response.write(session.getAttribute("BranchName")提示错误!
The method write(Object) is undefined for the type HttpServletResponse

[解决办法]
改成这样吧

response.write((String)session.getAttribute("BranchName"))
[解决办法]
response.write 的参数 有 long int char[] String

session.getAttribute取出来的都是Object

需要根据你实际的类型转换到上面几种类型