I want to make a checklist webpage in jsp page. I am using struts2 tags in my jsp page. I want when my jsp first loaded the check box should automatically populated based on the value which comes from database. And when a user manually check or uncheck the check box something should get stored in the database, so that when another user access the same URL he can see the same state of check box. I don't want to use submit button.
Please help me how to implement it....!!!
Thanks in advance
Create String variables in your Struts2 Action files and also getters and setters. Set these variables in the execute() method (or the method you are using in your action class) with true or false values fetched from the database.
Then you can access them like this
<s:property value="varname"/>
You can set variables in your jsp like this
<s:set var="varname" value="varname"/>
Then check checkboxes like this
<input type="checkbox" <s:if test="#varname == 'true'">checked="checked"</s:if>/>
To set the values back to the database without submitting the form you will have to make an ajax call. Check out JQuery ajax() function. You will have to create a url with the parameters and values that will be mapped onto your corresponding variables in your action class. You can use these values in your action you specified in the url to write them to the database
Related
I have a jsp page having a 'submit' option for input.On clicking it i want to update the value of a table called tbIndividual.What can be the best approach to do it?
On jsp page i have somthing like this :
User Name : <%=rs.getString(2)%>
First Name : <%=rs.getString(4)%>
Last Name : <%=rs.getString(5)%>
Email Id : <%=rs.getString(6)%>
Contact : <%=rs.getString(7)%>
<input type="submit" value="ADD"></input>
And now i want to update the value of status of that particular individual from 'NO' to 'WAIT' state.On click of this submit button.
Is making new servlet for this task a good option or doing the code in jsp a better one ?
If i need to make a new servlet then what will be the code for it on jsp page .?Please help.
If you are trying to learn servlet with this project then you should create a separate servlet where you will perform your business logic (e.g addition of element in Db) and jsp should be kept away from business logic because role of jsp is to render the output not to produce the output.
If this is a project for production purposes, then you should ( IMO you must ) opt some web framework. As framework will reduce your effort, headache and increase productivity.
First of all, there are certain things you need to understand while developing web applications in Java. I have a few recommendations and inputs
Please don't use Scriptlets. Scriptlets are deprecated and they make your code clumsy and the maintainance will be hard. Use JSTL
You need to create a form in your html to have a set of variables to push them to the server on clicking submit button. The form will have an action attribute which contains the URL where the request should be sent
Create a Servlet and map with the action URL and write the doPost method which can receive the form parameters and do the business logic whatever changing the status from NO to WAIT or anything else
Please take a note that you need to have Session variables in order to have the store the data in between requests from the same client. eg browser.
Is making new servlet for this task a good option or doing the code in jsp a better one ?
Writing a new servlet is a good option, than doing the business logic in jsp page. jsp is meant for presentation, just view. They shouldn't be used to perform business logic
If i need to make a new servlet then what will be the code for it on jsp page .?
JSP should just have all the necessary html elements and attributes like form, action attribute etc.. to post the parameters in the request to the action URL. Please note the method attribute of form. You should use HTTP POST method for posting form parameters to the server
Note : Finally, Writing Servlets are also NOT recommended. Instead, you should opt for webframeworks like Spring MVC , Struts etc. Please go through the link to understand about web frameworks answered by #BaluC
Hope this clarifies.
I am analayising the existing project, in one of the JSP page I saw that
String server=request.getParameter("server");
But I am trying to check How I can find where is this server parameter is set
I searched for setParameter("server"), no luck
can any one suggest on this
Main idea, I need to change the values for the values which is set in "server" parameter.
You can look in any of HTML elements, where they may have tag like <input type='text' id='server' name='server' /> like that. I have given example of text box, it can be anything.
And no, there is no such method called request.setParameter()
You can get this attribute from the html/jsp page from where the form is being submitted.
It is set by the HTTP request that was generated by the client side (such as a browser). For example, an HTML form, upon submission, would result in an HTTP request with parameters for each field. A standalone client (non-browser) can set request parameters by merely adding those parameters to the URL itself.
Therefore, first you have to determine what is generating the HTTP request that results in your JSP page being called. Once you find who's generating the request, it will be very easy for you to find how the parameter itself is set.
In your web.xml first check, from which form present in JSP/HTML the request is coming.
