if (StringUtils.equals(arg0, param_to_strip )) {
            return null;
        } else {
            String[] pv = super.getParameterValues(arg0);
            return pv;
        }
    }

    @Override
    public java.lang.String getQueryString() {
        StringBuilder requestURL = new StringBuilder(super.getRequestURL()
                .toString());
        String queryString = super.getQueryString();

        if (queryString == null) {
            return null;
        } else {
            try {
                String path = requestURL.append('?').append(queryString)
                        .toString();
                URI uri = new URI(path);
                UriBuilder uriBuilder = UriBuilder.fromUri(uri);
                URI newuri = uriBuilder.replaceQueryParam(param_to_strip ,
                        (Object[]) null).build();
                URL url = newuri.toURL();
                return url.getQuery();
                // url= new
            } catch (URISyntaxException e) {
                e.printStackTrace();
            } catch (MalformedURLException e) {
                e.printStackTrace();
            }

        }

        // removeParameterFromURI()
        return "";
    }

最后，它似乎通过保留原始值的方法。我是否也要覆盖这个？

public ServletRequest getRequest() {


        return super.getRequest();

    }