Struts2文件上传

public void preExecute()  
    {  
        if (httpServletRequest instanceof MultiPartRequestWrapper)  
        {  
            MultiPartRequestWrapper requestWrapper = (MultiPartRequestWrapper) httpServletRequest;  
            Enumeration<String> parameterNames = requestWrapper.getFileParameterNames();  
            while (parameterNames.hasMoreElements())  
            {  
                @SuppressWarnings("unused")  
                String paramterName = parameterNames.nextElement();  
                File[] files = requestWrapper.getFiles(paramterName);  
                if (null == files || files.length == 0)  
                {  
                    continue;  
                }  
                else if (files.length == 1)  
                {  
                    FileBean fileBean = new FileBean();  
                    fileBean.setAbsolutePath(files[0].getAbsolutePath());  
                    fileBean.setFileSize(files[0].length());  
                    fileBean.setFilename(requestWrapper.getFileNames(paramterName)[0]);  
                    this.fileMap.put(paramterName, fileBean);  
                }  
                else  
                {  
                    ArrayList<FileBean> list = new ArrayList();  
                    for (int i = 0; i < files.length; i++)  
                    {  
                        File file = files[i];  
                        FileBean fileBean = new FileBean();  
                        fileBean.setAbsolutePath(file.getAbsolutePath());  
                        fileBean.setFileSize(file.length());  
                        fileBean.setFilename(requestWrapper.getFileNames(paramterName)[i]);  
                        list.add(fileBean);  
                    }  
                    this.fileMap.put(paramterName, list);  
                }  
            }  
        }  
    }