struts2处理上传的文件

public abstract class ActionEngine extends ActionSupport implements ServletRequestAware{    private HttpServletRequest httpServletRequest;    public void setServletRequest(HttpServletRequest servletRequest)    {        this.httpServletRequest = servletRequest;    }    protected Map<String, Object> fileMap = new HashMap<String, Object>();    public void preExecute() throws Exception    {        if (httpServletRequest instanceof MultiPartRequestWrapper)        {            MultiPartRequestWrapper requestWrapper = (MultiPartRequestWrapper) httpServletRequest;            if (requestWrapper.hasErrors())            {                Collection<String> errors = requestWrapper.getErrors();                if (errors != null && !errors.isEmpty())                {                    Iterator iterator = errors.iterator();                    long maxSize = 0;                    if (requestWrapper.getAttribute("maxSize") != null)                    {                        maxSize = Long.parseLong(requestWrapper.getAttribute("maxSize")                                .toString());                        maxSize = maxSize / 1024 / 1024;                    }                    while (iterator.hasNext())                    {                        throw new XXXException;                    }                }                return;            }            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);                }            }        }    }}