String savepath = ServletActionContext.getServletContext().getRealPath("/upload");
System.out.println(savepath);
    try {
    File desc = new File(savepath,picFileName);
    //FileUtils.copyFile(pic, desc);  《--采用此种方法以下均可省略,较简单
    InputStream is = new FileInputStream(pic);
    OutputStream os = new FileOutputStream(desc);
    byte[] buf = new byte[1024];
    int len;
    while((len=is.read(buf))!=-1){
        os.write(buf);
    }
    is.close();
    os.close();
    } catch (Exception e) {
        e.printStackTrace();
    }

 

易错点:若写成--》is.read(buf)<0 将无法读取过来, 但是会在目标路径生成一个零字节文件!