英语翻译declarative transaction support,fault tolerance,and load

英语翻译
declarative transaction support,fault tolerance,and load balancing provided by EJB servers.
 Which Java data access technologies do your developers know?What level of database knowledge do your developers have?Will you need training?If your team has previous experience with database access,that might influence your selection of a database access technology.
With these types of questions in mind,let's discuss the pros and cons of each of the four data access options,starting with the most simple.
JavaServer Pages Tags for SQL
The JSP Standard Tag Library or JSTL,which is covered in Chapter 4,includes a set of JSP tags that allow you to access a database via SQL directly from your JSP pages.
The obvious advantage of the JSP tags for SQL is simplicity.It's very easy to query the database and to throw the results up on a web page.This is great for simple applications that need only to display database data on a web page and make simple database table updates–JSP tags for SQL work well.You can execute database queries.The tag executes an SQL query and returns a result set object which you can iterate over and display with other JSTL tags.You can also do database table updates.The tag executes an SQL update.
For larger projects,there are a couple of disadvantages to keep in mind.One disadvantage is that you must embed SQL queries with table and field names into your JSP pages.If database table and field names change,then you'll have to make the corresponding changes in your JSP files.For a small project,this might not be a big problem,but larger projects should consider other data access options.Other data access options,such as O/R frameworks and EJB,can provide some level of indirection so that changes to the database schema do not have as much of an effect on your application code.
Another disadvantage is updates.The JSP tags for SQL allow you to do updates on a database,but you have to build the SQL update string yourself.Again,for small projects with simple update needs,this might not be a problem,but larger projects should consider other data access options.Other data access options can provide infrastructure to make updates much easier to program.

交易宣示支持,容错,负载平衡提供的EJB服务器.其中Java数据获取技术,你知道开发商?什么样的知识数据库,你的开发商?你是否需要培训?如果你的团队有先前的经验,与数据库的访问,这可能会影响你选择一个数据库存取技术.与上述类型的疑问,让我们讨论利弊,每四个数据接入选项,先从最简单的.JavaServer Pages的标签用于SQL JSP中的标准标签库或服务器,其中包括在第4章,包括一组JSP的标签,让你进入一个数据库,经由SQL直接从你的JSP页面.明显的优势,JSP的标签SQL是归真.它很容易就能查询数据库,并把结果在一个网页.这是一个十分简单的应用程序只需要显示数据库的数据在网页上做出简单 数据库表更新- JSP的标记用于SQL的工作干好.你可以执行数据库查询.的标记执行SQL查询,并返回一个结果集对象中,你可以遍历并展示 与其他服务器标记.你也可以做数据库表的更新.的标签执行一条SQL更新.对于大型项目,有几项缺点,记在心里.不利之处是,你必须嵌入SQL查询表和字段名到你的JSP页面.如果数据库表和字段的名称改变,那您就必须作出相应的改变,在你的JSP文件.对于一个小项目,这可能不是一个大问题,但较大的项目,应考虑其他数据接入选项.其他数据接入选项,如澳/住宅框架和EJB ,可以提供某种程度的间接使改变数据库模式不一样了 对你的应用代码.另一个缺点是更新.JSP的标记用于SQL让你更新了数据库,但你已经建立的SQL字符串更新自己.再次,为小项目,简单的更新需求,这可能不是一个问题,但较大的项目,应考虑其他数据接入选项.其他数据接入选项可以提供基础设施,使更新更容易编程.