@org.apache.thrift.annotation.Nullable
    public static _Fields findByThriftId(int fieldId) {
      switch(fieldId) {
        case 1: // MY_BOOL
          return MY_BOOL;
        case 2: // MY_BYTE
          return MY_BYTE;
        case 3: // MY_16BIT_INT
          return MY_16BIT_INT;
        case 4: // MY_32BIT_INT
          return MY_32BIT_INT;
        case 5: // MY_64BIT_INT
          return MY_64BIT_INT;
        case 6: // MY_DOUBLE
          return MY_DOUBLE;
        case 7: // MY_STRING
          return MY_STRING;
        case 8: // MY_BINARY
          return MY_BINARY;
        case 9: // MY_STRING_STRING_MAP
          return MY_STRING_STRING_MAP;
        case 10: // MY_STRING_ENUM_MAP
          return MY_STRING_ENUM_MAP;
        case 11: // MY_ENUM_STRING_MAP
          return MY_ENUM_STRING_MAP;
        case 12: // MY_ENUM_STRUCT_MAP
          return MY_ENUM_STRUCT_MAP;
        case 13: // MY_ENUM_STRINGLIST_MAP
          return MY_ENUM_STRINGLIST_MAP;
        case 14: // MY_ENUM_STRUCTLIST_MAP
          return MY_ENUM_STRUCTLIST_MAP;
        case 15: // MY_STRINGLIST
          return MY_STRINGLIST;
        case 16: // MY_STRUCTLIST
          return MY_STRUCTLIST;
        case 17: // MY_ENUMLIST
          return MY_ENUMLIST;
        case 18: // MY_STRINGSET
          return MY_STRINGSET;
        case 19: // MY_ENUMSET
          return MY_ENUMSET;
        case 20: // MY_STRUCTSET
          return MY_STRUCTSET;
        default:
          return null;
      }
    }
Find the _Fields constant that matches fieldId, or null if its not found.
serde/src/gen/thrift/gen-javabean/org/apache/hadoop/hive/serde2/thrift/test/MegaStruct.java