Why the different results?
is controller code
is jsp:useBean code ( .tag file )
I know that an instance generated by the spring is available throughresource.
Thank you for your help.
1) controller
#Controller
#RequestMapping(value="/healthqna")
public class CounselController {
#Resource(name="counselDAO")
private CounselDAO counselDAO;
#RequestMapping(value="/list", method=RequestMethod.GET)
public string list() {
counselService.getList(); // **Working !!**
}
}
Bean
public class HealthQnATodayTAG {
#Resource(name="counselDAO")
private CounselDAO counselDAO;
public HealthQnATodayTAG() {
counselService.getList(); // **Did Not Working !!**
}
}
Your custom Tag is not a Spring managed bean and so resources will never be injected. You need to load the Model attribute in your controller, set it as a model attribute with required scope and then:
[1] pass it as a parameter to your Tag.
<x:myTag list="${list}"/>
or
[2] Have your custom Tag extend javax.servlet.jsp.tagext.TagSupport which will give you a reference to the PageContext and from which you can then get a handle on the Model attribute.
pageContext.getAttribute("list");
Related
In my Header HTML I display a UL/LI Menu where the visiblity of one of the LI items depends on a Service method call.
I tried this:
HomeController
#Controller
public class HomeController {
private static final Logger log = LogManager.getLogger(HomeController.class);
#Autowired
private EtdService etdService;
#GetMapping("/home")
public String home(Model model) throws EtdException {
model.addAttribute("tierTemplate", etdService.getTierTemplate());
// Also tried this explicitly
model.addAttribute("etdService", etdService);
return "home";
}
}
Service Interface (EtdService)
public interface EtdService {
boolean isChangeUserAllowed();
}
Service Implementation (EtdServiceImpl)
#Component
public class EtdServiceImpl implements EtdService {
#Override
public boolean isChangeUserAllowed() {
System.out.println("Got here");
return false;
}
}
HTML:
<li th:if="${#etdService.isChangeUserAllowed()}" class="nav-item dropdown" id="changeUserPanel" role="presentation">
<!-- ... Definition of this LI -- note can't put a new DIV in a UL list ... -->
</li>
Error:
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'etdService' available
at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeanDefinition(DefaultListableBeanFactory.java:772) ~[spring-beans-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getMergedLocalBeanDefinition(AbstractBeanFactory.java:1221) ~[spring-beans-5.1.4.RELEASE.jar:5.1.4.RELEASE]
In addition to the answer by bphilipnyc (set the direct value into the model),
model.addAttribute("isChangeUserAllowed", etdService.isChangeUserAllowed());
If you need to globalize common Model Attributes without re-adding every time, a solution is a #ControllerAdvice class with a #ModelAttribute, e.g.
/**
* This class is used to globalize common Model Attributes without re-adding every time
* The approach is to mark it as #ControllerAdvice to make it apply to every Controller method,
* and implement a #ModelAttribute Model-Adder to append to the model on every Controller method.
*/
// Makes the methods of this class apply to all Controller Request methods
#ControllerAdvice
public class GlobalController {
#Autowired
MyService myService;
#ModelAttribute // A Model Attribute Adder method
public void setGlobalModelAttributes(HttpServletRequest request, Model model) {
model.addAttribute("isChangeUserAllowed", myService.isChangeUserAllowed());
model.addAttribute("currentUserFullName", myService.getCurrentUserFullName());
}
}
Some more examples
https://stackoverflow.com/a/33879102/1005607
https://www.baeldung.com/spring-mvc-and-the-modelattribute-annotation
You are referencing an instance method in Thymeleaf. Here are two options:
1) Reference it by adding the value of the boolean to the model:
#GetMapping("/home")
public String home(Model model) throws EtdException {
//...
model.addAttribute("isChangeUserAllowed", etdService.isChangeUserAllowed());
return "home";
}
And in your HTML: th:if="${isChangeUserAllowed}"
To avoid NPEs, you can alternatively use #bools.isTrue(isChangeUserAllowed) or the appropriate method in the bools utility.
This is the preferred way and the path that the Thymeleaf documentation takes. A clear benefit is that the front-end is now not tied to the service.
2) Reference it statically instead (not recommended):
Error trying call method from view Thymeleaf Spring
Aside: the recommended way is to use constructor injection instead of autowiring.
I am trying to populate an attribute using the #Value annotation in Spring MVC, and it is not getting populated.
I am trying to access the attribute using Struts2 JSP property. my use case looks like that:
public class TransferCreditsAction extends StudentAwareAction {
protected Log logger = LogFactory.getLog(this.getClass());
#Value( "${transfer.credit.url}" )
private String transferCreditUrl;
public void setStates( List<TranslatedValue> states ) {
this.states = states;
}
#Value( "${transfer.credit.url}" )
public String getTransferCreditUrl() {
return transferCreditUrl;
}
}
My property file looks like:
transfer.credit.url
I am accessing this attribute using JSP which looks like:
<s:property value='transferCreditUrl'/>"
I know for a fact that my JSP can access this field, because I tested it when I have this field set for a default value.
However, this field is not getting populated from my property file. I am using Spring 4.1.6
Any help is really appreciated.
Spring can only inject values in its own managed spring beans. That means your TransferCreditsAction should be a spring bean.
There are various ways to declare your TransferCreditsAction class as a spring bean, already answered elsewhere.
You haven't added whats on top of TransferCreditsAction class.
Values will be injected in a Bean Env.
There are many ways of Doing it
Assuming my property file contains
username=Ashish
app.name=Hello
1.
#Service
#PropertySource(value = { "classpath:sample.properties" })
public class PaloAltoSbiClientImpl implements PaloAltoSbiClient {
public static String username;
#Value("${username}")
public void setUrl(String data) {
username = data;
}
...
2.
#Service
public class PaloAltoSbiClientImpl implements PaloAltoSbiClient {
#Value("${username}")
public static String username;
...
3.
#Component
public class TokenHelper {
#Value("${app.name}")
private String APP_NAME;
Just give the properties file reference on top of the class in which you are trying to get.
#PropertySource(value = { "classpath:sample.properties" })
This issue was happening because I was missing <context:annotation-config/> in my applicationContext. Once I added it, it start working with no issues.
I am working on a Spring MVC application and I have the following problem.
I have this RegistrazioneInfo class that contains some information inserted into a form by the user:
public class RegistrazioneInfo {
#NotNull
#Size(min=16, max=16)
private String codiceFiscale;
String gRecaptchaResponse;
public String getCodiceFiscale() {
return codiceFiscale;
}
public void setCodiceFiscale(String codiceFiscale) {
this.codiceFiscale = codiceFiscale;
}
public String getgRecaptchaResponse() {
return gRecaptchaResponse;
}
public void setgRecaptchaResponse(String gRecaptchaResponse) {
this.gRecaptchaResponse = gRecaptchaResponse;
}
}
Then I have this controller class:
#Controller
public class RegistrazioneController extends BaseController {
private RegistrazioneInfo registrazioneInfo;
...............................................
...............................................
...............................................
}
that contains some methods handling request towards some resources.
Ok, my problem is that I want to use an instance of the previous RegistrazioneInfo class as session attribute by the use of the #SessionAttributes Spring annotation as shown here: http://docs.spring.io/spring/docs/3.2.x/spring-framework-reference/html/mvc.html#mvc-ann-sessionattrib
My problem is, in the previous example do something like this:
#SessionAttributes("pet")
public class EditPetForm {
// ...
}
So what exactly is pet? I think that it is something like an id that identify the object that have to be used as a session attribute or something like this. How can I say to put an instance of my RegistrazioneInfo as session attribute?
#SessionAttributes is declared in a Controller Class (#Controller), so on the class level.
Pet is an Bean Object that persist in HttpSession
From the documentation:
This will typically list the names of model attributes which should be transparently stored in the session or some conversational storage, serving as form-backing beans. Declared at the type level, applying to the model attributes that the annotated handler class operates on.
(emphasis is mine)
Also note that, as indicated in the documentation, you should not use that for "non temporary" elements.
I have many controllers in my Spring MVC web application and there is a param mandatoryParam let's say which has to be present in all the requests to the web application.
Now I want to make that param-value available to all the methods in my web-layer and service-layer. How can I handle this scenario effectively?
Currently I am handling it in this way:
... controllerMethod(#RequestParam String mandatoryParam, ...)
and, then passing this param to service layer by calling it's method
#ControllerAdvice("net.myproject.mypackage")
public class MyControllerAdvice {
#ModelAttribute
public void myMethod(#RequestParam String mandatoryParam) {
// Use your mandatoryParam
}
}
myMethod() will be called for every request to any controller in the net.myproject.mypackage package. (Before Spring 4.0, you could not define a package. #ControllerAdvice applied to all controllers).
See the Spring Reference for more details on #ModelAttribute methods.
Thanks Alexey for leading the way.
His solution is:
Add a #ControllerAdvice triggering for all controllers, or selected ones
This #ControllerAdvice has a #PathVariable (for a "/path/{variable}" URL) or a #RequestParam (for a "?variable=..." in URL) to get the ID from the request (worth mentioning both annotations to avoid blind-"copy/past bug", true story ;-) )
This #ControllerAdvice then populates a model attribute with the data fetched from database (for instance)
The controllers with uses #ModelAttribute as method parameters to retrieve the data from the current request's model
I'd like to add a warning and a more complete example:
Warning: see JavaDoc for ModelAttribute.name() if no name is provided to the #ModelAttribute annotation (better to not clutter the code):
The default model attribute name is inferred from the declared
attribute type (i.e. the method parameter type or method return type),
based on the non-qualified class name:
e.g. "orderAddress" for class "mypackage.OrderAddress",
or "orderAddressList" for "List<mypackage.OrderAddress>".
The complete example:
#ControllerAdvice
public class ParentInjector {
#ModelAttribute
public void injectParent(#PathVariable long parentId, Model model) {
model.addAttribute("parentDTO", new ParentDTO(parentId, "A faked parent"));
}
}
#RestController
#RequestMapping("/api/parents/{parentId:[0-9]+}/childs")
public class ChildResource {
#GetMapping("/{childId:[0-9]+}")
public ChildDTO getOne(#ModelAttribute ParentDTO parent, long childId) {
return new ChildDTO(parent, childId, "A faked child");
}
}
To continue about the warning, requests are declaring the parameter "#ModelAttribute ParentDTO parent": the name of the model attribute is not the variable name ("parent"), nor the original "parentId", but the classname with first letter lowerified: "parentDTO", so we have to be careful to use model.addAttribute("parentDTO"...)
Edit: a simpler, less-error-prone, and more complete example:
#Target(ElementType.TYPE)
#Retention(RetentionPolicy.RUNTIME)
#Documented
#RestController
public #interface ProjectDependantRestController {
/**
* The value may indicate a suggestion for a logical component name,
* to be turned into a Spring bean in case of an autodetected component.
*
* #return the suggested component name, if any
*/
String value() default "";
}
#ControllerAdvice(annotations = ParentDependantRestController.class)
public class ParentInjector {
#ModelAttribute
public ParentDTO injectParent(#PathVariable long parentId) {
return new ParentDTO(parentId, "A faked parent");
}
}
#ParentDependantRestController
#RequestMapping("/api/parents/{parentId:[0-9]+}/childs")
public class ChildResource {
#GetMapping("/{childId:[0-9]+}")
public ChildDTO getOne(#ModelAttribute ParentDTO parent, long childId) {
return new ChildDTO(parent, childId, "A faked child");
}
}
I have two controllers in my Application; one is userController, where I have add, delete and update methods; the other one is studentController, where I also have add, delete and update methods.
All the mappings are same in my methods using #RequestMapping annotation in both controllers. I have one confusion: if we are passing the same action from the JSP, then how will the Dispatcher find the corresponding controller? If anybody could describe this using example will be appreciated.
You have to set a #RequestMapping annotation at the class level the value of that annotation will be the prefix of all requests coming to that controller,
for example:
you can have a user controller
#Controller
#RequestMapping("user")
public class UserController {
#RequestMapping("edit")
public ModelAndView edit(#RequestParam(value = "id", required = false) Long id, Map<String, Object> model) {
...
}
}
and a student controller
#Controller
#RequestMapping("student")
public class StudentController {
#RequestMapping("edit")
public ModelAndView edit(#RequestParam(value = "id", required = false) Long id, Map<String, Object> model) {
...
}
}
Both controller have the same method, with same request mapping but you can access them via following uris:
yourserver/user/edit
yourserver/student/edit
hth
We can have any number of controllers, the URL mapping will decide which controller to call..
Please refer here for detailed Spring MVC multiple Controller example