How can I make an attachment page for pdf uploads?

I have an attachment page for post images, so that when I click on the thumbnail (on the front end) it takes the user to the attachment page for that image, how would I do the same for pdf files, so that when I click on the direct link to the pdf on the front end to redirects to the pdf attachment page?

<?php if ( wp_attachment_is_image( $post->id ) ) : $att_image = wp_get_attachment_image_src( $post->id, "full"); ?>
    <center>
    <p class="full-attachment">
        <?php /* <a href="<?php echo wp_get_attachment_url($post->id); ?>" title="<?php the_title(); ?>" rel="attachment"> */ ?>
            <img src="<?php echo $att_image[0];?>" width="<?php echo $att_image[1];?>" height="<?php echo $att_image[2];?>"  class="attachment-full" alt="<?php $post->post_title; ?>" />
        <?php /* </a> */ ?>
    </p>
    </center>
<?php else : ?>
    <a href="<?php echo wp_get_attachment_url($post->ID) ?>" title="<?php echo wp_specialchars( get_the_title($post->ID), 1 ) ?>" rel="attachment">
        <?php echo basename($post->guid) ?>
    </a>
<?php endif; ?> 

This is my theme file’s single.php

<?php $file= get_post_meta( $post->ID, 'teacher-resume-upload' );
 if ( $file) { foreach ( $file as $attachment_id ) { $full_size = wp_get_attachment_url( $attachment_id ); printf( '<a href="%s">download</a>', $full_size); } } ?>