struts文件上传demo<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4."htt

//前端代码

<%@ page language="java" contentType="text/html; charset=gb2312"
	pageEncoding="gb2312"%>
<%@taglib prefix="s" uri="/struts-tags"%>
    
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>
	<head>
		<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
		<title>上传文件</title>
	</head>
	<body>
	<!-- 上传文件表单定义 -->
	<s:form action="upload" method="post" enctype="multipart/form-data">
		<tr>
	<!-- 上传文件标签定义 -->
	<td>上传文件:<s:file name="file"></s:file></td>
	</tr>
	<tr>
	<td>再次上传文件:<s:file name="file"></s:file></td>
	</tr>
	<tr>
	<td align="left"><s:submit name="submit" value="提交"></s:submit></td>
	</tr>
	</s:form>
	</body>
</html>

后台代码

package action;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.List;

import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionSupport;

//文件上传Action
public class UploadAction extends ActionSupport {
	//上传文件存放路径
	private final static String UPLOADDIR = "/upload";
	//上传文件集合
	private List<File> file;
	//上传文件名集合
	private List<String> fileFileName;
	//上传文件内容类型集合
	private List<String> fileContentType;

	public List<File> getFile() {
		return file;
	}

	public void setFile(List<File> file) {
		this.file = file;
	}

	public List<String> getFileFileName() {
		return fileFileName;
	}

	public void setFileFileName(List<String> fileFileName) {
		this.fileFileName = fileFileName;
	}

	public List<String> getFileContentType() {
		return fileContentType;
	}

	public void setFileContentType(List<String> fileContentType) {
		this.fileContentType = fileContentType;
	}

	public String execute() throws Exception {
		for (int i = 0; i < file.size(); i++) {
			//循环上传每个文件
			uploadFile(i);
		}
		return "success";
	}

	//执行上传功能
	private void uploadFile(int i) throws FileNotFoundException, IOException {
		try {
			InputStream in = new FileInputStream(file.get(i));

			String dir = ServletActionContext.getRequest().getRealPath(UPLOADDIR);

			File uploadFile = new File(dir, this.getFileFileName().get(i));

			OutputStream out = new FileOutputStream(uploadFile);

			byte[] buffer = new byte[1024 * 1024];

			int length;
			while ((length = in.read(buffer)) > 0) {
				out.write(buffer, 0, length);
			}

			in.close();
			out.close();
		} catch (FileNotFoundException ex) {
			ex.printStackTrace();
		} catch (IOException ex) {
			ex.printStackTrace();
		}

	}

}