Apache Commons 文件上传 - 流意外结束

The code which causes the trace looks fairly straight forward.

private Map<String, Object> getMap( ActionRequest request ) {

    HashMap<String, Object> parameters = new HashMap<String, Object>();
    if ( request == null ) {
        return parameters;
    }

    if ( request.getContentType() == null ) {
        return parameters;
    }

    try {
        if(PortletFileUpload.isMultipartContent(request)){
            DiskFileItemFactory factory = new DiskFileItemFactory();
            PortletFileUpload upload = new PortletFileUpload(factory);
            List<DiskFileItem> fileItems = upload.parseRequest(request);
            for( DiskFileItem fileItem : fileItems ) {
                String name = fileItem.getFieldName();
                //now set appropriate variable, populate hashtable
                if( fileItem.isFormField() ) {
                    String value = fileItem.getString( request.getCharacterEncoding() );
                    if( parameters.get( name ) == null ) {
                        String[] values = new String[1];
                        values[0] = value;
                        parameters.put( name, values );
                    } else {
                        Object prevobj = parameters.get( name );
                        if( prevobj instanceof String[] ) {
                            String[] prev = ( String[] ) prevobj;
                            String[] newStr = new String[prev.length + 1];
                            System.arraycopy(
                                    prev, 0, newStr, 0,
                                    prev.length
                            );
                            newStr[prev.length] = value;
                            parameters.put( name, newStr );
                        } else {
                            //now what? I think this breaks the standard.
                            throw new EatMyHatException(
                                    "file and input field with same name?"
                            );
                        }
                    }
                } else {
                    // Yes, we don't return FileParameter[] for multiple files of same name.  AFAIK, that's not allowed.
                    FileParameter fp = new FileParameter( fileItem );
                    parameters.put( name, fp );
                    files.add( fp );
                }
            }
        } else {
            // Not multipart
            return toObjectMap(request.getParameterMap());
        }
    } catch (FileUploadException e) {
        throw new RuntimeException(e);
    } catch (UnsupportedEncodingException e) {
        throw new RuntimeException(e);
    }
    return parameters;
}

让我们感到悲伤的是这一行:

List<DiskFileItem> fileItems = upload.parseRequest(request);