struts2的单个文件上传

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" 
    xmlns="http://java.sun.com/xml/ns/javaee" 
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
    http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
    
    <!-- struts2 framework -->
    <filter>
        <filter-name>struts</filter-name>
        <filter-class>org.apache.struts2.dispatcher.FilterDispatcher</filter-class>
    </filter>

    <filter>
        <filter-name>struts-cleanup</filter-name>
        <filter-class>org.apache.struts2.dispatcher.ActionContextCleanUp</filter-class>
    </filter>
    
    <filter-mapping>
        <filter-name>struts</filter-name>
        <url-pattern>*.do</url-pattern>
        <dispatcher>REQUEST</dispatcher>
        <dispatcher>FORWARD</dispatcher>
    </filter-mapping>

    <filter-mapping>
        <filter-name>struts-cleanup</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>    
    
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
</web-app>

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
    "http://struts.apache.org/dtds/struts-2.0.dtd">
 <struts>
     <include file="struts-default.xml" />        
     <!--方法一 -->
     <package name="uploadFile" extends="struts-default">
         <action name="upload" class="com.nn.upload.UploadAction" method="upload">
               <result name="success">/success.jsp</result>
               <result name="input">/index.jsp</result>
         </action>
     </package>
     <!--方法二 --> 
     <package name="uploadFile2" extends="struts-default">
         <action name="upload2" class="com.nn.upload.UploadAction" method="uploadByStream">    
             <param name="allowTypes">.bmp,.png,.gif,.jpeg,.jpg</param>        
               <param name="savePath">/upload</param> <!-- 保存的真实路径 -->
               <result name="success">/success.jsp</result>
               <result name="input">/index.jsp</result>
         </action>
     </package>
</struts>

struts.multipart.parser=jakarta
struts.multipart.saveDir=/temp
struts.multipart.maxSize=2097152
struts.i18n.encoding=utf-8
struts.locale=zh_CN
struts.action.extension=do
struts.custom.i18n.resources=globalMsg

public class UploadAction extends ActionSupport {
    private File file;
    private String  fileName;
    private String fileType;
    // 第二种方法中接受依赖注入的属性
    private String savePath;
    private String allowTypes;
    
    /**
     * 第一种方法，使用FileUtils从temp中复制到相关路径下面，结束后temp中的文件自动被清楚
     * @return
     */
    public String upload() {        
        String realpath = ServletActionContext.getServletContext().getRealPath("/upload");
        if (file != null) {
            String name = this.getFileName().substring(1);
            SimpleDateFormat  df = new SimpleDateFormat("yyyyMMddHHmmss");
            this.setFileName(df.format(new Date())+name); //文件名字+日期
            File savefile = new File(new File(realpath), this.getFileName());
            if (!savefile.getParentFile().exists())
                savefile.getParentFile().mkdirs();
            try {
                FileUtils.copyFile(file, savefile);
            } catch (IOException e) {
                e.printStackTrace();
            }
            ActionContext.getContext().put("message", "文件上传成功！");
        }
        return "success";
    }
    
    /**
     * 第二站方式，通过字节流来复制
     * @return 
     */
    public String uploadByStream(){
        // 判断是否允许上传
          String filterResult = findFileType(this.getAllowTypes().split(","));
          if (filterResult != null) {
           ActionContext.getContext().put("typeError","您要上传的文件类型不正确");
           return filterResult;
          }
          
          // 以服务器的文件保存地址和原文件名建立上传文件输出流
          FileOutputStream fos;
          FileInputStream fis;
          String realpath = ServletActionContext.getServletContext().getRealPath(this.getSavePath());
        try {
            String name = this.getFileName().substring(1);
            SimpleDateFormat  df = new SimpleDateFormat("yyyyMMddHHmmss");
            this.setFileName(df.format(new Date())+name); //文件名字+日期
            realpath = realpath +"\\"+this.getFileName();
            fos = new FileOutputStream(realpath);
            fis = new FileInputStream(this.getFile());
             byte[] buffer = new byte[1024];
              int len = 0;
              while ((len = fis.read(buffer)) > 0) {
               fos.write(buffer, 0, len);
              }
              fos.close();
              fis.close();
              return SUCCESS;
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }  
          return INPUT;
    }
    public String findFileType(String[] types) {
          String fileType = this.getFileType();
          for (String type : types) {              
              if (type.equals(fileType)) {
                return null;
              }
          }
          return INPUT;
    }        

     //省略get set 方法
}

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@taglib prefix="s" uri="/struts-tags"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>    
    <script type="text/javascript">
        function check(){
            var file = document.getElementById("file");    
            if(file != null){
                var fileType = file.value.substr(file.value.lastIndexOf(".")).toLowerCase(); //截取类型，如.jpg
                var fileName = file.value.substr(file.value.lastIndexOf("\\")); //截取文件名字，如：/01.png
                document.getElementById("fileName").value = fileName;
                document.getElementById("fileType").value = fileType;
                return true;
            }        
            alert("请选择文件");
            return false;
        }
    </script>
  </head>
  
  <body>
    <p>stuts 2 文件上传实例 </p>
    ${requestScope.typeError}
    <!-- 第一种方式上传链接：
    <form action="/upload.do" method="post" enctype="multipart/form-data" onsubmit="return check();">
     -->
      <form action="/upload2.do" method="post" enctype="multipart/form-data" onsubmit="return check();">
       上传文件：<input type="file" name="file" /><input type="submit"  value="上传"/>
           <input type="hidden" name="fileType" id="fileType"/>
          <input type="hidden" name="fileName" id="fileName"/>
      </form>
    
  </body>
</html>

 <body>
      ${requestScope.message}<br>
        文件名称：<input type="text" value="<s:property value="fileName"/>"/><br>   
         文件为：<img src="${pageContext.request.contextPath}/<s:property value="‘upload/‘+fileName"/>"><br>
    <s:debug></s:debug>
  </body>