<!-- 配置文件上傳類型解析器 multipartResolver-->
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
  <!-- 設(shè)置上傳文件最大尺寸，單位為B -->
  <property name="maxUploadSize" value="5242880" />
</bean>

<!-- 1.在文件上傳解析時(shí)發(fā)現(xiàn)異常，此時(shí)還沒(méi)有進(jìn)入到Controller方法中 -->
<bean id="exceptionResolver" class= "org.springframework.web.servlet.handler.SimpleMappingExceptionResolver"> 
  <property name="exceptionMappings"> 
    <props> 
    <!-- 遇到MaxUploadSizeExceededException異常時(shí)，跳轉(zhuǎn)到error.jsp頁(yè)面 -->
    <prop key= "org.springframework.web.multipart.MaxUploadSizeExceededException">/error </prop> 
    </props> 
  </property>
</bean>

/**
 * 自定義異常處理器類
 */
public class ExceptionHandler implements HandlerExceptionResolver{
  /**
   * 處理上傳文件大小超過(guò)限制拋出的異常
   */
  @Override
  public ModelAndView resolveException(HttpServletRequest req,
      HttpServletResponse res, Object ob,Exception ex) {
    ModelAndView mv=new ModelAndView();
    //判斷異常類型，來(lái)跳轉(zhuǎn)不同頁(yè)面
    if (ex instanceof MaxUploadSizeExceededException){ 
      //指定錯(cuò)誤信息
      mv.addObject("errormessage", "上傳文件過(guò)大");
      //設(shè)置跳轉(zhuǎn)視圖
      mv.setViewName("userEdit");
      return mv;
    } 
    //其他異常
    return null;
  }
}

<!-- 2.配置自定義異常處理器類 -->
<bean class="com.itheima.exception.ExceptionHandler" />

<!-- 配置文件上傳類型解析器 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 {
    //判斷是否文件上傳
    if(request!=null && ServletFileUpload.isMultipartContent(request)) {
      ServletRequestContext ctx = new ServletRequestContext(request);
      //獲取上傳文件尺寸大小
      long requestSize = ctx.contentLength();
      if (requestSize > maxSize) {
        //當(dāng)上傳文件大小超過(guò)指定大小限制后，模擬拋出MaxUploadSizeExceededException異常
        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">
      <!-- 設(shè)定限制的文件上傳大小 -->
      <property name="maxSize" value="5242880"/>
    </bean>
  </mvc:interceptor>
</mvc:interceptors>

/**
 * 全局文件類型攔截器
 */
public class FileTypeInterceptor extends HandlerInterceptorAdapter {
  @Override
  public boolean preHandle(HttpServletRequest request, 
      HttpServletResponse response, Object handler)throws Exception {
    boolean flag= true;
    // 判斷是否為文件上傳請(qǐng)求
    if (request instanceof MultipartHttpServletRequest) {
      MultipartHttpServletRequest multipartRequest = 
          (MultipartHttpServletRequest) request;
      Map<String, MultipartFile> files = 
                    multipartRequest.getFileMap();
      Iterator<String> iterator = files.keySet().iterator();
      //對(duì)多部件請(qǐng)求資源進(jìn)行遍歷
      while (iterator.hasNext()) {
        String formKey = (String) iterator.next();
        MultipartFile multipartFile = 
               multipartRequest.getFile(formKey);
        String filename=multipartFile.getOriginalFilename();
        //判斷是否為限制文件類型
        if (! checkFile(filename)) {
          //限制文件類型，請(qǐng)求轉(zhuǎn)發(fā)到原始請(qǐng)求頁(yè)面，并攜帶錯(cuò)誤提示信息
          request.setAttribute("errormessage", "不支持的文件類型！");
          request.getRequestDispatcher("/WEB-INF/jsp/userEdit.jsp")
          .forward(request, response); 
          flag= false;
        } 
      }
    }
    return flag;
  }
  /**
   * 判斷是否為允許的上傳文件類型,true表示允許
   */
  private boolean checkFile(String fileName) {
    //設(shè)置允許上傳文件類型
    String suffixList = "jpg,gif,png,ico,bmp,jpeg";
    // 獲取文件后綴
    String suffix = fileName.substring(fileName.lastIndexOf(".")
        + 1, fileName.length());
    if (suffixList.contains(suffix.trim().toLowerCase())) {
      return true;
    }
    return false;
  }
}

<mvc:interceptors>
  <!-- 如果有多個(gè)攔截器，則按照順序進(jìn)行配置 -->
　　<mvc:interceptor>
    <!-- /**表示所有URL和子URL路徑 -->
    <mvc:mapping path="/**" />
    <!-- 配置自定義的文件上傳類型限制攔截器 -->
    <bean class="com.itheima.interceptor.FileTypeInterceptor" />
  </mvc:interceptor>
</mvc:interceptors>