I have Spring application,I want to set parameter in URL and forward to URL.
For example,I click "Show detail" in index.html.Then go to /employees/show/1111.
ShowController.java get 1111.Now I click "show detail",result is white page error.
And I set break point ShowController.java,break point cannot was not working.
Where I should fix it?
Controller
#Controller
#RequestMapping("/employees/show/{employee.empId}/")
public class ShowController {
#Autowired
EmployeeService empService;
#GetMapping
public String details(#RequestParam("empId") String empId, Model model) {
Employee employee = empService.getEmployeeInfo(Long.parseLong(empId)); // break point at this row
model.addAttribute("employee", employee);
return "view/show";
}
index.html
<body>
<table>
<tr>
<th>Id</th>
<th>Name</th>
<th></th>
</tr>
<tr th:each="employee : ${employees}">
<td th:text="${employee.empId}"></td>
<td th:text="${employee.empName}"></td>
<td><a th:href="#{'/employees/show/' + ${employee.empId}}">Show detail</a></td>
</tr>
</table>
<br>
</body>
show.html
<body>
<div th:text="${employee.empId}"></div>
<div th:text="${employee.empName}"></div>
</body>
This folder structure.
The problem is the url. You are using /employees/show/{employee.empId}/ as a base url. And #GetMappingis not mapped to any url, so it takes the exact url from #RequestMapping("/employees/show/{employee.empId}/").
#RequestParam is to extract query parameters, form parameters, and even files from the request, while #PathVariable is used to tell Spring that part of the URI path is a value you want passed to your method.
So, in your case it seems mixed, you are using #RequestParam instead of #PathVariable.
#Controller
#RequestMapping("/employees/show/{employee:.*}/") //since spring will skip anything after a dot(.)
....
#GetMapping
public String details(#PathVariable("empId") String empId, Model model) {....}
I am having a lot of difficulty with POSTing back a form to the controller, which should contain simply an arraylist of objects that the user may edit.
The form loads up correctly, but when it's posted, it never seems to actually post anything.
Here is my form:
<form action="#" th:action="#{/query/submitQuery}" th:object="${clientList}" method="post">
<table class="table table-bordered table-hover table-striped">
<thead>
<tr>
<th>Select</th>
<th>Client ID</th>
<th>IP Addresss</th>
<th>Description</th>
</tr>
</thead>
<tbody>
<tr th:each="currentClient, stat : ${clientList}">
<td><input type="checkbox" th:checked="${currentClient.selected}" /></td>
<td th:text="${currentClient.getClientID()}" ></td>
<td th:text="${currentClient.getIpAddress()}"></td>
<td th:text="${currentClient.getDescription()}" ></td>
</tr>
</tbody>
</table>
<button type="submit" value="submit" class="btn btn-success">Submit</button>
</form>
Above works fine, it loads up the list correctly. However, when I POST, it returns a empty object (of size 0). I believe this is due to the lack of th:field, but anyway here is controller POST method:
...
private List<ClientWithSelection> allClientsWithSelection = new ArrayList<ClientWithSelection>();
//GET method
...
model.addAttribute("clientList", allClientsWithSelection)
....
//POST method
#RequestMapping(value="/submitQuery", method = RequestMethod.POST)
public String processQuery(#ModelAttribute(value="clientList") ArrayList clientList, Model model){
//clientList== 0 in size
...
}
I have tried adding a th:field but regardless of what I do, it causes an exception.
I've tried:
...
<tr th:each="currentClient, stat : ${clientList}">
<td><input type="checkbox" th:checked="${currentClient.selected}" th:field="*{}" /></td>
<td th th:field="*{currentClient.selected}" ></td>
...
I cannot access currentClient (compile error), I can't even select clientList, it gives me options like get(), add(), clearAll() etc, so it things it should have an array, however, I cannot pass in an array.
I've also tried using something like th:field=${}, this causes runtime exception
I've tried
th:field = "*{clientList[__currentClient.clientID__]}"
but also compile error.
