Spring MVC环境中文件上传大小和文件类型限制以及超大文件上传bug问题

<!-- 配置文件上传类型解析器 multipartResolver-->
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"> <!-- 设置上传文件最大尺寸，单位为B --> <property name="maxUploadSize" value="5242880" /> </bean>

<!-- 1.在文件上传解析时发现异常，此时还没有进入到Controller方法中 -->
<bean id="exceptionResolver" class= "org.springframework.web.servlet.handler.SimpleMappingExceptionResolver"> 
    <property name="exceptionMappings"> 
        <props> 
        <!-- 遇到MaxUploadSizeExceededException异常时，跳转到error.jsp页面  -->
        <prop key= "org.springframework.web.multipart.MaxUploadSizeExceededException">/error </prop> 
        </props> 
    </property>
</bean>

/**
 * 自定义异常处理器类
 */
public class ExceptionHandler implements HandlerExceptionResolver{
    /**
     * 处理上传文件大小超过限制抛出的异常
     */
    @Override
    public ModelAndView resolveException(HttpServletRequest req,
            HttpServletResponse res, Object ob,Exception ex) {
        ModelAndView mv=new ModelAndView();
        //判断异常类型，来跳转不同页面
        if (ex instanceof MaxUploadSizeExceededException){ 
            //指定错误信息
            mv.addObject("errormessage", "上传文件过大");
            //设置跳转视图
            mv.setViewName("userEdit");
            return mv;
        }  
        //其他异常
        return null;
    }
}

<!-- 2.配置自定义异常处理器类 -->
<bean class="com.itheima.exception.ExceptionHandler" />

<!-- 配置文件上传类型解析器 multipartResolver-->
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver" />

public class FileUploadInterceptor extends HandlerInterceptorAdapter {
    private long maxSize;

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        //判断是否文件上传
        if(request!=null && ServletFileUpload.isMultipartContent(request)) {
            ServletRequestContext ctx = new ServletRequestContext(request);
            //获取上传文件尺寸大小
            long requestSize = ctx.contentLength();
            if (requestSize > maxSize) {
                //当上传文件大小超过指定大小限制后，模拟抛出MaxUploadSizeExceededException异常
                throw new MaxUploadSizeExceededException(maxSize);
            }
        }
        return true;
    }
    public void setMaxSize(long maxSize) {
        this.maxSize = maxSize;
    }
}

<mvc:interceptors>
    <mvc:interceptor>
        <mvc:mapping path="/**"/>
        <bean class="com.itheima.interceptor.FileUploadInterceptor">
            <!-- 设定限制的文件上传大小 -->
            <property name="maxSize" value="5242880"/>
        </bean>
    </mvc:interceptor>
</mvc:interceptors>

/**
 * 全局文件类型拦截器
 */
public class FileTypeInterceptor extends HandlerInterceptorAdapter {
    @Override
    public boolean preHandle(HttpServletRequest request, 
            HttpServletResponse response, Object handler)throws Exception {
        boolean flag= true;
        // 判断是否为文件上传请求
        if (request instanceof MultipartHttpServletRequest) {
            MultipartHttpServletRequest multipartRequest = 
                    (MultipartHttpServletRequest) request;
            Map<String, MultipartFile> files = 
                                       multipartRequest.getFileMap();
            Iterator<String> iterator = files.keySet().iterator();
            //对多部件请求资源进行遍历
            while (iterator.hasNext()) {
                String formKey = (String) iterator.next();
                MultipartFile multipartFile = 
                              multipartRequest.getFile(formKey);
                String filename=multipartFile.getOriginalFilename();
                //判断是否为限制文件类型
                if (! checkFile(filename)) {
                    //限制文件类型，请求转发到原始请求页面，并携带错误提示信息
                    request.setAttribute("errormessage", "不支持的文件类型！");
                    request.getRequestDispatcher("/WEB-INF/jsp/userEdit.jsp")
                    .forward(request, response); 
                    flag= false;
                } 
            }
        }
        return flag;
    }
    /**
     * 判断是否为允许的上传文件类型,true表示允许
     */
    private boolean checkFile(String fileName) {
        //设置允许上传文件类型
        String suffixList = "jpg,gif,png,ico,bmp,jpeg";
        // 获取文件后缀
        String suffix = fileName.substring(fileName.lastIndexOf(".")
                + 1, fileName.length());
        if (suffixList.contains(suffix.trim().toLowerCase())) {
            return true;
        }
        return false;
    }
}

<mvc:interceptors>
    <!-- 如果有多个拦截器，则按照顺序进行配置 -->
　　<mvc:interceptor>
        <!-- /**表示所有URL和子URL路径 -->
        <mvc:mapping path="/**" />
        <!-- 配置自定义的文件上传类型限制拦截器 -->
        <bean class="com.itheima.interceptor.FileTypeInterceptor" />
    </mvc:interceptor>
</mvc:interceptors>