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Thymeleaf: th:each for two table rows?

How can I, inside a th:each loop create a group of two rows instead of just one?
I know I can do:
<tr th:each="obj: ${listOfObjects}">
<td>a column with data: ${obj.id}</td>
</tr>
However, I want two <tr> elements to be created, as I would do with JSTL:
<c:forEach items="${listOfObjects}" var="obj">
<tr>
<td>${obj.id}</td>
</tr>
<tr>
<td>${obj.name}</td>
</tr>
</c:forEach>
Is there a way to achieve that with Thymeleaf?

You could use a th:block element for grouping the rows together and repeat them:
<th:block th:each="obj: ${listOfObjects}">
<tr>
<td th:text="${obj.id}"></td>
</tr>
<tr>
<td th:text="${obj.name}"></td>
</tr>
</th:block>
You can read more about th:block here

Is there any way to remove an element from array in jsp?

I want to give my users an ability to remove some items from database. Like this:
I have an array in jsp file:
<c:forEach items="${page.content}" var="row" varStatus="status">
<tr>
<td><input type="checkbox"/></td>
<td>${row.name}</td>
<td>${row.profession}</td>
<td>${row.phone}</td>
<td>${row.city.name}</td>
<td><img src="img/del.png"/></td>
Is there any way to remove an item from array "row" (for example, when I click on the picture del.png)? After that, I will send this array to the controller, to let it know which items I want to remove.

So write a if condition inside foreach tag like this.My idea is to exclude or skip the creation of html if if condition is not satisfied with the value you will specify.
<c:forEach items="${page.content}" var="row" varStatus="status">
<c:if test="${row.value != '<What you want to exclude>'}">
<tr>
<td><input type="checkbox"/></td>
<td>${row.name}</td>
<td>${row.phone}</td>
<td>${row.city.name}</td>
</tr>
</c:if>
</c:forEach>

JSP - loop through table by key value

I have a picture attached with pretty much all the information. To add to it. The table data is stored within a java bean within an ArrayList (Each record is one bean).
I would like my application to be able to recognize that I am in CYCLE_ID n and have all the runs displayed in a table (see Desired Results), and for each CYCLE_ID the same thing.
I am open to making changes in the background java class (not shown), or within the jsp.
<div id="activeQueue">
<h2>Active Modeling Queue for <bean:write name="userBean" property="uid" /> </h2>
<c:forEach items="${activeQueueList}" var="currentQueue">
<p>Queue {<c:out value="${currentQueue.modelQueueID}" />} - <c:out value="${currentQueue.PROJECTION_PROJECT_NME}" /></p>
<table>
<tr>
<th>Type</th>
<th>Start Time </th>
<th>Status</th>
</tr>
<tr>
<td><c:out value="${currentQueue.modelQueueDes}" /></td>
<td><c:out value="${currentQueue.ROW_CREATE_TSP}" /></td>
<td><c:out value="${currentQueue.STATUS_DES}" /></td>
</tr>
</table>
</c:forEach>

First prepare a Map using CYCLE_ID as key and the Queue List as the value. Assuming the bean class is ActiveQueue you can do the following
Map<Integer, ActiveQueue> data = new HashMap<Integer, ActiveQueue>();
for(ActiveQueue queue : activeQueueList) {
if(!data.containsKey(queue.CYCLE_ID)) {
data.put(queue.CYCLE_ID, new ArrayList<ActiveQueue>);
}
data.get(queue.CYCLE_ID).add(queue);
}
Now you can use two nested loops in jsp. The outer loop iterates over the Map data and the inner loop iterates over the corresponding Map.entry values. Like following
<div id="activeQueue">
<h2>Active Modeling Queue for <bean:write name="userBean" property="uid" /></h2>
<c:forEach items="${data}" var="entry">
<p>Queue {<c:out value="${entry.key}" />} - <c:out value="${entry.value[0].PROJECTION_PROJECT_NME}" /></p>
<table>
<tr>
<th>Type</th>
<th>Start Time </th>
<th>Status</th>
</tr>
<c:forEach items=${entry.value} var="currentQueue">
<tr>
<td><c:out value="${currentQueue.modelQueueDes}" /></td>
<td><c:out value="${currentQueue.ROW_CREATE_TSP}" /></td>
<td><c:out value="${currentQueue.STATUS_DES}" /></td>
</tr>
</c:forEach>
</table>
</c:forEach>

Instead of having a List<Run> and iterating on it, you should have a List<Cycle>, where each Cycle contains a List<Run>.
Grouping the original flat list of Runs by Cycle is easy with a Map storing the ID of the cycles as keys, and the corresponding cycle as value:
you iterate over the runs
for each run, you fetch the corresponding cycle by ID in the map. If it's not there yet, you create it and store it in the map
you add the run in the cycle
Ath the end, the keySet() of the map contains all the cycles, and each cycle contains all its runs.
Then use two nested foreach loops in the JSP.

JSTL get serial number in a table

I am using JSTL for each loop for iteration over a list & display that data in a table.
I would like to know how to display the serial number in that table.
<c:forEach items="${item.getApps()}" var="app">
<tr><td>....</td> //need to display serial number here
<td><c:out value="${app.getApp()}"></c:out></td>
</tr></c:forEach>
TIA.

You should use varStatus attribute of that tag which keep track of loop status
<c:forEach items="${item.getApps()}" var="app" varStatus="counter">
<tr><td> ${counter.count}"</td> //need to display serial number here
<td><c:out value="${app.getApp()}"></c:out></td>
</tr></c:forEach>
This should work for you.

Try this, Using varStatus property
<c:forEach items="${item.getApps()}" var="app" varStatus="loop">
<tr><td>${loop.index}</td> //need to display serial number here
<td><c:out value="${app.getApp()}"></c:out></td>
</tr></c:forEach>

This should be work definitly
<c:forEach items="${item.getApps()}" var="app" varStatus="counter">
<tr><td> ${counter.index+1}"</td>
<td><c:out value="${app.getApp()}"></c:out></td>
</tr>
</c:forEach>

Display a datatable using jstl

In my java web application, I have a data table called "sell"
sell(id_sell,id_buyer,id_product,date,final_price,shipping_price,sales_tax)
I have created a jsp page which display some information about the user, such as the products which won at the auction; these products are described by "sell". In this page I have to use jstl library and my idea is to use 'c:forEach' tag to iterate every row of the table.
Here is my code:
<table class="table table-bordered">
<thead>
<tr>
<th>Product</th>
<th>Date</th>
<th>Final Price</th>
<th>Shipping Price</th>
<th>Salex Tax</th>
</tr>
</thead>
<tbody>
<c:forEach var="s" items="${sell}">
<tr>
<td><c:out value="${s.id_product}"/></td>
<td><c:out value="${s.date}"/></td>
<td><c:out value="${s.final_price}"/></td>
<td><c:out value="${s.shipping_price}"/></td>
<td><c:out value="${s.sales_tax}"/></td>
</tr>
</c:forEach>
</tbody>
</table>
But this code shows only an empty table. Where am I doing wrong? Do I have to import something?

From your servlet, load the needed data from your data source, and add it to a scope. Your JSP will then be able to access it through an EL expression. For example, to add data in the request scope:
List<> data = yourDao.list();
request.setAttribute("sell", data);
About your comment on your own question, use the session scope wisely. Good practice is to use the smallest scope possible.