code: public final void dropAll(CatalogAndSchema... schemas) throws DatabaseException {
          if ((schemas == null) || (schemas.length == 0)) {
              schemas = new CatalogAndSchema[] {
                  new CatalogAndSchema(getDatabase().getDefaultCatalogName(), getDatabase().getDefaultSchemaName())
              };
          }
  
          DropAllCommand dropAll = (DropAllCommand) CommandFactory.getInstance().getCommand("dropAll");
          dropAll.setDatabase(this.getDatabase());
          dropAll.setSchemas(schemas);
  
          try {
              dropAll.execute();
          } catch (CommandExecutionException e) {
              throw new DatabaseException(e);
          }
      }
docs: Drops all database objects in the passed schema(s).