Samuel Learning

<html:form action="upload-submit.do?queryParam=Successful" enctype="multipart/form-data">

    <p>Please enter some text, just to demonstrate the handling of text elements as opposed to file elements: <br />

    <html:text property="theText" errorStyle="background-color: yellow"/></p>

    <p>Please select the file that you would like to upload: <br />

    <html:file property="theFile" errorStyle="background-color: yellow" /></p>

    <p>If you would rather write this file to another file, please check here: <br />

    <html:checkbox property="writeFile" /></p>

    <p>If you checked the box to write to a file, please specify the file path here: <br />

    <html:text property="filePath" errorStyle="background-color: yellow"/></p>

    <p>

    <html:submit />

</p>

</html:form>

<form-beans>

    <form-bean name="uploadForm"

                   type="org.apache.struts.webapp.upload.UploadForm"/>

</form-beans>

publicclass UploadForm extends ValidatorForm {

/**

     *Thevalueofthetexttheuserhassentasformdata

     */

    protected String theText;

    /**

     *Thevalueoftheembeddedquerystringparameter

     */

    protected String queryParam;

    /**

     *Whetherornottowritetoafile

     */

    protectedbooleanwriteFile;

    /**

     *Thefilethattheuserhasuploaded

     */

    protected FormFile theFile;

    /**

     *Thefilepathtowriteto

     */

protected String filePath;

/**

     *Checktomakesuretheclienthasn'texceededthemaximumalloweduploadsizeinsideofthis validatemethod.

     */

    public ActionErrors validate(

        ActionMapping mapping,

        HttpServletRequest request) {

        ActionErrors errors = super.validate(mapping, request);

        //has the maximum length been exceeded?

        Boolean maxLengthExceeded =

            (Boolean) request.getAttribute(

                MultipartRequestHandler.ATTRIBUTE_MAX_LENGTH_EXCEEDED);

        if ((maxLengthExceeded != null) && (maxLengthExceeded.booleanValue())) {

            if (errors == null) {

                errors = new ActionErrors();

            }

            errors.add(

                ActionMessages.GLOBAL_MESSAGE ,

                new ActionMessage("maxLengthExceeded"));

            errors.add(

                ActionMessages.GLOBAL_MESSAGE ,

                new ActionMessage("maxLengthExplanation"));

        }

        return errors;

}

}

<form-validation>

    <formset>

        <form name="uploadForm">

            <field property="theText" depends="required,minlength">

                <arg key="The Text" resource="false" position="0"/>

                <arg name="minlength" key="${var:minlength}" resource="false" position="1"/>

                <var>

                    <var-name>minlength</var-name>

                    <var-value>5</var-value>

                </var>

            </field>

            <field property="filePath" depends="validwhen">

                <arg key="File Path" resource="false" position="0"/>

                <var>

                    <var-name>test</var-name>

                    <var-value>((writeFile == "false") or (*this* != null))</var-value>

                </var>

            </field>

        </form>

    </formset>

</form-validation>

<action path="/upload-submit"

                type="org.apache.struts.webapp.upload.UploadAction"

                name="uploadForm"

                scope="request"

                validate="true"

                input="input">

            <forward name="input" path="/upload.jsp"/>

            <forward name="display" path="/display.jsp"/>

</action>

publicclass UploadAction extends Action

{

    public ActionForward execute(ActionMapping mapping,

                                 ActionForm form,

                                 HttpServletRequest request,

                                 HttpServletResponse response)

        throws Exception {

        if (form instanceof UploadForm) {

            //this line is here for when the input page is upload-utf8.jsp,

            //it sets the correct character encoding for the response

            String encoding = request.getCharacterEncoding();

            if ((encoding != null) && (encoding.equalsIgnoreCase("utf-8")))

            {

                response.setContentType("text/html; charset=utf-8");

            }

            UploadForm theForm = (UploadForm) form;

            //retrieve the text data

            String text = theForm.getTheText();

            //retrieve the query string value

            String queryValue = theForm.getQueryParam();

            //retrieve the file representation

            FormFile file = theForm.getTheFile();

            //retrieve the file name

            String fileName= file.getFileName();

            //retrieve the content type

            String contentType = file.getContentType();

            boolean writeFile = theForm.getWriteFile();

            //retrieve the file size

            String size = (file.getFileSize() + " bytes");

            String data = null;

            try {

                //retrieve the file data

                ByteArrayOutputStream baos = new ByteArrayOutputStream();

                InputStream stream = file.getInputStream();

                if (!writeFile) {

                    //only write files out that are less than 1MB

                    if (file.getFileSize() < (4*1024000)) {

                        byte[] buffer = newbyte[8192];

                        int bytesRead = 0;

                        while ((bytesRead = stream.read(buffer, 0, 8192)) != -1) {

                            baos.write(buffer, 0, bytesRead);

                        }

                        data = new String(baos.toByteArray());

                    }

                    else {

                        data = new String("The file is greater than 4MB, " +

                                " and has not been written to stream." +

                                " File Size: " + file.getFileSize() + " bytes. This is a" +

                                " limitation of this particular web application, hard-coded" +

                                " in org.apache.struts.webapp.upload.UploadAction");

                    }

                }

                else {

                    //write the file to the file specified

                    OutputStream bos = new FileOutputStream(theForm.getFilePath());

                   int bytesRead = 0;

                    byte[] buffer = newbyte[8192];

                    while ((bytesRead = stream.read(buffer, 0, 8192)) != -1) {

                        bos.write(buffer, 0, bytesRead);

                    }

                    bos.close();

                    data = "The file has been written to """ + theForm.getFilePath() + """";

                }

                //close the stream

                stream.close();

            }

            catch (FileNotFoundException fnfe) {

                returnnull;

            }

            catch (IOException ioe) {

                returnnull;

            }

            //place the data into the request for retrieval from display.jsp

            request.setAttribute("text", text);

            request.setAttribute("queryValue", queryValue);

            request.setAttribute("fileName", fileName);

            request.setAttribute("contentType", contentType);

            request.setAttribute("size", size);

            request.setAttribute("data", data);

            //destroy the temporary file created

            file.destroy();

            //return a forward to display.jsp

            return mapping.findForward("display");

        }

        //this shouldn't happen in this example

        returnnull;

    }

}