private void classLoader() {
    try {
      // StatementGenerator
      Class.forName(StatementGenerator.class.getName());
      Class.forName(ASTVisitor.class.getName());
      Class.forName(SqlLexer.class.getName());
      Class.forName(CommonTokenStream.class.getName());
      Class.forName(IoTDBSqlParser.class.getName());
      // SourceRewriter
      Class.forName(SourceRewriter.class.getName());
      Class.forName(DistributionPlanContext.class.getName());
      // LogicalPlaner
      Class.forName(LogicalPlanVisitor.class.getName());
      Class.forName(LogicalQueryPlan.class.getName());
      // TsFileProcessor
      Class.forName(TsFileProcessor.class.getName());
    } catch (ClassNotFoundException e) {
      logger.error("load class error: ", e);
    }
  }
Generate a list for triggers that do not have jar on this node.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/service/DataNode.java