Any ideas?
UPDATE 1:
Tobias suggested that I need to wrap my list in a wraapper. So that's what I did:
ClientWithSelectionWrapper:
public class ClientWithSelectionListWrapper {
private ArrayList<ClientWithSelection> clientList;
public List<ClientWithSelection> getClientList(){
return clientList;
}
public void setClientList(ArrayList<ClientWithSelection> clients){
this.clientList = clients;
}
}
My page:
<form action="#" th:action="#{/query/submitQuery}" th:object="${wrapper}" method="post">
....
<tr th:each="currentClient, stat : ${wrapper.clientList}">
<td th:text="${stat}"></td>
<td>
<input type="checkbox"
th:name="|clientList[${stat.index}]|"
th:value="${currentClient.getClientID()}"
th:checked="${currentClient.selected}" />
</td>
<td th:text="${currentClient.getClientID()}" ></td>
<td th:text="${currentClient.getIpAddress()}"></td>
<td th:text="${currentClient.getDescription()}" ></td>
</tr>
Above loads fine:
Then my controller:
#RequestMapping(value="/submitQuery", method = RequestMethod.POST)
public String processQuery(#ModelAttribute ClientWithSelectionListWrapper wrapper, Model model){
...
}
The page loads correctly, the data is displayed as expected. If I post the form without any selection I get this:
org.springframework.expression.spel.SpelEvaluationException: EL1007E:(pos 0): Property or field 'clientList' cannot be found on null
Not sure why it's complaining
(In the GET Method it has: model.addAttribute("wrapper", wrapper);)
If I then make a selection, i.e. tick the first entry:
There was an unexpected error (type=Bad Request, status=400).
Validation failed for object='clientWithSelectionListWrapper'. Error count: 1
I'm guessing my POST controller is not getting the clientWithSelectionListWrapper. Not sure why, since I have set the wrapper object to be posted back via the th:object="wrapper" in the FORM header.
UPDATE 2:
I've made some progress! Finally the submitted form is being picked up by the POST method in controller. However, all the properties appear to be null, except for whether the item has been ticked or not. I've made various changes, this is how it is looking:
<form action="#" th:action="#{/query/submitQuery}" th:object="${wrapper}" method="post">
....
<tr th:each="currentClient, stat : ${clientList}">
<td th:text="${stat}"></td>
<td>
<input type="checkbox"
th:name="|clientList[${stat.index}]|"
th:value="${currentClient.getClientID()}"
th:checked="${currentClient.selected}"
th:field="*{clientList[__${stat.index}__].selected}">
</td>
<td th:text="${currentClient.getClientID()}"
th:field="*{clientList[__${stat.index}__].clientID}"
th:value="${currentClient.getClientID()}"
></td>
<td th:text="${currentClient.getIpAddress()}"
th:field="*{clientList[__${stat.index}__].ipAddress}"
th:value="${currentClient.getIpAddress()}"
></td>
<td th:text="${currentClient.getDescription()}"
th:field="*{clientList[__${stat.index}__].description}"
th:value="${currentClient.getDescription()}"
></td>
</tr>
I also added a default param-less constructor to my wrapper class and added a bindingResult param to POST method (not sure if needed).
public String processQuery(#ModelAttribute ClientWithSelectionListWrapper wrapper, BindingResult bindingResult, Model model)
So when an object is being posted, this is how it is looking:
Of course, the systemInfo is supposed to be null (at this stage), but the clientID is always 0, and ipAddress/Description always null. The selected boolean is correct though for all properties. I'm sure I've made a mistake on one of the properties somewhere. Back to investigation.
UPDATE 3:
Ok I've managed to fill up all the values correctly! But I had to change my td to include an <input /> which is not what I wanted... Nonetheless, the values are populating correctly, suggesting spring looks for an input tag perhaps for data mapping?
