有关文件上传的控件可能非常多，比如有用于学习的SmartUpload、性能非常好的COS组件、有Apache的FileUpload组件、有Struts的FormFile组件、有Spring上传文件，还有其他一些开发的控件等等。假如你是用Struts，那基于Struts FormFile组件应该是一个不错的选择。
Struts FormFile跟Struts ActionForm结合得非常好，使用起来也非常简单，但是，对于同时上传多个附件，那就有点麻烦了！不管怎么样，它还是一个好东西，关键看大家怎么看待他了！
第一步，我们创建一个新的Struts工程，创建一个FileUploadForm，FileUploadForm如下所示：
程序代码
package zizz.struts;
import org.apache.struts.action.ActionForm;
import org.apache.struts.upload.FormFile;
/**
* 基于Struts FormFile的文件上传.
* @author chen yuzhe
*
*/
public class FileUploadForm extends ActionForm{
/**
* serialVersionUID
*/
private static final long serialVersionUID = -7794872310588861856L;
/**
* 上传的文件
*/
private FormFile uploadFile;
public FormFile getUploadFile() {
return uploadFile;
}
public void setUploadFile(FormFile uploadFile) {
this.uploadFile = uploadFile;
}
}
第二步，创建一个Action，用于处理上传的文件及保存在服务器的路径，FileUploadAction文件内容如下
程序代码
package zizz.struts;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.upload.FormFile;
/**
* 文件上传的Action，该类用于处理FormFile及将上传的文件保存到磁盘的指定位置.
* @author ZIZZ
*
* @Create-Time:2007-12-26 下午03:35:37
*/
public class FileUploadAction extends Action {
/**
* 上传的文件保存在服务器的路径
*/
private static String UPLOAD_FILE_PATH = "c:/income/";
@Override
public ActionForward execute(ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response) throws Exception {
FileUploadForm uploadForm = (FileUploadForm)form;
//得到上传的文件
FormFile uploadFile = uploadForm.getUploadFile();
//得到文件名
String fileName = uploadFile.getFileName();
//得到文件大小
int fileSize = uploadFile.getFileSize();
System.out.println("FileName = " + fileName);
System.out.println("FileSize=" + fileSize);
boolean result = true;
try{
//得到文件的输入流
InputStream is = uploadFile.getInputStream();
//上传文件
uploadFile(fileName,is);
}catch(IOException ex){
ex.printStackTrace();
//假如上传文件失败，设置一个失败的标记位
result = false;
}
if(result){
return mapping.findForward("success");
} else {
return mapping.findForward("fail");
}
}
/**
* 上传文件
* @param fileName
* @param is
* @throws IOException
*/
private void uploadFile(String fileName,InputStream is) throws IOException{
OutputStream os = new FileOutputStream(UPLOAD_FILE_PATH + fileName);
//8k缓存数据
byte[] buffer = new byte[1024 * 8];
//设置读进缓存的字节数
int len;
while((len=is.read(buffer))!=-1){
//将缓存数据写入磁盘
os.write(buffer,0,len);
}
//关闭输出流
os.close();
//关闭输入流
is.close();
}
}
第三步，编写文件上传的jsp文件
程序代码
<%@ page language="java" contentType="text/html; charset=GBK"%>
<%@ taglib uri="http://struts.apache.org/tags-html" prefix="html" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>文件上传表单</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">
</head>
<body>
<html:form action="/upload" enctype="multipart/form-data">
上传文件：<html:file property="uploadFile"></html:file>
<html:submit value="上传文件"></html:submit>
</html:form>
</body>
</html>
第四步，配置struts-config.xml文件
程序代码
<?xml version="1.0" encoding="UTF-8"?>
<!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>
<data-sources />
<form-beans>
<form-bean name="fileUploadForm" type="zizz.struts.FileUploadForm"></form-bean>
</form-beans>
<global-exceptions />
<global-forwards />
<action-mappings>
<action path="/upload" name="fileUploadForm" scope="request" type="zizz.struts.FileUploadAction">
<forward name="success" path="/success.jsp" redirect="true"></forward>
<forward name="fail" path="/fail.jsp" redirect="true"></forward>
</action>
</action-mappings>
<message-resources parameter="zizz.struts.ApplicationResources" />
</struts-config>