写法一:
<%
if(jbpmMgr.getTaskStringVaviable(task.getId(),"tran_desc")!=null &&!jbpmMgr.getTaskStringVaviable(task.getId(),"tran_desc").equals(""))
{
out.print("("+jbpmMgr.getTaskStringVaviable(task.getId(),"tran_desc")+")");
}
%>
写法二:
<%if(jbpmMgr.getTaskStringVaviable(task.getId(),"tran_desc")!=null && !jbpmMgr.getTaskStringVaviable(task.getId(),"tran_desc").equals(""))
{ %>
(<%=jbpmMgr.getTaskStringVaviable(task.getId(),"tran_desc")%>)
<%} %>
开始用的写法一,结果是null也会输出,就改成了写法二,说不出为啥要改成这样,结果是null不会输出,求原理