I am passing a list inside a session from servlet to a jsp as follows :
HttpSession session = req.getSession();
session.setAttribute("list1", arrayList);
Inside the JSP I am printing the list as follows :
<form action="Save" method="post">
<c:forEach items="${list1}" var="item">
${item}<br>
<c:set var="stringArray" value="${fn:split(item, ',')}" />
<input type="text" name="Deivice" value="${stringArray[0]}" />
<input type="text" name="DTA" value="${stringArray[1]}" />
<input type="text" name="Type" value="${stringArray[2]}" />
<br>
</c:forEach>
<input type="submit" value="Save">
</form>
Now I want to retrieve the list in a servlet (after the user modifies it in the UI)
How can I pass the values back to the servlet ? Basically, I want to pass a list,alow the user to modify the contents of the list on the UI and want the modified contents of the list in a servlet.
Simply submit the form and get the values in Servelt using request.getParameterMap() or request.getParameterValues(String) that returns String[] for each parameter name that is submitted.
For e.g
String[] devices = request.getParameterValues("Deivice");
Related
I am able to display an ArrayList of beans in a JSP form using JSTL by looping through the list and outputting the bean properties in a HTML input tag.
<c:forEach items="${listOfBeans}" var="bean">
<tr>
<td><input type="text" id="foo" value="${bean.foo}"/></td>
<td><input type="text" id="bar" value="${bean.bar}"/></td>
</tr>
</c:forEach>
How do I code the JSP so that when the page submits then the updated values are in the appropriate item of the the ArrayList?
Given this simplified model:
public class Item {
private Long id;
private String foo;
private String bar;
// ...
}
Here's how you can do it provided ${items} is List<Item>:
<c:forEach items="${items}" var="item">
<tr>
<td>
<input type="hidden" name="id" value="${item.id}" />
<input name="foo_${item.id}" value="${fn:escapeXml(item.foo)}" />
</td>
<td>
<input name="bar_${item.id}" value="${fn:escapeXml(item.bar)}" />
</td>
</tr>
</c:forEach>
(note the importance of fn:escapeXml() as XSS attack prevention)
So, basically, you need to set the item's unique identifier as a hidden input field in each row as shown in above snippet:
<input type="hidden" name="id" value="${item.id}" />
And you should in turn use this id as suffix of name of all input fields in the same row such as:
<input name="foo_${item.id}" ... />
In the servlet, you can collect all values of <input type="hidden" name="id" ...> from all rows by request.getParameterValues(). Just loop over it and then grab the individual inputs by id.
for (String id : request.getParameterValues("id")) {
String foo = request.getParameter("foo_" + id);
String bar = request.getParameter("bar_" + id);
// ...
}
You can also do this all without that id and grab all inputs by name as an array like so name="foo" and request.getParameterValues("foo"), but the ordering of request parameters is not under your control. HTML forms will send it in order, but the enduser can easily manipulate the order.
No need for JavaScript mess here.
See also:
Show JDBC ResultSet in HTML in JSP page using MVC and DAO pattern
ServletRequest.getParameterMap() returns Map<String, String[]> and ServletRequest.getParameter() returns String?
Send an Array with an HTTP Get
<form:form action="approveAccount.html" method="GET">
<input type="submit" value="approvAll"/>
<p>Following Accounts are Pending to approve</p>
<c:forEach items="${accountIdList}" var="val">
<li>${val}</li>
</c:forEach>
</form:form>
val is the value that is fetched from database, I want to add a submit button and want to use this fetched value to do some stuffs, how many value get fetched is dynamically decided, how todo that.. here in this scenario, I am getting account id which admin needs to approv, so by adding textbox, admin can assign the role to the this account and then submit the to the database and this all happen with that clk of button
Suppose, in your service class, you have list of accountIds like this
ArrayList<Integer> accountIdList = new ArrayList<>();
accountIdList.add(1);
accountIdList.add(2);
accountIdList.add(3);
& you have added this list into HTTP Session object for further use like
session.setAttribute("accountIds",accountIdList);
In your JSP, you can then use JSTL for-each loop to create dynamic buttons & textboxes as below
<c:forEach var="ids" items="${session.accountIds}" varStatus="loop">
<input type="text" name="role${loop.index}" />
<input type="submit" value="<c:out value=${ids} />" />
</c:forEach>
I hope this helps.
If I understood your question right, your trying to get multiple ids and it's associated roles when the user click submit button. You can try the following to get them:
JSP:
<form:form action="approveAccount.html" method="GET">
<input type="submit" value="approvAll"/>
<p>Following Accounts are Pending to approve</p>
<c:forEach items="${accountIdList}" var="val">
<input type="text" value="${val}" name="id">
<select name="role">
<option value="admin">Admin</option>
<option value="user">user</option>
</select>
</c:forEach>
</form:form>
Servlet:
String [] txt = request.getParameterValues("id");
String [] role = request.getParameterValues("role");
for (int i = 0; i < txt.length; i++){
System.out.println(txt[i]+" "+role[i]);
}
I am passing an object from page1.jsp using
<form action="teste-altera-mvc.jsp" method="get">
<input type="hidden" value="${contato}" name="contato" />
<input type="submit" value="Alterar" />
</form>
Contato is my object with 4 properties. My problem is how can i get this object in "teste-altera-mvc.jsp" and display its properties using expression language
i have created a java project in eclipse,in this project i have an html form customer.html as shown below
<form>
Name :<input type="text" id="name"/>
Address: <input type="text" id="add"/>
Age:<input type="int" id="age"/>
<input type="submit" onclick="what should i call here in my program"/>
</form>
once the user fills the form and submits it i want to access the form field in java code is it possible.if so how or else is there anyother solution to create an xml file for this form
<input type="submit" onclick="only Javascript function can be called here"/>
if you want to access html form elements at java code you need to submit your form at some controller or another jsp. Like..
<form name="new_employee" method="post" action="../admin/newEmployee.do">
Name :<input type="text" name="employeeName"/>
Address: <input type="text" name="add"/>
Age:<input type="text" name="age"/>
<input type="submit" value="Submit"/>
</form>
form elements can be accessed from generated request by their names like..
request.getParameter("employeeName");
<c:forEach items="${movieList}" var="movie" varStatus="status">
<tr class="<c:if test="${status.count % 2 == 0}">even</c:if>">
<td>${movie.title}</td>
<td>${movie.genre}</td>
<td>${movie.year}</td>
<td>${movie.boxoffice}</td>
<td>
<form:form action=edit.htm>
<input type="hidden" name="edit" value="movie name">
<input type="submit" value="Edit">
</form:form>
<form:form action=delete.htm>
<input type="hidden" name="delete" value="movie name">
<input type="submit" value="Edit">
</form:form>
</tr>
</c:forEach>
This is the section of code I have at the moment. The idea is to display movie data, but also provide buttons to send the user to either a filled form page to edit the data or simply delete the respective data and redirect to the same page. I am just unsure as how to pass along the movie object. I know it is simple, but I can't find the reference I used previously...
Thanks.
U can try this :
put this object in a hidden input
<input type="hidden" id="hidden_object" value="" name="hidden_object"></input>
than you can access the value with the method getParameter()
OR
put this object in your session
in your jsp
<% session.setAttribute("movie", ${movie}); %>
good luck