public boolean execute() {
		boolean succeed = true;

		try {
			succeed = prepare();
			if (succeed) {
				succeed = before();
			}
			if (succeed) {
				succeed = run();
			}
			if (succeed) {
				succeed = after();
			}
		}
		catch (Exception e) {
		}
		finally {
			try {
				clean();
			}
			catch (Exception e2) {
			}
		}
		return succeed;
	}
Utility class helping to execute jdbc operations within a load session.
Provides a way to prepare, run and clean a main load command. Additionally
it can use a list of before and after commands which are execute before and after
of a main command. Clean command is executed last even if some of the other
commands fail.

@author Janne Valkealahti
extensions/spring-xd-extension-gpfdist/src/main/java/org/springframework/xd/greenplum/support/JdbcCommands.java