Here is an example of how I changed the clientID table data:
<td>
<input type="text" readonly="readonly"
th:name="|clientList[${stat.index}]|"
th:value="${currentClient.getClientID()}"
th:field="*{clientList[__${stat.index}__].clientID}"
/>
</td>
Now I need to figure out how to display it as plain data, ideally without any presence of an input box...
You need a wrapper object to hold the submited data, like this one:
public class ClientForm {
private ArrayList<String> clientList;
public ArrayList<String> getClientList() {
return clientList;
}
public void setClientList(ArrayList<String> clientList) {
this.clientList = clientList;
}
}
and use it as the #ModelAttribute in your processQuery method:
#RequestMapping(value="/submitQuery", method = RequestMethod.POST)
public String processQuery(#ModelAttribute ClientForm form, Model model){
System.out.println(form.getClientList());
}
Moreover, the input element needs a name and a value. If you directly build the html, then take into account that the name must be clientList[i], where i is the position of the item in the list:
<tr th:each="currentClient, stat : ${clientList}">
<td><input type="checkbox"
th:name="|clientList[${stat.index}]|"
th:value="${currentClient.getClientID()}"
th:checked="${currentClient.selected}" />
</td>
<td th:text="${currentClient.getClientID()}" ></td>
<td th:text="${currentClient.getIpAddress()}"></td>
<td th:text="${currentClient.getDescription()}" ></td>
</tr>
Note that clientList can contain null at
intermediate positions. Per example, if posted data is:
clientList[1] = 'B'
clientList[3] = 'D'
the resulting ArrayList will be: [null, B, null, D]
UPDATE 1:
In my exmple above, ClientForm is a wrapper for List<String>. But in your case ClientWithSelectionListWrapper contains ArrayList<ClientWithSelection>. Therefor clientList[1] should be clientList[1].clientID and so on with the other properties you want to sent back:
<tr th:each="currentClient, stat : ${wrapper.clientList}">
<td><input type="checkbox" th:name="|clientList[${stat.index}].clientID|"
th:value="${currentClient.getClientID()}" th:checked="${currentClient.selected}" /></td>
<td th:text="${currentClient.getClientID()}"></td>
<td th:text="${currentClient.getIpAddress()}"></td>
<td th:text="${currentClient.getDescription()}"></td>
</tr>
I've built a little demo, so you can test it:
Application.java
#SpringBootApplication
public class Application {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
}
ClientWithSelection.java
public class ClientWithSelection {
private Boolean selected;
private String clientID;
private String ipAddress;
private String description;
public ClientWithSelection() {
}
public ClientWithSelection(Boolean selected, String clientID, String ipAddress, String description) {
super();
this.selected = selected;
this.clientID = clientID;
this.ipAddress = ipAddress;
this.description = description;
}
/* Getters and setters ... */
}
ClientWithSelectionListWrapper.java
public class ClientWithSelectionListWrapper {
private ArrayList<ClientWithSelection> clientList;
public ArrayList<ClientWithSelection> getClientList() {
return clientList;
}
public void setClientList(ArrayList<ClientWithSelection> clients) {
this.clientList = clients;
}
}
TestController.java
#Controller
class TestController {
private ArrayList<ClientWithSelection> allClientsWithSelection = new ArrayList<ClientWithSelection>();
public TestController() {
/* Dummy data */
allClientsWithSelection.add(new ClientWithSelection(false, "1", "192.168.0.10", "Client A"));
allClientsWithSelection.add(new ClientWithSelection(false, "2", "192.168.0.11", "Client B"));
allClientsWithSelection.add(new ClientWithSelection(false, "3", "192.168.0.12", "Client C"));
allClientsWithSelection.add(new ClientWithSelection(false, "4", "192.168.0.13", "Client D"));
}
#RequestMapping("/")
String index(Model model) {
ClientWithSelectionListWrapper wrapper = new ClientWithSelectionListWrapper();
wrapper.setClientList(allClientsWithSelection);
