Displaying a Graph structure in JSP

Question

Hi there,

I have a table in DB which holds child&parent relationships. Now i am trying to display this info in a jsp as a Graph (a single child can have multiple parents).

May be i need to use recursive calls in jsp. has anyone come across this kind of work?

any examples/pointers ?

Thanks

Answer 1

Could the hierarchy fit some combination of List / Map data structures? I have some hierarchal data that I'm working on showing in JSP, but it is only three or so levels deep. A Map has a key-value set of lists, a list has other lists, etc. Here is some of my JSP code. It uses expression langauge and jstl tags to keep things simpler:

<section id="content" class="body">
    <ol id="posts-list" class="hfeed">
      <c:forEach items="${learningEntries}" var="learningEntry">
           <li>
             <table class="wisiEntry">
                <tr>
                    <td class="pictureCell">
                        <img class="wisiEntry-pic" src="${learningEntry.imagePath}" />
                        <div class="tags">
                            <c:forEach items="${learningEntry.tags}" var="tag">
                                <a class="tag" href="/tags/${tag.name}">${tag.name}</a>
                            </c:forEach>
                        </div>
                    </td>
                    <td class="previousNextCell"
                        <div class="wisiEntry-nextSampleButton">Next</div>
                        <div class="wisiEntry-previousSampleButton">Previous</div>
                        <br />
                        <div class="wisiEntry-addTagButton">Tag</div>
                        <div class="wisiEntry-addCommentButton">Comment</div>
                        <br />
                        <div class="wisiEntry-uploadButton">Upload</div>
                    </td>
                    <td>
                        <!-- ERROR HAPPENS HERE. Samples should not be null -->
                       <c:forEach items="${learningEntry.samples}" var="sample" varStatus = "status">
                             <table class="sampleEntry" ${status.first ? '' : 'style = "display:none"'}>
                                <tr>
                                    <td class="sampleCell">
                                        <p class="description">
                                            ${sample.description}
                                        </p>
                                        ...