struts1 文件上传大小的问题

struts1上传文件的大小限制是在struts-config.xml中设置的，当文件的size大于设定的数字后，报错。问题是actionform中的数据也丢了，请达人帮忙。

解决方案 »

  1.   

    struts1.x上传文件大小设置 一、web.xml配置，这里将文件上传配置为upload模块。 <?xml version="1.0" encoding="iso-8859-1"?> 
    <!DOCTYPE web-app 
      PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.2//EN" 
      "http://java.sun.com/j2ee/dtds/web-app_2_2.dtd"> 
    <web-app> 
     <display-name>Struts Blank Application</display-name> 
       
      <!-- Standard Action Servlet Configuration (with debugging) --> 
      <servlet> 
        <servlet-name>action</servlet-name> 
        <servlet-class>org.apache.struts.action.ActionServlet</servlet-class> 
        <init-param> 
          <param-name>config</param-name> 
          <param-value>/WEB-INF/struts-config.xml</param-value> 
        </init-param> 
        <init-param> 
          <param-name>config/upload</param-name> 
          <param-value>/WEB-INF/upload/struts-config.xml</param-value> 
        </init-param><init-param> 
          <param-name>debug</param-name> 
          <param-value>2</param-value> 
        </init-param> 
        <init-param> 
          <param-name>detail</param-name> 
          <param-value>2</param-value> 
        </init-param> 
        <load-on-startup>2</load-on-startup> 
      </servlet> 
      <!-- Standard Action Servlet Mapping --> 
      <servlet-mapping> 
        <servlet-name>action</servlet-name> 
        <url-pattern>*.do</url-pattern> 
      </servlet-mapping> 
      <!-- The Usual Welcome File List --> 
      <welcome-file-list> 
        <welcome-file>index.jsp</welcome-file> 
      </welcome-file-list> 
      <!-- Struts Tag Library Descriptors --> 
      <taglib> 
        <taglib-uri>/tags/struts-bean</taglib-uri> 
        <taglib-location>/WEB-INF/struts-bean.tld</taglib-location> 
      </taglib>   <taglib> 
        <taglib-uri>/tags/struts-html</taglib-uri> 
        <taglib-location>/WEB-INF/struts-html.tld</taglib-location> 
      </taglib>   <taglib> 
        <taglib-uri>/tags/struts-logic</taglib-uri> 
        <taglib-location>/WEB-INF/struts-logic.tld</taglib-location> 
      </taglib>   <taglib> 
        <taglib-uri>/tags/struts-nested</taglib-uri> 
        <taglib-location>/WEB-INF/struts-nested.tld</taglib-location> 
      </taglib>   <taglib> 
        <taglib-uri>/tags/struts-tiles</taglib-uri> 
        <taglib-location>/WEB-INF/struts-tiles.tld</taglib-location> 
      </taglib> </web-app> -------------------------------------------------------------------------------- 二、struts-config.xml配置和资源文件 -------------------------------------------------------------------------------- 
    <?xml version="1.0" encoding="iso-8859-1"?> <!DOCTYPE struts-config PUBLIC 
              "-//Apache Software Foundation//DTD Struts Configuration 1.2//EN" 
              "http://struts.apache.org/dtds/struts-config_1_2.dtd"> 
    <struts-config> 
      <form-beans> 
        <form-bean name="uploadForm" type="org.apache.struts.webapp.upload.UpLoadForm" /> 
      </form-beans> 
      <action-mappings> 
        <action path="/upload" forward="/selfile.jsp" /> 
        <!-- Upload Action --> 
        <action path="/uploadsAction"  
                type="org.apache.struts.webapp.upload.UpLoadAction"    
                name="uploadForm" scope="request" input="input"> 
          <forward name="input" path="/selfile.jsp" /> 
          <forward name="display" path="/display.jsp" /> 
        </action> 
      </action-mappings> 
      <!-- 这里设置上传文件的最大值。 -1 不限制大小。缺省值：-1 --> 
      <controller maxFileSize="2M" inputForward="true" /> 
      <message-resources parameter="org.apache.struts.webapp.upload.UploadResources"/> </struts-config>   资源文件：UploadResources_zh_CN.properties 
    maxLengthExceeded=已经超过了上传文件所允许的最大值。 
    maxLengthExplanation=注意：这个应用程序允许上传文件的最大值是2M。请看"/WEB-INF/upload/struts-config.xml" 文件更改这个值。 三、选择上传文件页面：selfile.jsp，如此访问此页面： 
    <html:link module="/upload" page="/upload.do"> 继续上传</html:link></h2> -------------------------------------------------------------------------------- 
    <%@ page contentType="text/html; charset=GBK" %> 
    <%@ page import="org.apache.struts.action.*, 
                     java.util.Iterator, 
                     org.apache.struts.Globals" %> 
    <%@ taglib uri="/tags/struts-bean" prefix="bean" %> 
    <%@ taglib uri="/tags/struts-html" prefix="html" %> 
    <%@ taglib uri="/tags/struts-logic" prefix="logic" %> 
    <logic:messagesPresent> 
       <ul> 
       <html:messages id="error"> 
          <li><bean:write name="error"/></li> 
       </html:messages> 
       </ul><hr /> 
    </logic:messagesPresent> 
    <html:html> <html:form action="uploadsAction.do" enctype="multipart/form-data"> 
    <html:file property="theFile"/> 
    <html:submit/> 
    </html:form> 
    </html:html> -------------------------------------------------------------------------------- 四、表单bean:  UpLoadForm.java -------------------------------------------------------------------------------- 
    package org.apache.struts.webapp.upload; 
    import javax.servlet.http.HttpServletRequest; 
    import org.apache.struts.action.*; 
    import org.apache.struts.upload.*; /** 
     * <p>Title:UpLoadForm</p> 
     * <p>Description: QRRSMMS </p> 
     * <p>Copyright: Copyright (c) 2004 jiahansoft</p> 
     * <p>Company: jiahansoft</p> 
     * @author wanghw 
     * @version 1.0 
     */ public class UpLoadForm extends ActionForm { 
      public static final String ERROR_PROPERTY_MAX_LENGTH_EXCEEDED = "org.apache.struts.webapp.upload.MaxLengthExceeded"; 
      protected FormFile theFile; 
      public FormFile getTheFile() { 
          return theFile; 
      } 
      public void setTheFile(FormFile theFile) { 
          this.theFile = theFile; 
      } 
       public ActionErrors validate( 
            ActionMapping mapping, 
            HttpServletRequest request) { 
                 
