Struts2中实现文件上传的功能

1、首先得配置一下Struts得配置文件struts-xml:

 <?xml version="1.0" encoding="UTF-8" ?>
 <!DOCTYPE struts PUBLIC
     "-//Apache Software Foundation//DTD Struts Configuration 2.1.7//EN"
     "http://struts.apache.org/dtds/struts-2.1.7.dtd">

 <struts>
     <!-- 设置可否动态调用方法 -->
     <constant name="struts.enable.DynamicMethodInvocation" value="true"/>

     <!-- 设置访问路径的后缀名 -->
     <constant name="struts.action.extension" value="do,action"/>

     <!-- 设置上传文件的最大值  10M左右-->
     <constant name="struts.multipart.maxSize" value="10701096"/>

     <!--
         上传单个文件
      -->
     <package name="uploadfile" namespace="/uploadfile" extends="struts-default">
            <action name="uploadfile" class="it.web.action.UploadFileAction" method="execute">
                <result name="success">/WEB-INF/demo/uploadfile.jsp</result>
            </action>
     </package>

     <!--
         上传多个文件
     -->
     <package name="uploadfiles" namespace="/uploadfiles" extends="struts-default">
            <action name="uploadfiles" class="it.web.action.UploadFileAction" method="execute">
                <result name="success">/WEB-INF/demo/uploadfiles.jsp</result>
            </action>
     </package>

 </struts>

2、对应的action类为：

 package it.web.action;

 import java.io.File;
 import org.apache.commons.io.FileUtils;
 import org.apache.struts2.ServletActionContext;

 import com.opensymphony.xwork2.ActionContext;

 public class UploadFileAction {
     //上传单个文件字段
     private File image;  //文件(必须要和表单的name属性值一样)
     private String imageFileName;  //文件名称(表单的name属性值+FileName)
     private String imageContentType;//得到上传文件的类型(表单的name属性值+ContentType)

     //上传多个文件的字段
     private File[] images;
     private String[] imageFileNames;
     private String[] imagesContentType;
     public File getImage() {
         return image;
     }
     public void setImage(File image) {
         this.image = image;
     }

     public String getImageFileName() {
         return imageFileName;
     }
     public void setImageFileName(String imageFileName) {
         this.imageFileName = imageFileName;
     }

     public String getImageContentType() {
         return imageContentType;
     }
     public void setImageContentType(String imageContentType) {
         this.imageContentType = imageContentType;
     }

 /*************************************************************************/
     public File[] getImages() {
         return images;
     }
     public void setImages(File[] images) {
         this.images = images;
     }

     public String[] getImageFileNames() {
         return imageFileNames;
     }
     public void setImageFileNames(String[] imageFileNames) {
         this.imageFileNames = imageFileNames;
     }

     public String[] getImagesContentType() {
         return imagesContentType;
     }
     public void setImagesContentType(String[] imagesContentType) {
         this.imagesContentType = imagesContentType;
     }

     /*
      * 上传单个文件
      */
     public String execute() throws Exception{
         //image
         /*
          *   得到上传文件的真实路径
          */
         String realpath = ServletActionContext.getServletContext().getRealPath("/image");
         System.out.println(realpath);

         //判断文件是否存在
         if(image!=null){
             /*
              * 创建文件虚拟的
              *
              * new File(realpath):文件路径
              *
              * imageFileName:文件名称
              *
              */
             File savefile = new File(new File(realpath), imageFileName);

             if(!savefile.getParentFile().exists())
             {
                 savefile.getParentFile().mkdir();

                 FileUtils.copyFile(image, savefile);
                 ActionContext.getContext().put("message", "文件上传成功");
             }
         }
         return "success";
     }

     /*
      * 上传多个文件
      */
     public String execute1() throws Exception{
         //image
         /*
          *   得到上传文件的真实路径(需要保存的路径)
          */
         String realpath = ServletActionContext.getServletContext().getRealPath("/image");
         System.out.println(realpath);

         //判断文件是否存在
         if(images!=null){
             /*
              * 创建文件虚拟的
              *
              * new File(realpath):文件路径
              *
              * imageFileName:文件名称
              *
              */
             File savedir = new File(realpath);

             if(!savedir.getParentFile().exists())
             {
                 savedir.mkdirs();

                 for(int i=0;i<images.length;i++)
                 {
                     File savefile = new File(savedir,imageFileNames[i]);
                     FileUtils.copyFile(images[i], savefile);
                 }
                 ActionContext.getContext().put("message", "多个文件文件上传成功");
             }
         }
         return "success";
     }
 }

3、对应的上传单个文件的jsp页面为：

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
  </head>

  <body>
    <form action="${pageContext.request.contextPath}/uploadfile/uploadfile" enctype="multipart/form-data" method="post">
        文件：<input type="file" name="image"/>
        <input type="submit" value="上传"/><br>
        文件类型：${imageContentType}
        文件上传状态：${message}
    </form>
  </body>
</html>

4、对应的上传多个文件的jsp页面为：

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
  </head>
  <body>
    <form action="${pageContext.request.contextPath}/uploadfiles/uploadfiles" enctype="multipart/form-data" method="post">
        文件：<input type="file" name="images"/><br>
            <input type="file" name="images"/><br>
            <input type="file" name="images"/>
        <input type="submit" value="上传"/><br>
        文件上传状态：${message}
    </form>
  </body>
</html>

注：项目中用到的一些jar包如下: