file upload problem using internet explorer 8

[debraj mallick]

hi ranchers,

i am using struts2 to upload image file, it works in all browsers excepts ie8, the exception i am getting is

[ WARN] [http-8084-8 06:33:31] (CommonsLogger.java:warn:45) Content-Type not allowed: settingspicture "Tulips.jpg" "upload__4e610b3_131fbdeb7d8__8000_00000081.tmp" image/pjpeg
[ WARN] [http-8084-8 06:33:31] (CommonsLogger.java:warn:49) Could not find action or result
No result defined for action com.cloudlabz.service.cpc.web.action.Welcome and result input

in my struts.xml

<action name="uploadingimages" method="uploadingimages" class="com.web.action.Welcome">
            <interceptor-ref name="fileUpload">
                <param name="maximumSize">2097152</param>
                <param name="allowedTypes">image/png,image/gif,image/jpeg,image/jpg</param>
            </interceptor-ref>
            <interceptor-ref name="defaultStack"></interceptor-ref>
            <result name="save" type="redirectAction">view</result>
            <result name="sessionout" type="redirectAction">login</result>
</action>

i didn't understand why i am not able to upload image file in ie8, do i have to put some extra code for browser compatibility
any help would be appreciated.

[Joe Ess]

debraj mallick wrote:hi ranchers,

Content-Type not allowed:  image/pjpeg

                <param name="allowedTypes">image/png,image/gif,image/jpeg,image/jpg</param>

Now do you see the problem?

[debraj mallick]

Content-Type not allowed:  image/pjpeg 

i don't know what is "image/pjpeg".

[Joe Ess]

It's a progressive JPEG. Add it to the list of allowed file types and you should be fine.

[debraj mallick]

it works
thanks a lot.

[Mohana Rao Sv]

That's why don't depend on allowed contentType approach, otherwise you will face cross browser compatibility issues. Do it manually yourself using this class http://download.oracle.com/javase/6/docs/api/javax/activation/MimetypesFileTypeMap.html. The weird problem i faced mentioned allowed types image/jpeg and i'm uploading a jpeg file but the browser is identifying that file as application/oct-stream and not allowing to upload. Never give a chance to decide your file content type and different browsers will identify the file content type differently sometimes.

[Mohana Rao Sv]

Here, identifying the file contentType by using file extension, Let us assume a smart user modified the file extension. Obviously it will give wrong mime type. What we can do more make it more accurate?

Source code from MimeTypesFileTypeMap.java

 /**
     * Return the MIME type based on the specified file name.
     * The MIME type entries are searched as described above under
     * <i>MIME types file search order</i>.
     * If no entry is found, the type "application/octet-stream" is returned.
     *
     * @param filename  the file name
     * @return          the file's MIME type
     */
    public synchronized String getContentType(String filename) {
        int dot_pos = filename.lastIndexOf("."); // period index

        if (dot_pos < 0)
            return defaultType;

        String file_ext = filename.substring(dot_pos + 1);
        if (file_ext.length() == 0)
            return defaultType;

        for (int i = 0; i < DB.length; i++) {
            if (DB[i] == null)
                continue;
            String result = DB[i].getMIMETypeString(file_ext);
            if (result != null)
                return result;
        }
        return defaultType;
    }