            ActionErrors errors = null; 
            //has the maximum length been exceeded? 
            Boolean maxLengthExceeded = 
                (Boolean) request.getAttribute( 
                    MultipartRequestHandler.ATTRIBUTE_MAX_LENGTH_EXCEEDED); 
                     
            if ((maxLengthExceeded != null) && (maxLengthExceeded.booleanValue())) { 
                errors = new ActionErrors(); 
                errors.add( 
                    ActionMessages.GLOBAL_MESSAGE , 
                    new ActionMessage("maxLengthExceeded")); 
                errors.add( 
                    ActionMessages.GLOBAL_MESSAGE , 
                    new ActionMessage("maxLengthExplanation")); 
            } 
            return errors;     } } 
    -------------------------------------------------------------------------------- 
    五、处理上传的文件：UpLoadAction.java  
    -------------------------------------------------------------------------------- 
    package org.apache.struts.webapp.upload; 
    import java.io.*; 
    import javax.servlet.http.*; 
    import org.apache.struts.action.*; 
    import org.apache.struts.upload.FormFile;  /** 
     * <p>Title:UpLoadAction</p> 
     * <p>Description: QRRSMMS </p> 
     * <p>Copyright: Copyright (c) 2004 jiahansoft</p> 
     * <p>Company: jiahansoft</p> 
     * @author wanghw 
     * @version 1.0 
     */ public class UpLoadAction extends Action { 
      public ActionForward execute(ActionMapping mapping, 
                                   ActionForm form, 
                                   HttpServletRequest request, 
                                   HttpServletResponse response) 
          throws Exception { 
           if (form instanceof UpLoadForm) {//如果form是UpLoadsForm 
               String encoding = request.getCharacterEncoding();        if ((encoding != null) && (encoding.equalsIgnoreCase("utf-8"))) 
            { 
                response.setContentType("text/html; charset=gb2312"); 
            } 
            UpLoadForm theForm = (UpLoadForm ) form; 
            FormFile file = theForm.getTheFile();//取得上传的文件 
            String contentType = file.getContentType();         String size = (file.getFileSize() + " bytes");//文件大小 
            String fileName= file.getFileName();//文件名 
            try { 
              InputStream stream = file.getInputStream();//把文件读入 
              String filePath = request.getRealPath("/");//取当前系统路径 
              ByteArrayOutputStream baos = new ByteArrayOutputStream(); 
              OutputStream bos = new FileOutputStream(filePath + "/" + 
                                                      file.getFileName()); 
                  //建立一个上传文件的输出流，将上传文件存入web应用的根目录。 
              //System.out.println(filePath+"/"+file.getFileName()); 
              int bytesRead = 0; 
              byte[] buffer = new byte[8192]; 
              while ( (bytesRead = stream.read(buffer, 0, 8192)) != -1) { 
                bos.write(buffer, 0, bytesRead);//将文件写入服务器 
              } 
              bos.close(); 
              stream.close(); 
            }catch(Exception e){ 
              System.err.print(e); 
            } 
            //request.setAttribute("dat",file.getFileName()); 
             request.setAttribute("contentType", contentType); 
             request.setAttribute("size", size); 
             request.setAttribute("fileName", fileName);         return mapping.findForward("display"); 
        } 
        return null; 
      } 
    } 
    ------------------------------------------------------------------------------------------ 五、成功页display.jsp  
    <%@ page contentType="text/html; charset=GBK" %> 
    <%@ page import="org.apache.struts.action.*, 
                     java.util.Iterator, 
                     org.apache.struts.Globals" %> 
    <%@ taglib uri="/tags/struts-html" prefix="html" %> 
    上传成功！上传信息如下： 
    <p> 
    <b>The File name:</b> <%= request.getAttribute("fileName") %> 
    </p> 
    <p> 
    <b>The File content type:</b> <%= request.getAttribute("contentType") %> 
    </p> 
    <p> 
    <b>The File size:</b> <%= request.getAttribute("size") %> 
    </p> 
    <hr /> 
    <hr /> 
    <html:link module="/upload" page="/upload.do"> 继续上传</html:link></h2> 
     六、测试 
     从本站下载整个目录结构TestStruts并放入tomcat的webapps目录下，在浏览器中输入： 
    http://127.0.0.1:8080/TestStruts/upload/upload.do 
      

  2.   

     报错是正常的，我要的是报错后的actionform里的值能被显示在页面上，my god
      

  3.   

    当然了，他是只检查HTTP头的，如果file的multipart的HTTP头的Content-Length大于设定，整个请求就不再读入ActionForm(populate)。你需要类似1F的方式，报错，让用户重新提交
      

  4.   

    struts1.2上传图片源代码(包含检查文件格式、限制文件大小功能)