7.10. Allowing Users to Upload Files
Problem
You need to allow users to upload file content to a web application.
Solution
Create an ActionForm that uses the Struts
FormFile object as a property as shown in Example 7-10.
Example 7-10. ActionForm with FormFile property
package com.oreilly.strutsckbk.ch04;
import org.apache.struts.action.ActionForm;
import org.apache.struts.upload.FormFile;
public class UploadForm extends ActionForm {
private FormFile content;
public FormFile getContent( ) {
return content;
}
public void setContent(FormFile content) {
this.content = content;
}
}Then use the html:file tag on the JSP page
(upload_test.jsp) that contains the form as
shown in Example 7-11. For file uploads, the
enctype attribute of the
html:form tag must be set to
multipart/form-data and the
method attribute set to POST.
Example 7-11. JSP for file upload
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib uri="http://jakarta.apache.org/struts/tags-html" prefix="html" %>
<html>
<head>
<title>Struts Cookbook - Chapter 4 : Upload Test</title>
</head>
<body>
<html:form action="/ProcessUpload"
method="POST"
enctype="multipart/form-data">
<html:file property="content"/>
<html:submit/>
</html:form>
</body>
</html>Tip
The default value for the method attribute of the
html:form tag is POST, so the
attribute isn't required here. In this case,
however, explicitly setting the value reduces the risk of the
method type being changed by another developer.
When the form is processed, ...