public void read(org.apache.thrift.protocol.TProtocol iprot, TScan struct) throws org.apache.thrift.TException {
      org.apache.thrift.protocol.TField schemeField;
      iprot.readStructBegin();
      while (true)
      {
        schemeField = iprot.readFieldBegin();
        if (schemeField.type == org.apache.thrift.protocol.TType.STOP) { 
          break;
        }
        switch (schemeField.id) {
          case 1: // START_ROW
            if (schemeField.type == org.apache.thrift.protocol.TType.STRING) {
              struct.startRow = iprot.readBinary();
              struct.setStartRowIsSet(true);
            } else { 
              org.apache.thrift.protocol.TProtocolUtil.skip(iprot, schemeField.type);
            }
            break;
          case 2: // STOP_ROW
            if (schemeField.type == org.apache.thrift.protocol.TType.STRING) {
              struct.stopRow = iprot.readBinary();
              struct.setStopRowIsSet(true);
            } else { 
              org.apache.thrift.protocol.TProtocolUtil.skip(iprot, schemeField.type);
            }
            break;
          case 3: // TIMESTAMP
            if (schemeField.type == org.apache.thrift.protocol.TType.I64) {
              struct.timestamp = iprot.readI64();
              struct.setTimestampIsSet(true);
            } else { 
              org.apache.thrift.protocol.TProtocolUtil.skip(iprot, schemeField.type);
            }
            break;
          case 4: // COLUMNS
            if (schemeField.type == org.apache.thrift.protocol.TType.LIST) {
              {
                org.apache.thrift.protocol.TList _list26 = iprot.readListBegin();
                struct.columns = new java.util.ArrayList<java.nio.ByteBuffer>(_list26.size);
                @org.apache.thrift.annotation.Nullable java.nio.ByteBuffer _elem27;
                for (int _i28 = 0; _i28 < _list26.size; ++_i28)
                {
                  _elem27 = iprot.readBinary();
                  struct.columns.add(_elem27);
                }
                iprot.readListEnd();
              }
              struct.setColumnsIsSet(true);
            } else { 
              org.apache.thrift.protocol.TProtocolUtil.skip(iprot, schemeField.type);
            }
            break;
          case 5: // CACHING
            if (schemeField.type == org.apache.thrift.protocol.TType.I32) {
              struct.caching = iprot.readI32();
              struct.setCachingIsSet(true);
            } else { 
              org.apache.thrift.protocol.TProtocolUtil.skip(iprot, schemeField.type);
            }
            break;
          case 6: // FILTER_STRING
            if (schemeField.type == org.apache.thrift.protocol.TType.STRING) {
              struct.filterString = iprot.readBinary();
              struct.setFilterStringIsSet(true);
            } else { 
              org.apache.thrift.protocol.TProtocolUtil.skip(iprot, schemeField.type);
            }
            break;
          case 7: // BATCH_SIZE
            if (schemeField.type == org.apache.thrift.protocol.TType.I32) {
              struct.batchSize = iprot.readI32();
              struct.setBatchSizeIsSet(true);
            } else { 
              org.apache.thrift.protocol.TProtocolUtil.skip(iprot, schemeField.type);
            }
            break;
          case 8: // SORT_COLUMNS
            if (schemeField.type == org.apache.thrift.protocol.TType.BOOL) {
              struct.sortColumns = iprot.readBool();
              struct.setSortColumnsIsSet(true);
            } else { 
              org.apache.thrift.protocol.TProtocolUtil.skip(iprot, schemeField.type);
            }
            break;
          case 9: // REVERSED
            if (schemeField.type == org.apache.thrift.protocol.TType.BOOL) {
              struct.reversed = iprot.readBool();
              struct.setReversedIsSet(true);
            } else { 
              org.apache.thrift.protocol.TProtocolUtil.skip(iprot, schemeField.type);
            }
            break;
          case 10: // CACHE_BLOCKS
            if (schemeField.type == org.apache.thrift.protocol.TType.BOOL) {
              struct.cacheBlocks = iprot.readBool();
              struct.setCacheBlocksIsSet(true);
            } else { 
              org.apache.thrift.protocol.TProtocolUtil.skip(iprot, schemeField.type);
            }
            break;
          default:
            org.apache.thrift.protocol.TProtocolUtil.skip(iprot, schemeField.type);
        }
        iprot.readFieldEnd();
      }
      iprot.readStructEnd();

      // check for required fields of primitive type, which can't be checked in the validate method
      struct.validate();
    }
Returns true if field corresponding to fieldID is set (has been assigned a value) and false otherwise
hbase-thrift/src/main/java/org/apache/hadoop/hbase/thrift/generated/TScan.java