In last Struts 2 file upload example, user is allow to select a single file and upload to the server. In this tutorials, you will learn how to allow user to upload multiple files to the server.

1. Action class

In Action class, you can use the List or Array to store the uploaded files.

FileUploadAction.java


package com.mkyong.common.action;

import java.io.File;
import java.util.ArrayList;
import java.util.List;

import com.opensymphony.xwork2.ActionSupport;

public class MultipleFileUploadAction extends ActionSupport{

	private List<File> fileUpload = new ArrayList<File>();
	private List<String> fileUploadContentType = new ArrayList<String>();
	private List<String> fileUploadFileName = new ArrayList<String>();

	public List<File> getFileUpload() {
		return fileUpload;
	}

	public void setFileUpload(List<File> fileUpload) {
		this.fileUpload = fileUpload;
	}

	public List<String> getFileUploadContentType() {
		return fileUploadContentType;
	}

	public void setFileUploadContentType(List<String> fileUploadContentType) {
		this.fileUploadContentType = fileUploadContentType;
	}

	public List<String> getFileUploadFileName() {
		return fileUploadFileName;
	}

	public void setFileUploadFileName(List<String> fileUploadFileName) {
		this.fileUploadFileName = fileUploadFileName;
	}
	
	public String upload() throws Exception{
		
	    for (File file: fileUpload) {
	        System.out.println("File :" + file);
	    }
	    
	    for (String fileName: fileUploadFileName) {
	        System.out.println("Filename : " + fileName);
	    }

	    for (String fileContentType: fileUploadContentType) {
	        System.out.println("File type : " + fileContentType);
	    }
	    
	    return SUCCESS;
		
	}

	public String display() {
		return NONE;
	}
	
}

2. Result Page

Use <s:file> tag to render multiple file upload components, and set the form enctype type to “multipart/form-data”.

fileupload.jsp


<%@ taglib prefix="s" uri="/struts-tags" %>
<html>
<head>
<s:head />
</head>

<body>
<h1>Struts 2 upload multiple files example</h1>

<s:form action="resultAction" namespace="/" 
method="POST" enctype="multipart/form-data">

<s:file label="File 1" name="fileUpload" size="40" />
<s:file label="File 2" name="fileUpload" size="40" />
<s:file label="FIle 2" name="fileUpload" size="40" />

<s:submit value="submit" name="submit" />
	
</s:form>

</body>
</html>

result.jsp


<%@ taglib prefix="s" uri="/struts-tags" %>
<html>

<body>
<h1>Struts 2 upload multiple files example</h1>

<div class="ads-in-post hide_if_width_less_800">
<script async src="//pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script>
<!-- new 728x90 - After2ndH4 -->
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     style="display:inline-block;width:728px;height:90px"
     data-ad-client="ca-pub-2836379775501347"
     data-ad-slot="3642936086"
	 data-ad-region="mkyongregion"></ins>
<script>
(adsbygoogle = window.adsbygoogle || []).push({});
</script>
</div><h2>
   File Name : <s:property value="fileUploadFileName"/> 
</h2> 

<h2>
   Content Type : <s:property value="fileUploadContentType"/> 
</h2> 

<h2>
   File : <s:property value="fileUpload"/> 
</h2> 

</body>
</html>

3. struts.xml

Link it all ~


<?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>

 	<constant name="struts.devMode" value="true" />

	<package name="default" namespace="/" extends="struts-default">
		
	<action name="multipleFileUploadAction" 
	    class="com.mkyong.common.action.MultipleFileUploadAction" 
            method="display">
		<result name="none">pages/multiplefileupload.jsp</result>
	</action>
		
	<action name="resultAction" 
	     class="com.mkyong.common.action.MultipleFileUploadAction" 
             method="upload">
		 <result name="success">pages/result.jsp</result>
	</action>
   </package>
	
</struts>

4. Demo

http://localhost:8080/Struts2Example/multipleFileUploadAction.action

Struts 2 Multiple files upload example
Struts2 Multiple files upload example

Reference

  1. Struts 2 file upload example
  2. Struts 2 file documentation
  3. http://struts.apache.org/2.0.14/docs/file-upload.html
  4. http://struts.apache.org/2.0.14/docs/how-do-we-upload-files.html
  5. http://www.mkyong.com/struts/struts-file-upload-example/