I have a text box in Jsp where I use Spring tags. I want to show the name of a student but associate the id too. At the moment I can only associate the name:
<form:input id="myexample" path="student" value="{student.name}"/>
What I wanna do is similar to what I can do with a SELECT:
<form:select id="myselect" path="student">
<c:forEach items="${studentList}" var="student">
<form:option value="${student.id}" label="${student.name}"></form:option>
</c:forEach>
</form:select>
I would like to send the ID to the "path" but show the name.
Is it possible?
You will need to associate a hidden field to your userId as follows:
<form:input path="student" value="{student.name}"/>
<form:hidden path="student" value="{student.id}"/>
In the first you show the name of the user, and in the second one you hold the userId
Related
<c:forEach var = "student" items="${result}">
<tr>
<th>${student.name}</th>
<th>Notify</th>
</tr>
</c:forEach>
This is my output.jsp. Notice that I've put a link "Notify" to forward it on display.jsp. But I'm not sure how to display a record of student.name onto my display.jsp 's textbox. Thanks
You have to pass the student name over to the display.jsp (e.g. using a GET parameter).
Modify your link as follows:
<th>Notify</th>
Inside your display.jsp your textbox may look like this:
<input type="text" name="studentName" value="${param['studentName']}" />
I have a table that is dynamically created that has rows of movies.
It has a title column,
a media type column,
a rating column,
and a column that contains a "view" button.
When one of these view buttons is clicked,
I would like to go to a page that contains all the details of that movie by sending the title to the controller so I can query for it in mySql.
The problem is that for all these buttons,
the value is always going to be "view".
So my solution is to make the name of the button different as shown in the code below (this is the raw html generated from the jsp):
<html>
<body>
<form action="someAction">
<table>
<tr>
<th>title</th>
<th>type</th>
<th>rating</th>
</tr>
<tr>
<td>title1</td>
<td>DVD</td>
<td>R</td>
<td><input type="submit" name="mediaType.title1" value="view"></td>
</tr>
<tr>
<td>title2</td>
<td>DVD</td>
<td>R</td>
<td><input type="submit" name="mediaType.title2" value="view"></td>
</tr>
<tr>
<td>title3</td>
<td>BLU-RAY</td>
<td>PG-13</td>
<td><input type="submit" name="mediaType.title3" value="view"></td>
</tr>
</table>
</form>
</body>
</html>
I could then use a parameterMap to figure out which view was pressed.
That is messy and Spring has to have some way of being able to do this.
I thought something like this would work in the controller:
#RequestMapping("someAction", params = "mediaType.{title}=view")
public ModelAndView loadPage(String title) {
// use title to query mysql
// build Model
// return ModelAndView
}
However this doesn't work.
Is there something that I can use in Spring that would be simpler and cleaner like above instead of getting the parameterMap from the request?
If I'm understanding this correctly, you have rows of information organized into a table. You're looping through some kind of collection, which has the side effect of making each input field have similar 'name' attributes. As a result, it's difficult to determine which input fields you really care about. You've then chosen to use the button as an identifier (presumably, because only the one button you actually click on get's added to the request -all the others don't get submitted) to determine which 'row', and subsequent input fields.
I think this might all come down to which 'button' you're using. If you're using a literal input tag (type="submit" or "button") the 'value' attribute is what the user sees as the text on the button -so, you're forced to play shenanigans with the 'name' attribute (presumably by adding an index to the name, splitting the string once you get it out of the request, and using that identifier to get the other parameters out of the request that also have the same identifier appended to their 'name' attribute).
JSP
<input type="submit" name="view${varStatus.index}" value="View" />
HTML Source
<input type="submit" name="view3" value="View">
You should probably use the button tag instead. It allows the text that the user sees to be different than the value that is submitted in the request.
JSP
<button type="submit" name="view" value="${varStatus.index}" >View</button>
HTML Source
<button type="submit" name="view" value="3">View</button>
This gives you the 'identifier' for the row.
How Spring fits into this:
I played with the #RequestMapping and the #RequestParam annotations, and was unable to get Spring to give me the values directly into the controller. But, I was able to do it by writing a custom HandlerMethodArgumentResolver along with a custom annotation.
note: I'm using annotations and java config instead of xml config, AND probably more importantly -this was a quick and dirty example to get it working. adjust it as needed for your situation.
HandlerMethodArgumentResolver
Annotation
Controller method
Instead of putting the table inside one form, you could put multiple forms inside the table, in the TRs:
<tr>
<form action="someAction">
<td>title1<input type='hidden' name='title' value='title1' /></td>
<td>DVD</td>
<td>R</td>
<td><input type="submit" value="view"></td>
</form>
</tr>
Then each title has its own form and you send in the title (always with parameter name of title) from a hidden input.
The solution lies in this statement:
"I have a table that is dynamically created that has rows of movies".
Presumably,
you are looping through a list of movies and generating the table in the jsp file and each row has some unique identifier.
Add a hidden to identify the selected row.
Set the value of the hidden value in an onclick handler from the submit buttons.
Here is some example stuff:
<form ...>
<c:forEach blah var="row">
<tr>
...
<td><input type="submit" value="View" onclick="setSelectedRow('${row.id}')"/></td>
</c:forEach>
<input type="hidden" id="blammy" name="blammy" value=""/>
</form>
<script type="text/javascript">
function setSelectedRow(rowId)
{
... set blammy.value equal to rowId.
}
</script>
// the id is used by JavaScript to find the object in the DOM.
// the name is what appears in the request.
#RequestMapping("someAction")
public ModelAndView loadPage(
#RequestParameter("blammy") final String blammy)
{
...
}
I am using JSTL to populate drop down items, where country is an item having { id, name, code } attributes.