In the corresponding action, you will get all the input fields in the form, which will be fetched in the servelet through request.getParameter('')
This parameter is set when any form is submitted. Check the page which calls this servlet. That page will contain a form having field like <input type='text' name='server' />. If not found then check URL query parameter.
EDIT
In web.xml check which URL is being mapped to your servlet.
I have a database setup with hibernate, and I want to call a search on the table in my JSP page. How to I call my java function with the jsp page and store the results, then print them on the jsp page?
Search function (Search by subject)
public Iterable<Layouts> getSelectedLayouts(String subjectName){}
I have the class containing this method in my jsp page as a spring bean
custom:useSpringBean var="layoutManager" bean="LayoutManager"
where LayoutManager is the class
I don't know how to call the method in the jsp page and output the results
I'm using a spring/hibernate to connect to the database, and running my jsp on a local tomcat server
Since it's not clear from your question as to what framework you're using. I will just give you a very general and simple answer but you can use the same idea in any framework you use.
You probably have a button in your jsp page which when clicked will invoke a servlet. Inside the servlet, you will have access to the fields that were submitted via the jsp page. Use the fields to create a search object(DAO) and query the database with it.
When you get results from the database, save it in session scope. So now in your jsp page, you can access the object and display it. You can use jstl to access the fields of the object.
I'm using Struts2 to display the contents of a list of objects on a JSP.
The flow of events is as following:
GetDataAction.java -> fetches values from
the database, fills in the ArrayList
named tableList. On success, the
displayData.jsp is shown.
displayData.jsp -> uses the s:iterate tag to display the values of objects
in the tableList.
The user changes some values in the
displayData.jsp and presses on the
Update button. On the click of
Update button, the
UpdateDataAction.java is called.
Now my problem is; How do I use the same tableList in UpdateDataAction.java to get the modified values?
I tried declaring an ArrayList with the same name 'tableList' (along with getters and setters), in UpdateDataAction.java but it throws a NullPointerException.
Please suggest.
IMO the way you are updating is not a good idea.Either you should link every row to a seperate edit page or use ajax.There are many plugins available to update table values using ajax,If you need i can provide you the links
Back to your way of doing it,i guess you are doing it as follows
<s:form action="UpdateDataActionName">
<s:iterator value="tableList">
<s:textfield name="objectName.propertyName1" value="%(propertyName1)">
<s:textfield name="objectName.propertyName2" value="%(propertyName2)">
<s:textfield name="objectName.propertyName3" value="%(propertyName3)">
</s:iterator>
<s:submit value="Update"/>
</s:form>
Now declare a list in your UpdateDataAction,of type <objectNameoftableListType> i.e. the same object type which the tabeList is representing.The name of the list must be objectName.Try to Iteate and check if you are getting the right values as submitted from the jsp.
I need to get the value that a user has entered in a textbox on a JSP. I used JavaScript to obtain the value, but then I need to access that same variable outside the JavaScript later on in the page.
Here's what I have:
<script type="text/javascript">
var sp;
function setPolicy(){
sp = document.getElementById('policy').value;
if(sp != "")
alert("You entered: " + sp)
else
alert("Would you please enter some text?")
}
</script>
the textbox:
input type="text" id='policy' size="15" tabindex = "1" onblur="setPolicy()"
But I need to access the string entered in this "policy" textbox later on in a scriplet to call a function within my session bean. Is there any way I can pass that variable outside the JavaScript? Or is there another way to do this?
Thanks!
JavaScript execution happens at client side and Scriptlet executes at server side. You are trying to combine the two.
You should submit the form to the same page by passing a param which will have the value entered in the textbox. Your scriptlet should check if the param is present or not. First time coming on this jsp the param will not be present, it will be available only when user enter something in textbox.
May not be the best solution as I don't know the whole context.
I'm not sure you have the lifecycle of a jsp down quite yet. By the time that the javascript is running, all the scriptlets have been evaluated.
By this I mean, one the JSP is rendered, html and javascript are emitted on the response to the browser, and there is no more server to interpret the JSP.
So, you should think of your problem as how do I communicate back to the server, the result of the user action?
Probably by posting a form to an action on the server.
If you are asking how to get hold of text input value in a java session bean, it has nothing to do with your javascript code.
The session bean is server side code. To pass the input value to your session bean, you need to change server side code, a servlet, strut action, webwork action depending on which web framework you use.