model.addAttribute("wrapper", wrapper);
return "test";
}
#RequestMapping(value = "/query/submitQuery", method = RequestMethod.POST)
public String processQuery(#ModelAttribute ClientWithSelectionListWrapper wrapper, Model model) {
System.out.println(wrapper.getClientList() != null ? wrapper.getClientList().size() : "null list");
System.out.println("--");
model.addAttribute("wrapper", wrapper);
return "test";
}
}
test.html
<!DOCTYPE html>
<html>
<head></head>
<body>
<form action="#" th:action="#{/query/submitQuery}" th:object="${wrapper}" method="post">
<table class="table table-bordered table-hover table-striped">
<thead>
<tr>
<th>Select</th>
<th>Client ID</th>
<th>IP Addresss</th>
<th>Description</th>
</tr>
</thead>
<tbody>
<tr th:each="currentClient, stat : ${wrapper.clientList}">
<td><input type="checkbox" th:name="|clientList[${stat.index}].clientID|"
th:value="${currentClient.getClientID()}" th:checked="${currentClient.selected}" /></td>
<td th:text="${currentClient.getClientID()}"></td>
<td th:text="${currentClient.getIpAddress()}"></td>
<td th:text="${currentClient.getDescription()}"></td>
</tr>
</tbody>
</table>
<button type="submit" value="submit" class="btn btn-success">Submit</button>
</form>
</body>
</html>
UPDATE 1.B:
Below is the same example using th:field and sending back all other attributes as hidden values.
<tbody>
<tr th:each="currentClient, stat : *{clientList}">
<td>
<input type="checkbox" th:field="*{clientList[__${stat.index}__].selected}" />
<input type="hidden" th:field="*{clientList[__${stat.index}__].clientID}" />
<input type="hidden" th:field="*{clientList[__${stat.index}__].ipAddress}" />
<input type="hidden" th:field="*{clientList[__${stat.index}__].description}" />
</td>
<td th:text="${currentClient.getClientID()}"></td>
<td th:text="${currentClient.getIpAddress()}"></td>
<td th:text="${currentClient.getDescription()}"></td>
</tr>
</tbody>
When you want to select objects in thymeleaf, you dont actually need to create a wrapper for the purpose of storing a boolean select field. Using dynamic fields as per the thymeleaf guide with syntax th:field="*{rows[__${rowStat.index}__].variety}" is good for when you want to access an already existing set of objects in a collection. Its not really designed for doing selections by using wrapper objects IMO as it creates unnecessary boilerplate code and is sort of a hack.
Consider this simple example, a Person can select Drinks they like. Note: Constructors, Getters and setters are omitted for clarity. Also, these objects are normally stored in a database but I am using in memory arrays to explain the concept.
public class Person {
private Long id;
private List<Drink> drinks;
}
public class Drink {
private Long id;
private String name;
}
Spring controllers
The main thing here is that we are storing the Person in the Model so we can bind it to the form within th:object.
Secondly, the selectableDrinks are the drinks a person can select on the UI.
#GetMapping("/drinks")
public String getDrinks(Model model) {
Person person = new Person(30L);
// ud normally get these from the database.
List<Drink> selectableDrinks = Arrays.asList(
new Drink(1L, "coke"),
new Drink(2L, "fanta"),
new Drink(3L, "sprite")
);
model.addAttribute("person", person);
model.addAttribute("selectableDrinks", selectableDrinks);
return "templates/drinks";
}
#PostMapping("/drinks")
public String postDrinks(#ModelAttribute("person") Person person) {
// person.drinks will contain only the selected drinks
System.out.println(person);
return "templates/drinks";
}
Template code
Pay close attention to the li loop and how selectableDrinks is used to get all possible drinks that can be selected.
The checkbox th:field really expands to person.drinks since th:object is bound to Person and *{drinks} simply is the shortcut to referring to a property on the Person object. You can think of this as just telling spring/thymeleaf that any selected Drinks are going to be put into the ArrayList at location person.drinks.
