Struts中上传文件需要注意的地方
今天突然想研究下Struts的上传功能，没想到搞了两个小时才搞出来，卡在一个地方，总是报错说参数类型转化异常，结果我改动了下页面，却又神出鬼没的上传成功了，赶紧记录下首先是web.xml中的配置，我个人喜欢每次弄个字符过滤器，以免出错
<filter><filter-name>filter</filter-name><filter-class>com.wujintao.dao.SetCharacterEncodingFilter</filter-class><init-param><param-name>encode</param-name><param-value>utf-8</param-value></init-param></filter><filter-mapping><filter-name>filter</filter-name><url-pattern>/*</url-pattern></filter-mapping><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>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> <welcome-file-list> <welcome-file>index.jsp</welcome-file></welcome-file-list>
struts-config.xml中的配置，挺奇怪的最后两行必须得配上
<struts-config> <!-- ================================================ Form Bean Definitions --> <form-beans> <form-bean name="uploadForm" type="com.javacrazyer.web.formbean.UploadForm"/> </form-beans> <!-- =========================================== Action Mapping Definitions --> <action-mappings><action path="/upload" name="uploadForm" type="com.javacrazyer.web.action.UploadAction"><forward name="succ" path="/succ.jsp"/><forward name="fail" path="/failure.jsp"/></action> </action-mappings> <controller bufferSize="8192" maxFileSize="1M" /> <message-resources parameter="msgs"/></struts-config>
其次就是业务逻辑的代码了，在这之前我必须说下，这个Struts的上传用到的关键点就是自己自带的FormFile类了，因此在FormBean里面应该配上一个FormFile类型的属性
private String description; //文件的描述private FormFile file;//文件具体内容对应的实例public String getDescription() {return description;}public void setDescription(String description) {this.description = description;}public FormFile getFile() {return file;}public void setFile(FormFile file) {this.file = file;}
业务逻辑处理代码
//具体业务流程处理方法，由Struts框架回调public ActionForward execute(ActionMapping mapping, ActionForm form,HttpServletRequest request, HttpServletResponse response)throws Exception { String toURL = "succ";//取数据UploadForm uForm = (UploadForm)form; String desc = uForm.getDescription();System.out.println("description==" + desc); FormFile ff = uForm.getFile(); if(ff == null){toURL = "fail";return mapping.findForward(toURL);}System.out.println("文件名：" + ff.getFileName());System.out.println("内容类型：" + ff.getContentType());System.out.println("文件大小：" + ff.getFileSize() + "字节"); BufferedInputStream bis = new BufferedInputStream(ff.getInputStream()); //目标路径String destPath = this.getServlet().getServletContext().getRealPath("/files");System.out.println(destPath+"===============================");BufferedOutputStream bos = null; try{bos = new BufferedOutputStream(new FileOutputStream(destPath + "/" + ff.getFileName())); //从源文件中取数据，写到目标文件中byte [] buff = new byte; for(int len = -1; (len = bis.read(buff)) != -1;){bos.write(buff, 0, len);} bos.flush(); }catch(IOException ie){ie.printStackTrace();toURL = "fail";}finally{if(bis != null){try{bis.close();}catch(IOException ie){ie.printStackTrace();}}if(bos != null){try{bos.close();}catch(IOException ie){ie.printStackTrace();}}} return mapping.findForward(toURL); }
接下来我要说的，大家都猜到了肯定是JSP页面的上传表单了，这里就是卡住我的罪魁祸首
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%><%@ taglib uri="http://jakarta.apache.org/struts/tags-html" prefix="html" %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html><head> <title>My JSP 'index.jsp' starting page</title><meta http-equiv="pragma" content="no-cache"><meta http-equiv="cache-control" content="no-cache"><meta http-equiv="expires" content="0"> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"><meta http-equiv="description" content="This is my page"><!--<link rel="stylesheet" type="text/css" href="styles.css">--></head><body> <html:form action="upload.do" enctype="multipart/form-data"> <html:text property="description"></html:text><html:file property="file"/> <html:submit/> </html:form> </body></html>
为什么说它是罪魁祸首呢，因为一直都认为<input type="file" />是最佳的上传表单，谁知道我找了大半天，竟然出现在这里的它必须是STRUTS标签的表单元素，郁闷！！！深刻的教训啊。
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