java.lang.NullPointerException: charsetNamejava.lang.String.(Unknown Source)com.jspsmart.upload.SmartUpload.upload(SmartUpload.java:234)org.apache.jsp.smartdemo.smartupload_005fdemo01_jsp._jspServi

(1)当表单封装之后,不可以使用request得到参数,可是不封装却又无法得到上传的文件。原因是表单被封装之后,里面传递的不再是文本数据,所以根本无法通过request.getParameter()方法取值。此时可以通过smartupload中提供的request对象完成,但是在使用这个方法之前,必须保证smartupload对象已经初始化成功。上传页面(使用的jar包是经过处理的,解

严重: Servlet.service() for servlet jsp threw exceptionjava.lang.IllegalStateException: getOutputStream() has already been called for this response at org.apache.catalina.connector.Response.getWriter(