content: /*
   * Copyright 1999-2018 Alibaba Group Holding Ltd.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package com.alibaba.csp.sentinel.adapter.servlet.config;
  
  import com.alibaba.csp.sentinel.adapter.servlet.CommonFilter;
  import com.alibaba.csp.sentinel.adapter.servlet.CommonTotalFilter;
  import com.alibaba.csp.sentinel.config.SentinelConfig;
  import com.alibaba.csp.sentinel.log.RecordLog;
  import com.alibaba.csp.sentinel.util.StringUtil;
  
  /**
   * The configuration center for Web Servlet adapter.
   *
   * @author leyou
   * @author zhaoyuguang
   */
  public final class WebServletConfig {
  
      public static final String WEB_SERVLET_CONTEXT_NAME = "sentinel_web_servlet_context";
  
      public static final String BLOCK_PAGE_URL_CONF_KEY = "csp.sentinel.web.servlet.block.page";
      public static final String BLOCK_PAGE_HTTP_STATUS_CONF_KEY = "csp.sentinel.web.servlet.block.status";
  
      private static final int HTTP_STATUS_TOO_MANY_REQUESTS = 429;
  
      /**
       * Get redirecting page when Sentinel blocking for {@link CommonFilter} or
       * {@link CommonTotalFilter} occurs.
       *
       * @return the block page URL, maybe null if not configured.
       */
      public static String getBlockPage() {
          return SentinelConfig.getConfig(BLOCK_PAGE_URL_CONF_KEY);
      }
  
      public static void setBlockPage(String blockPage) {
          SentinelConfig.setConfig(BLOCK_PAGE_URL_CONF_KEY, blockPage);
      }
  
      /**
       * <p>Get the HTTP status when using the default block page.</p>
       * <p>You can set the status code with the {@code -Dcsp.sentinel.web.servlet.block.status}
       * property. When the property is empty or invalid, Sentinel will use 429 (Too Many Requests)
       * as the default status code.</p>
       *
       * @return the HTTP status of the default block page
       * @since 1.7.0
       */
      public static int getBlockPageHttpStatus() {
          String value = SentinelConfig.getConfig(BLOCK_PAGE_HTTP_STATUS_CONF_KEY);
          if (StringUtil.isEmpty(value)) {
              return HTTP_STATUS_TOO_MANY_REQUESTS;
          }
          try {
              int s = Integer.parseInt(value);
              if (s <= 0) {
                  throw new IllegalArgumentException("Invalid status code: " + s);
              }
              return s;
          } catch (Exception e) {
              RecordLog.warn("[WebServletConfig] Invalid block HTTP status (" + value + "), using default 429");
              setBlockPageHttpStatus(HTTP_STATUS_TOO_MANY_REQUESTS);
          }
          return HTTP_STATUS_TOO_MANY_REQUESTS;
      }
  
      /**
       * Set the HTTP status of the default block page.
       *
       * @param httpStatus the HTTP status of the default block page
       * @since 1.7.0
       */
      public static void setBlockPageHttpStatus(int httpStatus) {
          if (httpStatus <= 0) {
              throw new IllegalArgumentException("Invalid HTTP status code: " + httpStatus);
          }
          SentinelConfig.setConfig(BLOCK_PAGE_HTTP_STATUS_CONF_KEY, String.valueOf(httpStatus));
      }
  
      private WebServletConfig() {}
  }
  