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: