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Trying to use an enum as an input working with thymeleaf

A problem occurs when I try to make POST request by an html page using thymeleaf. A controller should receive an input as an enum, but it throws an error:
java.lang.NoSuchMethodException: com.trade_analysis.model.StockSymbol.<init>()
at java.base/java.lang.Class.getConstructor0(Class.java:3427) ~[na:na]"
I don't know what's not ok. I have seen some examples and have tried many things but I can't make it work as it should.
HTML:
<select class="form-item" th:field="${symbol}" required>
<option value="" selected disabled hidden id="default-symbol">Symbol</option>
<option class="dropdown-menu-button" th:each="symbolOption: ${symbols}" th:value="${symbolOption}" th:text="${symbolOption}"></option>
</select>
Java controler:
#GetMapping(value = "/stocks")
#PreAuthorize(value = "isAuthenticated()")
public String getStockPrices(Model model) throws UserNotFoundException {
User user = userService.getUserByUsername(getUsername());
String apiKey = user.getApiKey() == null ? "" : user.getApiKey();
model.addAttribute("apiKey", apiKey);
model.addAttribute("symbol", "");
model.addAttribute("symbols", asList(StockSymbol.values()));
return "stock-prices-preview";
}
#PostMapping(value = "/stocks")
#PreAuthorize(value = "isAuthenticated()")
public String stockPrices(#ModelAttribute String apiKey, #ModelAttribute StockSymbol symbol, Model model) {
model.addAttribute("apiKey", apiKey);
model.addAttribute("symbol", symbol);
model.addAttribute("symbols", asList(StockSymbol.values()));
return "stock-prices-preview";
}
'StockSymbol' enum:
public enum StockSymbol {
GOOGL("GOOGL"),
MSFT("MSFT"),
AMZN("AMZN"),
IBM("IBM"),
CSCO("CSCO"),
AAPL("AAPL");
String sys;
StockSymbol(String sys) {
this.sys = sys;
}
}
First few lines of error (full error is on: https://pastebin.com/kg8RR7G6)
java.lang.NoSuchMethodException: com.trade_analysis.model.StockSymbol.<init>()
at java.base/java.lang.Class.getConstructor0(Class.java:3427) ~[na:na]
at java.base/java.lang.Class.getDeclaredConstructor(Class.java:2631) ~[na:na]
at org.springframework.web.method.annotation.ModelAttributeMethodProcessor.createAttribute(ModelAttributeMethodProcessor.java:216) ~[spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE]

In your POST handler you have this line:
public String stockPrices(#ModelAttribute String apiKey, #ModelAttribute StockSymbol symbol, Model model) {
Remove the #ModelAttribute annotation. Your problem is that Spring tries to instantiate the enum when it runs the controller method.
Use #RequestParam to obtain the incoming POST parameter by name. You might need to specify the parameter name in the annotation if your compiler doesn't use the -parameters switch.

Update row if references is exist, otherwise delete using spring boot

Need guideline -
How to do hard delete when no reference is available and do soft delete when reference is available, this operation should be performed in a single method itself.
E.g.
I have 1 master table and 3 transactional tables and the master reference is available in all 3 transactional tables.
Now while deleting master row - I have to do the following: If master reference is available then update the master table row and if no master ref. is available delete the row.
I tried following so far.
Service Implementation -
public response doHardOrSoftDelete(Employee emp) {
boolean flag = iMasterDao.isDataExist(emp);
if(flag) {
boolean result = iMasterDao.doSoftDelete(emp);
} else {
boolean result = iMasterDao.doHardDelete(emp);
}
}
Second Approach:
As we know that while deleting a record if the reference is available then it throws ConstraintViolationException so simply we can catch it and check that caught exception is of type ConstraintViolationException or not, if yes then call doSoftDelete() method and return the response. So here you don't need to write method or anything to check the references. But I'm not sure whether it is the right approach or not. Just help me with it.
Here is what I tried again -
public Response deleteEmployee(Employee emp) {
Response response = null;
try{
String status= iMasterDao.deleteEmployeeDetails(emp);
if(status.equals("SUCCESS")) {
response = new Response();
response.setStatus("Success");
response.setStatusCode("200");
response.setResult("True");
response.setReason("Record deleted successfully");
return response;
}else {
response = new Response();
response.setStatus("Fail");
response.setStatusCode("200");
response.setResult("False");
}
}catch(Exception e){
response = new Response();
Throwable t =e.getCause();
while ((t != null) && !(t instanceof ConstraintViolationException)) {
t = t.getCause();
}
if(t instanceof ConstraintViolationException){
boolean flag = iMasterDao.setEmployeeIsDeactive(emp);
if(flag) {
response.setStatus("Success");
response.setStatusCode("200");
response.setResult("True");
response.setReason("Record deleted successfully");
}else{
response.setStatus("Fail");
response.setStatusCode("200");
response.setResult("False");
}
}else {
response.setStatus("Fail");
response.setStatusCode("500");
response.setResult("False");
response.setReason("# EXCEPTION : " + e.getMessage());
}
}
return response;
}
Dao Implementation -
public boolean isDataExist(Employee emp) {
boolean flag = false;
List<Object[]> tbl1 = session.createQuery("FROM Table1 where emp_id=:id")
.setParameter("id",emp.getId())
.getResultList();
if(!tbl1.isEmpty() && tbl1.size() > 0) {
flag = true;
}
List<Object[]> tbl2 = session.createQuery("FROM Table2 where emp_id=:id")
.setParameter("id",emp.getId())
.getResultList();
if(!tbl2.isEmpty() && tbl2.size() > 0) {
flag = true;
}
List<Object[]> tbl3 = session.createQuery("FROM Table3 where emp_id=:id")
.setParameter("id",emp.getId())
.getResultList();
if(!tbl3.isEmpty() && tbl3.size() > 0) {
flag = true;
}
return flag;
}
public boolean doSoftDelete(Employee emp) {
empDet = session.get(Employee.class, emp.getId());
empDet .setIsActive("N");
session.update(empDet);
}
public boolean doHardDelete(Employee emp) {
empDet = session.get(Employee.class, emp.getId());
session.delete(empDet);
}
No matter how many transactional tables will be added with master tbl reference, my code should do the operations(soft/hard delete) accordingly.
In my case, every time new transactional tables get added with a master reference I've do the checks, so Simply I want to skip the isDataExist() method and do the deletions accordingly, how can I do it in a better way?
Please help me with the right approach to do the same.

There's a lot of repeated code in the body of isDataExist() method which is both hard to maintain and hard to extend (if you have to add 3 more tables the code will double in size).
On top of that the logic is not optimal as it will go over all tables even if the result from the first one is enough to return true.
Here is a simplified version (please note that I haven't tested the code and there could be errors, but it should be enough to explain the concept):
public boolean isDataExist(Employee emp) {
List<String> tableNames = List.of("Table1", "Table2", "Table3");
for (String tableName : tableNames) {
if (existsInTable(tableName, emp.getId())) {
return true;
}
}
return false;
}
private boolean existsInTable(String tableName, Long employeeId) {
String query = String.format("SELECT count(*) FROM %s WHERE emp_id=:id", tableName);
long count = (long)session
.createQuery(query)
.setParameter("id", employeeId)
.getSingleResult();
return count > 0;
}
isDataExist() contains a list of all table names and iterates over these until the first successful encounter of the required Employee id in which case it returns true. If not found in any table the method returns false.
private boolean existsInTable(String tableName, Long employeeId) is a helper method that does the actual search for employeeId in the specified tableName.
I changed the query to just return the count (0 or more) instead of a the actual entity objects as these are not required and there's no point to fetch them.
EDIT in response to the "Second approach"
Is the Second Approach meeting the requirements?
If so, then it is a "right approach" to the problem. :)
I would refactor the deleteEmployeeDetails method to either return a boolean (if just two possible outcomes are expected) or to return a custom Enum as using a String here doesn't seem appropriate.
There is repeated code in deleteEmployeeDetails and this is never a good thing. You should separate the logic which decides the type of the response from the code that builds it, thus making your code easier to follow, debug and extend when required.
Let me know if you need a code example of the ideas above.
EDIT #2
Here is the sample code as requested.
First we define a Status enum which should be used as return type from MasterDao's methods:
public enum Status {
DELETE_SUCCESS("Success", "200", "True", "Record deleted successfully"),
DELETE_FAIL("Fail", "200", "False", ""),
DEACTIVATE_SUCCESS("Success", "200", "True", "Record deactivated successfully"),
DEACTIVATE_FAIL("Fail", "200", "False", ""),
ERROR("Fail", "500", "False", "");
private String status;
private String statusCode;
private String result;
private String reason;
Status(String status, String statusCode, String result, String reason) {
this.status = status;
this.statusCode = statusCode;
this.result = result;
this.reason = reason;
}
// Getters
}
MasterDao methods changed to return Status instead of String or boolean:
public Status deleteEmployeeDetails(Employee employee) {
return Status.DELETE_SUCCESS; // or Status.DELETE_FAIL
}
public Status deactivateEmployee(Employee employee) {
return Status.DEACTIVATE_SUCCESS; // or Status.DEACTIVATE_FAIL
}
Here is the new deleteEmployee() method:
public Response deleteEmployee(Employee employee) {
Status status;
String reason = null;
try {
status = masterDao.deleteEmployeeDetails(employee);
} catch (Exception e) {
if (isConstraintViolationException(e)) {
status = masterDao.deactivateEmployee(employee);
} else {
status = Status.ERROR;
reason = "# EXCEPTION : " + e.getMessage();
}
}
return buildResponse(status, reason);
}
It uses two simple utility methods (you can make these static or export to utility class as they do not depend on the internal state).
First checks if the root cause of the thrown exception is ConstraintViolationException:
private boolean isConstraintViolationException(Throwable throwable) {
Throwable root = throwable;
while (root != null && !(root instanceof ConstraintViolationException)) {
root = root.getCause();
}
return root != null;
}
And the second one builds the Response out of the Status and a reason:
private Response buildResponse(Status status, String reason) {
Response response = new Response();
response.setStatus(status.getStatus());
response.setStatusCode(status.getStatusCode());
response.setResult(status.getResult());
if (reason != null) {
response.setReason(reason);
} else {
response.setReason(status.getReason());
}
return response;
}
If you do not like to have the Status enum loaded with default Response messages, you could strip it from the extra info:
public enum Status {
DELETE_SUCCESS, DELETE_FAIL, DEACTIVATE_SUCCESS, DEACTIVATE_FAIL, ERROR;
}
And use switch or if-else statements in buildResponse(Status status, String reason) method to build the response based on the Status type.

the map of the model always returns an empty object

Good evening, I have a Spring MVC project on an e-commerce site.
concerning cart management, when I add a product to the cart by clicking the "Ajouter au panier", it adds good, but the problem if I add another product, I show that the second product .
I made "println" and I noticed that "model.asMap (). get (" panier ")" always returns null. what is the problem please?
Here are some screen prints on the console, controller and index.jsp
Controller
#RequestMapping(value = "/ajouterAuPanier")
public String ajouterAuPanier(#RequestParam Long idArticle, #RequestParam int quantite, Model model) {
System.out.println("111111111111111111111111111111111111111111111");
Panier panier = null;
if (model.asMap().get("panier") == null) {
System.out.println("222222222222222222222222222222222222222222222");
panier = new Panier();
System.out.println("333333333333333333333333333333333333333333333");
model.addAttribute("panier", panier);
System.out.println("9999999999999999999999999999999" + panier.getItems().size());
} else System.out.println("555555555555555555555555555555555555555555555");
panier = (Panier) model.asMap().get("panier");
panier.addArticle(metier.getArticle(idArticle), quantite);
model.addAttribute("categories", metier.listCategories());
model.addAttribute("articles", metier.listArticles());
return "index";
}

Apache Tapestry user logged in feature

I am trying to create a login feature for my apache tapestry website, where after logging in, instead of the 'Log In' and 'Register' button, the email of the logged user should be displayed, along with a 'Log Out' button.
Could anyone please tell how should this be implemented the best way?
I can't seem to figure out how should i detect if the user is logged in, in the frontend part, in order to display a different menu options (i am new in tapestry).
Best regards, Marius.

Authentication (of which login is a part) is very application specific. How you define a User (or do you call it a "Customer", for example) is not something the framework does.
Typically, you will have a SessionStateObject representing your User. You can then use something like this in your layout:
<t:if test="user">
<t:logoutLink/>
<p:else>
<t:signInForm/>
</t:if>
Again, components LogoutLink and SignInForm are for you to implement.
The user may be exposed from the Java code as:
#Property
#sessionState(create=false)
private User user;
This says that the user field is linked to a value stored in the HTTP session; further, the User will not be created when the field is first read; instead, your SignInForm component should assign to its user field.

