ceph/src/jaegertracing/thrift/lib/java/src/org/apache/thrift/meta_data/FieldMetaData.java

   1 /*
   2  * Licensed to the Apache Software Foundation (ASF) under one
   3  * or more contributor license agreements. See the NOTICE file
   4  * distributed with this work for additional information
   5  * regarding copyright ownership. The ASF licenses this file
   6  * to you under the Apache License, Version 2.0 (the
   7  * "License"); you may not use this file except in compliance
   8  * with the License. You may obtain a copy of the License at
   9  *
  10  *   http://www.apache.org/licenses/LICENSE-2.0
  11  *
  12  * Unless required by applicable law or agreed to in writing,
  13  * software distributed under the License is distributed on an
  14  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  15  * KIND, either express or implied. See the License for the
  16  * specific language governing permissions and limitations
  17  * under the License.
  18  */
  19
  20 package org.apache.thrift.meta_data;
  21
  22 import java.util.HashMap;
  23 import java.util.Map;
  24 import org.apache.thrift.TBase;
  25 import org.apache.thrift.TFieldIdEnum;
  26
  27 /**
  28  * This class is used to store meta data about thrift fields. Every field in a
  29  * a struct should have a corresponding instance of this class describing it.
  30  *
  31  */
  32 public class FieldMetaData implements java.io.Serializable {
  33   public final String fieldName;
  34   public final byte requirementType;
  35   public final FieldValueMetaData valueMetaData;
  36   private static Map<Class<? extends TBase>, Map<? extends TFieldIdEnum, FieldMetaData>> structMap;
  37
  38   static {
  39     structMap = new HashMap<Class<? extends TBase>, Map<? extends TFieldIdEnum, FieldMetaData>>();
  40   }
  41
  42   public FieldMetaData(String name, byte req, FieldValueMetaData vMetaData){
  43     this.fieldName = name;
  44     this.requirementType = req;
  45     this.valueMetaData = vMetaData;
  46   }
  47
  48   public static synchronized void addStructMetaDataMap(Class<? extends TBase> sClass, Map<? extends TFieldIdEnum, FieldMetaData> map){
  49     structMap.put(sClass, map);
  50   }
  51
  52   /**
  53    * Returns a map with metadata (i.e. instances of FieldMetaData) that
  54    * describe the fields of the given class.
  55    *
  56    * @param sClass The TBase class for which the metadata map is requested
  57    */
  58   public static synchronized Map<? extends TFieldIdEnum, FieldMetaData> getStructMetaDataMap(Class<? extends TBase> sClass){
  59     if (!structMap.containsKey(sClass)){ // Load class if it hasn't been loaded
  60       try{
  61         sClass.newInstance();
  62       } catch (InstantiationException e){
  63         throw new RuntimeException("InstantiationException for TBase class: " + sClass.getName() + ", message: " + e.getMessage());
  64       } catch (IllegalAccessException e){
  65         throw new RuntimeException("IllegalAccessException for TBase class: " + sClass.getName() + ", message: " + e.getMessage());
  66       }
  67     }
  68     return structMap.get(sClass);
  69   }
  70 }