放入地图时出现非法状态异常

private void mergeQueryStrings(String url, Map parameterMap) {
    String queryString = getQueryString(url);
    if(queryString!=null){
        String [] params = queryString.split(\"&\");
        for(String param:params){
            parameterMap.put(param.split(\"=\")[0], param.split(\"=\")[1]);
        }
    }
}

private Map mergeQueryStrings(String url, Map parameterMap) {
    Map newParameterMap = new HashMap(parameterMap);
    String queryString = getQueryString(url);
    if(queryString!=null){
        String [] params = queryString.split(\"&\");
        for(String param:params){
            newParameterMap.put(param.split(\"=\")[0], param.split(\"=\")[1]);
        }
    }
    return newParameterMap;
}

Filter

HttpServletRequestWrapper