<!DOCTYPE html>
<html lang="en" xmlns="http://www.w3.org/1999/xhtml"
xmlns:th="http://www.thymeleaf.org"
xmlns:layout="http://www.ultraq.net.nz/thymeleaf/layout" >
<body>
<div class="ui top attached segment">
<div class="ui top attached label">Drink demo</div>
<form class="ui form" th:action="#{/drinks}" method="post" th:object="${person}">
<ul>
<li th:each="drink : ${selectableDrinks}">
<div class="ui checkbox">
<input type="checkbox" th:field="*{drinks}" th:value="${drink.id}">
<label th:text="${drink.name}"></label>
</div>
</li>
</ul>
<div class="field">
<button class="ui button" type="submit">Submit</button>
</div>
</form>
</div>
</body>
</html>
Any way...the secret sauce is using th:value=${drinks.id}. This relies on spring converters. When the form is posted, spring will try recreate a Person and to do this it needs to know how to convert any selected drink.id strings into the actual Drink type. Note: If you did th:value${drinks} the value key in the checkbox html would be the toString() representation of a Drink which is not what you want, hence need to use the id!. If you are following along, all you need to do is create your own converter if one isn't already created.
Without a converter you will receive an error like
Failed to convert property value of type 'java.lang.String' to required type 'java.util.List' for property 'drinks'
You can turn on logging in application.properties to see the errors in detail.
logging.level.org.springframework.web=TRACE
This just means spring doesn't know how to convert a string id representing a drink.id into a Drink. The below is an example of a Converter that fixes this issue. Normally you would inject a repository in get access the database.
#Component
public class DrinkConverter implements Converter<String, Drink> {
#Override
public Drink convert(String id) {
System.out.println("Trying to convert id=" + id + " into a drink");
int parsedId = Integer.parseInt(id);
List<Drink> selectableDrinks = Arrays.asList(
new Drink(1L, "coke"),
new Drink(2L, "fanta"),
new Drink(3L, "sprite")
);
int index = parsedId - 1;
return selectableDrinks.get(index);
}
}
If an entity has a corresponding spring data repository, spring automatically creates the converters and will handle fetching the entity when an id is provided (string id seems to be fine too so spring does some additional conversions there by the looks). This is really cool but can be confusing to understand at first.
I have a list of objects and I want to display the values of those objects in a table using thymeleaf, this is what I have so far:
Here is my controller class that adds my list of objects:
#RequestMapping(value = "/showTableWithValues", method = RequestMethod.GET)
public String showTableWithValues(Model model)
{
//list with Persons
ArrayList<Persons> personsList=
new ArrayList<Persons>();
personsList= this.getListOfPersons();
model.addAttribute("list", personsList);
return "showTableWithValues";
}
This is my .html file where i want to show my values:
<html lang="en"
xmlns="http://www.w3.org/1999/xhtml"
xmlns:th="http://www.thymeleaf.org">
<head>
<title>Home</title>
</head>
<body>
<h1>
Show Values
</h1>
<table class="table table-striped">
<thead>
<tr>
<th>ID</th>
<th>Name</th>
<th>Cost</th>
<th>Mins to prepare</th>
<th>Action</th>
</tr>
</thead>
<tbody>
<tr th:each="persons : ${list}">
</tr>
</tbody>
</table>
</body>
</html>
And my Person.java class:
public class Person {
private String name;
private String last_name;
private String nickname;
.....get,setters and constructor
}
You are missing your <TD> tags providing the template which fields to print where. See the Iteration Basics of the documentation
Add <td> tags under <th> and then use the <td th:text="${persons.ID}"></td> respectively to display the relevant data in the table.
I'm using spring mvc for the first time and I'm trying to display and edit a structure in jsp.