My need is to get name and code for selected country.
for example:
Country{c_id, c_name, c_code} is structure of country bean. when user selects this item I need to retrieve two values c_name, c_code.
What I did yet:
As I know, only one value can be assigned to itemValue either c_name or c_code.
I tried to populate all country and match selected country and then set to another path variable, but this also not working.
My code is as
<form:select path="selectedCountry" id="ddlCountryId">
<c:forEach items="${countries}" var="country">
<option value="${country.countryName}" ${country.countryName == selectedCountry ? 'selected' : ''}>${country.countryName}</option>
</c:forEach>
</form:select>
<input class="login_submit" type="submit" value="Login" id="btnSubmitId">
<!-- Read country code of selected country -->
<c:forEach var="country" items="${countries}">
<c:out value="country"></c:out>
<c:choose>
<c:when test="${country.countryName==loginCreadetials.selectedCountry}">
<input name="countryCode" type="hidden" value="${country.countryCode}"/>
</c:when>
</c:choose>
</c:forEach>
How can I do this?
Set the value of your option tag to a String that you can easily parse, for instance
value="${country.countryName}:${country.countryName}"
In your controller, you can then split the string on the ':' character to retrieve your two values.
I have a question on how to update a particular record in a database using JSTL and java servlets.
Ok to call one record, I use a servlet to run a query to populate a jsp page using this type of format.
ResultSet results = getRecords.executeQuery(); //run database query
Result result = ResultSupport.toResult(results);
request.setAttribute("result", result);
RequestDispatcher rd = request.getRequestDispatcher("/showReport.jsp"); //redirect to this page with query info
rd.forward(request, response);
In the jsp page, I use this format to populate the page.
the row number is the corresponding to the index of the value on how the query is run.
<c:forEach var="row" items="${result.rowsByIndex}">
<form action = "/runthis/servlet?id=${row[0]}" method = "get" >
Employee Name<input type="text" value="<c:out value="${row[2]}"/>" />
Department<select>
<option value="<c:out value="${row[4]}"/>"><c:out value="${row[4]}"/></option></select>
<input type="submit" value="Save">
</form>
</c:forEach>
So for instance, if someone changes the Employee Name, but leaves the Department field alone, or vice versa, how would I go about this?
I think I should be able to kick this form action to a "update servlet", but I would rather not "update" every element in the record if I do not need to.
Also I'm still learning web dev, so if you can think of a better way to prepopulate stuff, via javascript or whatever, I'm willing to try that as well, if it's a possible solution.
Thanks for any help!
i think you need to do something like this:
<c:forEach var="row" items="${result.rowsByIndex}">
<form action="/runthis/servlet" method="post">
<input type="hidden" name="id" value="<c:out value="${row[1]}"/>" />
<input type="hidden" name="EmployeeName_orig" value="<c:out value="${row[2]}"/>" />
Employee Name<input type="text" name="EmployeeName" value="<c:out value="${row[2]}"/>" />
<input type="hidden" name="Department_orig" value="<c:out value="${row[4]}"/>" />
Department
<select id="Department" name="Department">
<option value="<c:out value="${row[4]}"/>"><c:out value="${row[4]}"/></option>
</select>
<input type="submit" value="Save" />
</form>
</c:forEach>
and then, in your update servlet (here called /runthis/servlet) you do some form of update employee and set the name and department where the row is id. note that i send the id in a hidden field, but it could just as well be sent in the url as you mentioned in our discussion above!
about your remark on updating every element in a record:
this can be done in different ways. one way is to load the record from database first, and compare the fields to know what fields to update. but that would require an extra read from the database before the update.
another way (the one i have prepared for in my proposed solution) is to have hidden fields, one for each input in your form. this hidden field holds the original value for its input counterpart. this way you can compare the original value with the new value without having to do a read from the database. on the other hand, you're now transferring the double amount of data over the line for each post request.
I'm working in a very simple and small web application, it is a jsp that handles a shopping cart.
What I do at this point is to iterate through all the products that are stored in the car and add them one by one to the jsp with each iteration.
This is the code that adds a row to the jsp in each iteration:
<tr>
<td>
<input type=text name=Quantity value=<%=quantity%>>
</td>
<td>
<input type=text name=id value=<%=id%>>
</td>
<td>
<input type=submit value="Delete" onclick=<%CustomSubmit(request, id); %>>
</td>
</tr>
As you can see I add to the end of each row a submit type control with a custom method for handling Click events, the use of this control is to remove from the car the respective product.
The problem that I have is that when I click in the delete button of a product, the id that is passed to the CustomSubmit(...) method is not the id of the product that I'm trying to remove but the id of the last product added to the jsp.
So, my question is how can I get the correct id from the item that I'm trying to remove?
The way i use to do it is as follows:
Replace
<input type=submit with a button
<input type="button" value="Delete" onclick="deleteIt('yourid');" />
add the deleteIt javascript function, in the function you fill a hidden input field with the id.
Then submit the page and the correct id gets passed to your page
Little sidenote its always prudent to escape all your Strings
dont use <input type=submit but use <input type="submit"
maybe like
<td>
<input type="text" name="id" value="<%=id%>">
</td>
<td>
<input type="button" value="Delete" onclick="deleteItem('<%=id%>')">
</td>
I assume your cart is a list of objects, each having the attributes id and quantity. So I would expect you code to look something like this (noting Peter's answer about using a 'button'):
<input type="button" value="Delete" onclick="CustomSubmit('<%=cartItem.id%>');"/>
I'm not entirely sure what you are trying to do with the 'request' parameter in your original code but if this is the HTTP request all you will get when you try to write it to the JSP is the result of the request.toString method.