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Spring, Java, HTML: How can I populate an HTML form with values?

I want to write a part of a website that lets the user alter the data of a pre existing book. For that, I am trying to use a form which works fine. I just can't figure out how to get the form to display data in the editing fields so the user doesn't have to enter everything again but can simply change some details. My HTML code looks like this:
<form method="post" role="form" class="ui form" id="bookForm" th:action="#{/editBook}" th:object="${bookForm}">
<div class="field">
<label for="name">Book</label>
<input id="name" name="name" th:field="*{name}" th:errorclass="fieldError" type="text" required="required"/><br/>
</div>
I include some more code about errors and other things but this is basically where I want the form not only to pass values to my java file but also to take values about the book and display them in the editing fields.
I think I need to pass the book that the user wants to edit into this form but I'm not sure how. I have tried:
<input type="hidden" id="currentBook" name="currentBook" th:value="${currentBook}"/>
right before the "div" statement and then passing the "currentBook" into HTML with
model.addAttribute("currentBook", currentBook);
in my #GetMapping method of that website. I then changed the "input" statement in my field as well to
<input id="name" name="name" th:field="*{name}" th:value="${currentBook.name}" th:errorclass="fieldError" type="text" required="required"/><br/>
currentBook.name will give me the name of that book just not within this context. Does anyone know what I'm doing wrong and how it will work?
Thank you in advance!

Passing Data from JSP to Servlets from HTML page dynamically

I have a JSP page which reads data from HTML and has CSS,Jquery code in it .
Now my webpage in jsp has two text labels and a add button next to them.
User can enter any no of values in the text field.
Now my requirement is that every time user enters the alue in these fields and clicks on add then that data should be passed on to my servlet. Servlet will basically do some validation and return a boolean variable.
Based on the value of this boolean, I shall change the appearance of my text boxes.
This is required to be done for every time user clicks on Add button.
How can I achieve this ?
My HTML code :
<div id="id1" name="id1" style="display: none;">Add a node: </br>
<input type="text" name="ipaddress" id="ipaddress" placeholder="Enter Node IP"> <input type="text" name="port" id="port" placeholder="Enter Node Port">
<input type="button" value="Add" name="addnodebutton" id="addnodebutton"/>
</div>
The value in ipaddress and port shall be passed on to my servlet and depending on return parameter, their appearance should change.
Can anyone enlighten me how this is actually going to work ?
TIA :)

For passing data to and from a servlet, you have options.
Option 1- You can wrap your html in a form tag and set the action/method properties for your servlet/http method like below:
<form method="POST" action="servletname">
<input type="text" name="ipaddress" id="ipaddress" placeholder="Enter Node IP">
<input type="text" name="port" id="port" placeholder="Enter Node Port">
<input type="submit" value="Add" name="addnodebutton" id="addnodebutton"/>
</form>
The submit would send a request with the input to your servlet. You would then need to handle your request parameters in your servlet, set your values/flags in your response object and forward to the user or jsp/html page of your choice.
Option 2- You can make an ajax call from your jsp, process your input and return a response to your page asynchronously. Example below:
A Simple AJAX with JSP example

How to send label parameter from JSP to servlet?

I have a jQuery dialogue box which contains values as checkboxes. On selecting the checkboxes I am storing the selected values into label. Next I have to send these values from label as parameter through form to servlet but I don't know how to complete it.
Here is my code:
<form action="CallTimer" method="GET">
<label class="button2">Set Date: </label>
<input type="text" name="date" id="date" size="4">
<input type="Submit" name="Submit" value="Submit" id="Submit">
<br/>
Select Reporting Level
<label class="button2" style="display:none" id="depart"> Department</label>
</form>
I am retrieving these parameters in my Servlet as:
String reportname=request.getParameter("depart");
System.out.println(reportname);
But it is returning null values. Please help me.
Thanks in advance.

You have to use hidden input field:
<input type="hidden" name="depart" />

You need to understand what gets passed on form submission and what is not. In a nutshell, only values of the input fields get sent to the server. You have several ways to solve your problem:
Write value to a hidden input field
Modify the query string (what gets sent after ? in your GET request) during form submission (using java script):
?...&depart=xxx

How to get form name value in JSP

Is there a way to get the name of the form element itself using JSP? I searched google and did not find any examples which show how to get the name of the form value specified in the JSP file.
For example, I have the below form,
<html>
<form name="register" action="servregister" method="POST"
onsubmit="return validate();">
</form>
</html>
I would like to get the string "register" to a string variable in JSP. Is there a way to do this?

No, a <form> is not submitted with the request. Instead create a hidden input element which holds that information.
<input type="hidden" name="name of form" value="value" />
or possibly the submit element
<input type="submit" name="distinguishing name" value="submit" />
Either of these in a form with be sent as a url-encoded parameter.
There is probably a better solution to what you are trying to do if you explain your goals.
Consider looking into different patterns for achieving your goals.

Possibility to get all form inputs from several layers of panels and forms

Kinda new to wicket and im wondering if its possible to use a AjaxButton in order to get form values from forms within the first form...
For example, using the "ajaxButton" below would it be possible to also get the value of "anothervalue" even though its not in the same form?
<form>
<input type="submit" wicket:id="ajaxButton" />
<input type="text" wicket:id="aValue" />
<panel>
<form>
<input type="text" wicket:id="anothervalue" />
</form>
</panel>
</form>

Wicket supports nested forms. When you submit the outer form, the inner one should also processed (validate params, update models).