I have a class Snippet, which holds a list of objects of type Sentence:
public class Snippet {
private int id;
private List<Sentence> sentences;
// getters, setters, default constructor
}
public class Sentence {
private int id;
private int scale;
private String text;
// getters, setters, default constructor
}
In my controller I give a new snippet for editing and when user clicks "save" store it to my db, then return another one. Currently the sentences list of the snippet is null:
#RequestMapping("/snippet")
public ModelAndView getSnippet() {
return new ModelAndView("snippet", "snippet", snippetService.getSnippet());
}
#RequestMapping("/save")
public ModelAndView saveSnippet(#ModelAttribute Snippet snippet) {
if(snippet != null && snippet.getSentences() != null && !snippet.getSentences().isEmpty()) {
snippetService.updateSnippet(snippet);
}
return new ModelAndView("snippet", "snippet", snippetService.getSnippet());
}
In my snippet.jsp I'd like to display the snippet sentences with their scale, and on save, pass snippet with sentences and scales to the controller for storage:
<form:form method="post" action="save" modelAttribute="snippet">
...
<c:forEach var="sentence" items="${snippet.sentences}">
<tr>
<td>${sentence.id}</td>
<td>${sentence.text}</td>
<td><input type="range" name="sentence.scale" value="${sentence.scale}"
path="sentence.scale" min="0" max="5" /></td>
</tr>
</c:forEach>
<tr>
<td colspan="4"><input type="submit" value="Save" /></td>
</tr>
I think I have to find the right way to use the path attribute but I can't figure it out.
The JSTL c:forEach tag provides the attribute varStatus, which will expose the loop status to the specified variable. Reference the index of varStatus to obtain the index of the current loop and use that index to specify the index of the collection item you want to bind or display.
<c:forEach var="sentence" items="${snippet.sentences}" varStatus="i">
<tr>
<td>${sentence.id}</td>
<td>${sentence.text}</td>
<td>
<form:input type="range"
name="snippet.sentences[${i.index}].scale"
path="sentences[${i.index}].scale"
min="0" max="5"
/></td>
</tr>
</c:forEach>
I am trying out a sample project using Spring MVC annotated Controllers. All the examples I have found online so far bind the JSP to a particular model and the controller uses #ModelAttribute to retrive the model object in the handler method.
How do I go about passing other parameters (not present in the Model object) from the JSP to Controller? Do I use JavaScript to do this? Also can someone clarify what the HttpServletRequest object should be used for.
Thanks.
Just remove the "path" from the jsp input tag and use HttpServletRequest to retrieve the remaining data.
For example I have a bean like
public class SomeData {
private String name;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
Then in the jsp i will have the additional data fields to be send in normal html tag
<form:form method="post" action="somepage" commandName="somedata">
<table>
<tr>
<td>name</td>
<td><form:input path="name" /></td>
</tr>
<tr>
<td>age</td>
<!--Notice, this is normal html tag, will not be bound to an object -->
<td><input name="age" type="text"/></td>
</tr>
<tr>
<td colspan="2">
<input type="submit" value="send"/>
</td>
</tr>
</table>
</form:form>
Notice, the somedata bean has the name field the age is not. So the age field is added without "path". Without the path attribute the object property wont be bound to this field.
on the Controller i will have to use the HttpServletRequest like,
#RequestMapping("/somepage")
public String someAction(#ModelAttribute("somedata") SomeData data, Map<String, Object> map,
HttpServletRequest request) {
System.out.println("Name=" + data.getName() + " age=" + request.getParameter("age"));
/* do some process and send back the data */
map.put("somedata", data);
map.put("age", request.getParameter("age"));
return "somepage";
}
while accessing the data on the view,
<table>
<tr>
<td>name</td>
<td>${somedata.name}</td>
</tr>
<tr>
<td>age</td>
<td>${age}</td>
</tr>
</table>
somedata is the bean which provides the name property and age is explicitly set attribute by the controller.
If one doesn't want to create another class (bean) though it should be there, then apart from #ModelAttrbute one can also use #RequestParam.
public String someAction(#RequestParam("somedata") String data)
{
------
}