public static Map<String, String> getFilterParams(Configuration conf, String confPrefix) {
    Map<String, String> filterConfigMap = new HashMap<>();
    for (Map.Entry<String, String> entry : conf) {
      String name = entry.getKey();
      if (name.startsWith(confPrefix)) {
        String value = conf.get(name);
        name = name.substring(confPrefix.length());
        filterConfigMap.put(name, value);
      }
    }
    return filterConfigMap;
  }
Constructs a mapping of configuration properties to be used for filter initialization. The
mapping includes all properties that start with the specified configuration prefix. Property
names in the mapping are trimmed to remove the configuration prefix.
@param conf       configuration to read
@param confPrefix configuration prefix
@return mapping of configuration properties to be used for filter initialization
hbase-rest/src/main/java/org/apache/hadoop/hbase/rest/filter/RestCsrfPreventionFilter.java