You receive a "The specified file or folder name is too long" error message when you create a new folder or a new document in a document library in SharePoint Portal Server or in Windows SharePoint Services
Symptoms
You find that there are limits to the lengths of folder names and file names in URLs when you do any one of the following things in Microsoft Office SharePoint Server 2007, in Microsoft Office SharePoint Portal Server 2003, or in Microsoft Windows SharePoint Services: Create a new folder in a document library Create a new document in a document library, or save an existing document in a document library by using a new name for the document Upload a document to a document library For example, when you try to create a new folder in a document library and the folder has a very long name, you receive the following error message: The specified file or folder name is too long. The URL path for all files and folders must be 260 characters or less (and no more than 128 characters for any single file or folder name in the URL). Please type a shorter file or folder name.Cause
This behavior occurs if the number of characters in the URL exceeds the maximum number of characters that is supported for URLs in SharePoint Server 2007, in SharePoint Portal Server 2003, and in Windows SharePoint Services. To determine the length of a URL, SharePoint Server 2007, SharePoint Portal Server 2003, and Windows SharePoint Services convert the string in the URL to Universal Character Set (UCS) Transformation Format 16 (UTF-16) format, and then count the number of 16-bit characters in the string. A URL that contains more than 260 characters is not supported. Additionally, a URL that contains one or more of the following components is not supported: A folder name that has more than 256 UCS-2 characters A file name that has more than 128 characters
用word统计功能计算文件名长度：把文件名复制后放入任意word文件中，然后选中要统计的部分之后点击“审阅”--“字符统计”即可知道占用字符数!