crazy_coder的专栏

1. Check null for result returned by get, because if the object specified by identifier id is not exist in db, null will be returned2. Check the list returned by hibernate, 2.1 check whether the l

In MSSQLServer, by default, user can‘t insert/assign/update value for identity column; SQLServer will do this for user automatically, so there is one problem caused that: what will do if  wants to ass

xml file is actualy like the following format:     PUBLIC "-//hibernate/hibernate mapping dtd 3.0//EN"     "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">in the hibernate configu

In Jsp and Servlet, when traverse between Jsp page and Servlet, there are two ways:1. using jsp:forward2. using response.sendRedirect(url)here is the summary of the each method:jsp:forward

The type Enum is imported by Java1.5, here are some of the notice about using Enum in Java1. Enum is actually one interface2. Consider Enum as one simple class with several pre-defined instance, s

In JavaScript, there are some meaningless variable/value, which means, in logic expression, those meaningless variables will return false for ever.Those meaningless variables include: NULL, 0, false

1. before invalidate the session, its necessary to check whether the session is still valid,HttpServletRequest supply one method called: isRequestedSessionIdValid()this method will check whether

Hibernate provide kinds of operation methods to save/update/delete object. here we just give one simple conclusion of those method and their difference: save/update/saveOrUpdatethose three metho

In sql server 2005, there is no support for array.when you print something using  print @dddvalue, when @dddvalue is null, there will be nothing printedcharindex(search, @src) will get the ind