java.lang.NullPointerException: No FileItemFactory has been set 解决

使用ServletFileUpload()默认构造器创建未初始化的实例，需要以factory作为构造函数或者setFileItemFactory()方法对factory进行配置

1. // Create a factory for disk-based file items  
2. FileItemFactory factory = new DiskFileItemFactory();    
3. // Create a new file upload handler  
4. ServletFileUpload upload = new ServletFileUpload(factory);  

转载于:https://www.cnblogs.com/lqlhxblog/p/6545678.html