ceph/src/arrow/java/flight/flight-core/src/main/java/org/apache/arrow/flight/RequestContext.java

   1 /*
   2  * Licensed to the Apache Software Foundation (ASF) under one or more
   3  * contributor license agreements.  See the NOTICE file distributed with
   4  * this work for additional information regarding copyright ownership.
   5  * The ASF licenses this file to You under the Apache License, Version 2.0
   6  * (the "License"); you may not use this file except in compliance with
   7  * the License.  You may obtain a copy of the License at
   8  *
   9  *    http://www.apache.org/licenses/LICENSE-2.0
  10  *
  11  * Unless required by applicable law or agreed to in writing, software
  12  * distributed under the License is distributed on an "AS IS" BASIS,
  13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14  * See the License for the specific language governing permissions and
  15  * limitations under the License.
  16  */
  17
  18 package org.apache.arrow.flight;
  19
  20 import java.util.Set;
  21
  22 /**
  23  * Tracks variables about the current request.
  24  */
  25 public interface RequestContext {
  26   /**
  27    * Register a variable and a value.
  28    * @param key the variable name.
  29    * @param value the value.
  30    */
  31   void put(String key, String value);
  32
  33   /**
  34    * Retrieve a registered variable.
  35    * @param key the variable name.
  36    * @return the value, or null if not found.
  37    */
  38   String get(String key);
  39
  40   /**
  41    * Retrieves the keys that have been registered to this context.
  42    * @return the keys used in this context.
  43    */
  44   Set<String> keySet();
  45
  46   /**
  47    * Deletes a registered variable.
  48    * @return the value associated with the deleted variable, or null if the key doesn't exist.
  49    */
  50   String remove(String key);
  51 }