After a little bit of research regarding this matter, i found the following approach:
1) I created an Authenticator interface
public interface Authenticator {
Users getLoggedUser();
boolean isLoggedIn();
void login(String email, String password) throws AuthenticationException;
void logout();
}
2) Also created an AuthenticatorImpl.java class that implements that interface
public class AuthenticatorImpl implements Authenticator {
public static final String AUTH_TOKEN = "authToken";
#Inject
private StartDAO dao;
#Inject
private Request request;
public void login(String email, String password) throws AuthenticationException
{
Users user = dao.findUniqueWithNamedQuery("from Users u where u.Email = '" + email + "' and u.Password = '" + password + "'");
if (user == null) { throw new AuthenticationException("The user doesn't exist"); }
request.getSession(true).setAttribute(AUTH_TOKEN, user);
}
public boolean isLoggedIn()
{
Session session = request.getSession(false);
if (session != null) { return session.getAttribute(AUTH_TOKEN) != null; }
return false;
}
public void logout()
{
Session session = request.getSession(false);
if (session != null)
{
session.setAttribute(AUTH_TOKEN, null);
session.invalidate();
}
}
public Users getLoggedUser()
{
Users user = null;
if (isLoggedIn())
{
user = (Users) request.getSession(true).getAttribute(AUTH_TOKEN);
}
return user;
}
}
3) Created the corresponding binding in the AppModule.java class
public static void bind(ServiceBinder binder)
{
binder.bind(StartDAO.class, StartDAOImpl.class);
binder.bind(Authenticator.class, AuthenticatorImpl.class);
}
4) And on my Layout.java page i used it in the following way
#Property
private Users user;
#Inject
private Authenticator authenticator;
void setupRender()
{
if(authenticator.getLoggedUser().getAccountType().equals("Administrator")){
administrator = authenticator.getLoggedUser();
}
user = authenticator.getLoggedUser();
}
Object onLogout(){
authenticator.logout();
return Login.class;
}
Layout.tml
<t:if test="user">
<span class="navbar-right btn navbar-btn" style="color: white;">
Welcome ${user.Name}! <a t:type="eventLink" t:event="Logout" href="#">(Logout)</a>
</span>
</t:if>
<t:if negate="true" test="user">
<span class="navbar-right">
<t:pagelink page="user/create" class="btn btn-default navbar-btn">Register</t:pagelink>
<t:pagelink page="user/login" class="btn btn-default navbar-btn">Sign in</t:pagelink>
</span>
</t:if>
This worked for me without any problems. Hope that it helps others.
Best regards, Marius.

Struts2 if tag not working

I am writing a login page that when a invalid user tries to login I redirect to the login action with a error parameter equal to 1.
private String username;
private String password;
private int error;
#Override
public String execute()
{
//validate user input
if (username == null || password == null || username.isEmpty() || password.isEmpty())
{
error = 2;
return LOGIN;
}
LoginModel loginModel = new LoginModel(username, password);
HttpBuilder<LoginModel, User> builder = new HttpBuilder<LoginModel, User>(User.class);
builder.setPath("service/user/authenticate");
builder.setModel(loginModel);
IHttpRequest<LoginModel, User> request = builder.buildHttpPost();
User user = request.execute(URL.BASE_LOCAL);
//redirects to login page
if (user == null)
{
error = 1;
return LOGIN;
}
else
{
return SUCCESS;
}
}
//Getters/Setters
If a invalid user trys to login it redirects to localhost:8080/app/login.action?error=1. I am trying to display a error message to user by access the error parameter by using the if tag but its not working the message is not displaying.
<s:if test="error == 1">
<center>
<h4 style="color:red">Username or Password is invalid!!</h4>
</center>
What am I doing wrong?

As far as I'm concerned what you're doing wrong is completely ignoring the framework.
Roughly, IMO this should look more like this:
public class LoginAction extends ActionSupport {
private String username;
private String password;
#Override
public String validate() {
if (isBlank(username) || isBlank(password)) {
addActionError("Username or Password is invalid");
}
User user = loginUser(username, password);
if (user == null) {
addActionError("Invalid login");
}
}
public User loginUser(String username, String password) {
LoginModel loginModel = new LoginModel(username, password);
HttpBuilder<LoginModel, User> builder = new HttpBuilder<LoginModel, User>(User.class);
builder.setPath("service/user/authenticate");
builder.setModel(loginModel);
IHttpRequest<LoginModel, User> request = builder.buildHttpPost();
return request.execute(URL.BASE_LOCAL);
}
}
You would have an "input" result containing the form, and display any action errors present using whatever style you wanted. If it's critical to change the styling based on which type of login error it is you'd have to play a few more games, but that seems excessive.
Unrelated, but I'd move that loginUser code completely out of the action and into a utility/service class, but at least with it wrapped up in a separate method you can mock it more easily. It certainly does not belong in the execute method.

You need to provide the getter and setter of field 'error' to access it from value stack.
public int getError()
{
return error;
}
public void setError(int error)
{
this.error = error;
}
And try to access it in OGNL:
<s:if test="%{#error==1}"></s:if>
Or using JSTL:
<c:if test="${error==1}"></c:if>