使用的主要jar包：commons-io-1.3.2.jar包;commons-fileupload-1.2.1.jar包；commons-lang-2.3.jar，在使用组件实现文件上传时候要注意前后台的一致性，注意在后台定义File文件对象名要与jsp页面中的file标签name名字一致，前台form标签属性一定要设置为enctype="multipart/form-data"，而且传输方式必须是post方式。不然后台不认为提交的是文件类型，而认为是普通表单的提交。

废话不多说看主要实现代码：前台jsp代码：

<form id="file_upload_id" name="file_upload_name" action="${ctx }/fileProcess/uploadTableFile" method="post" enctype="multipart/form-data">
 
<table width="100%"  border="0" align="center" cellpadding="0" cellspacing="0"  class="table_input">
  <tr>
  <td class="right">选择本地文件：</td><td colspan="5">
  <input type="file" size="20" id="file" name="file"/>
  <input type="hidden" name="tableid" value="<%=ids %>"/>
  <input type="hidden" name="tumid" value="${param.dum}" />
  </td></tr>
</table>
<div class="clear_10px"></div>
<table width="100%"  border="0" align="center" cellpadding="0" cellspacing="0"  class="table_button">
<tr><td align="left" class="btright"><input type="submit" value="上传" class="button_tj" onclick="getInfo()" /></td>
</tr>
</table>
</form>

后台Java代码：

import java.io.File;

import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;

import org.apache.commons.fileupload.servlet.ServletFileUpload;
import org.apache.commons.io.FileUtils;
import org.apache.commons.io.FilenameUtils;
import org.apache.struts2.ServletActionContext;

public class FileProcessAction extends BaseAction {

private FileDatumService filedatumService;
private AttachmentService attachmentService;
private AccountService accountservice;
private SystemService sysService;
private TDatumdetail detail;
private TDatum datum;
private Tablemanage tm;
public Integer id;
    
private File file;

private String fileContentType;

private String fileFileName;

private String savePath;

private String downloadFileName;
    public String uploadTableFile(){
    response.setContentType("text/xml;charset=UTF-8");
boolean isMultipart = ServletFileUpload.isMultipartContent(request);
String fileName = "";

try {
if (isMultipart) {
fileName =getFileFileName();
SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMddhhmmss");
String attaCode = sdf.format(new Date());
String suffix = FilenameUtils.getExtension(fileName);
String newName = attaCode.concat(".").concat(suffix);
String basepath = request.getRealPath("/");
System.out.println("ddd:"+getSavePath());
// 保存文件
FileUtils.copyFile(getFile(), new File(basepath+getSavePath()+"/"+newName));
// 保存数据库
Attachment atta = new Attachment();
atta.setAttaName(fileName);
atta.setCurrentName(newName);
atta.setUploadTime(new Date());

atta.setUrl("/upload/" + newName);
int id=Integer.valueOf(request.getParameter("tableid"));
Tablemanage  tabma=new Tablemanage();
   tabma.setTablefile(fileName);
accountservice.tableUpdateSingle(id,tabma);

id=attachmentService.addFileattachment(atta);

session.put("fileid", id);
session.put("uploadFileName", newName);
return SUCCESS;
}
} catch (Exception e) {
e.printStackTrace();
}
return "failure";
}
public AttachmentService getAttachmentService() {
return attachmentService;
}

public void setAttachmentService(AttachmentService attachmentService) {
this.attachmentService = attachmentService;
}

public File getFile() {
return file;
}

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

public TDatumdetail getDetail() {
return detail;
}
public void setDetail(TDatumdetail detail) {
this.detail = detail;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getFileContentType() {
return fileContentType;
}

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

public String getFileFileName() {
return fileFileName;
}

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

public String getSavePath() {
return savePath;
}

public void setSavePath(String savePath) {
this.savePath = savePath;
}

public void setDownloadFileName(String downloadFileName) {
this.downloadFileName = downloadFileName;
}

public String getDownloadFileName() {
return downloadFileName;
}
public FileDatumService getFiledatumService() {
return filedatumService;
}
public void setFiledatumService(FileDatumService filedatumService) {
this.filedatumService = filedatumService;
}
public AccountService getAccountservice() {
return accountservice;
}

public void setAccountservice(AccountService accountservice) {
this.accountservice = accountservice;
}
public SystemService getSysService() {
return sysService;
}
public void setSysService(SystemService sysService) {
this.sysService = sysService;
}
public TDatum getDatum() {
return datum;
}
public void setDatum(TDatum datum) {
this.datum = datum;
}
}

在truts.xml里面的action中可以配置要上传文件的路径

<action name="uploadTableFile" class="com.sunway.storage.action.FileProcessAction"
method="uploadTableFile">

<param name="savePath">/upload</param>

</action>