JSF :: Managed Bean Is Not Getting Instantiated Intermittently
Jun 5, 2014
I have a JSF bean which is request scope and corresponding JSF UI page. when user tries to open this page, we are getting exception 'Cannot instantiate user.java class <default constructor>'. This does not come always. It comes very rarely. JSF version is 1.2
1. When we have a view and this uses two or three managed beans and not only one, is this ok? is a good design?
2 If we have two views and both of them only share one functionality (they need to display datatable with clients) , for the second view and for the shared functionality, should I in the managed bean for the second view create the same method that gets the clients or reuse the method in the managed bean created for the first view?
I have a situation to load data while JSF page loads. Also have a filter which populates user information from http request.
I was expecting the filter first to populate the user information and in the managed bean get method to verify the user information and get the data (from database). But in this case i see the managed bean get method is invoked before filter populates user information and i get null pointer exception because the user information is null.
I had to work around to get the user information from FacesContext in the managed bean get method because the user information wasn't available. Is there a way to make sure the filter is invoked first?
In my case my managed bean is View Scoped and it supports a UI page which has multiple forms and each form is submitted as AJAX POST request.
As per the statndard, setting restriction to 5 should create 5 views and after that based on LRU algorithm the oldest views should get deleted if 6th views is created.
Therefore any action on the oldest view will throw the ViewExpiredException and i simply redirect the user to view expired page.
1) When i set the restriction to 5 views, i open 4 tabs with 3 forms each. 2) I submit the 3 forms on first tab everything works fine. 3) As soon as I go to 2nd tab and submit the first form thr, i get view expired exception 4) It seems I am exceeding the number of views I mentioned in web.xml
I want to know :
1) Does every AJAX POST submit itself creates a view ? 2) How I can count the number of views created in a session ? 3)Can i force expiry of a view in JSF 2.0.2 while the session is still alive ? 4) Normally JSF 2.0.2 session cachces the views. Lets assume session is alive the entire day but a view was created in morning at 9:00 AM and is not used again the entire day. Assuming that session doesn't reaches the max number of views it can save in entire day, will the view created in morning expire on its own after certain interval of time ? If not , can we still force its expiry while keeping the session alive ?
I'm using a PrimeFaces UploadedFile xhtml page to select a csv file to read and write using a managed bean (SuperCSVParser.java). The file is read and written to an entity class which then persists the data to a database. The application works fine if I specify a file path on the physical server and select a csv file on that file path. But for the production version I want the user to select ANY file name from ANY directory on their local system.
I know about the FacesContext methods and I've looked at some methods from the java.io File class. Most of these methods are about getting the path from the server, where I want to 'pass' the path String from the client machine to allow the uploaded file to go through. When I try with the below code I get:
java.io.FileNotFoundException: data.csv (The system cannot find the file specified)
I'd like to know what I'm doing as I prefer not to explicitly declare a path in the final app. I'm almost sure that's possible.
I have a requirement where in my primefaces datatable ,the filterMatchMode attribute(like any part of field,whole field) needs to be selected by the user by select menu .
To achieve this i have declared a variable in my viewscoped managed bean as filterCriteria and set the filterMatchMode attribute as filterMatchMode="#{beanName.filterCriteria}".The bean variable is getting set in the managed bean on submit but the filtering is not happening,i am getting empty message.
Also when i remove the keyed in value from filter box the data table is not restored which otherwise must be restored in normal situations. I have used and modified the example code given in primefaces showcase here.The code snippet is as below
<h:form id="tblFrm"> <h:selectOneMenu id="filterOptions" value="#{dtFilterView.filterOption}" required="true" requiredMessage="You must select an option!"> <f:selectItem id="hd1" itemLabel="Select" itemValue="#{null}" />
i want to list files from resources folder like this:
@ManagedBean public class galley implements Serializable { private List<String> list; @PostConstruct public void init() { list = new ArrayList<String>();
[Code] ....
but it give me a null pointer exception on fList .... The directory of resources is :
I read JEE6 doc and confused with : Does container managed entity manager (injected by PersistenceContext annotation) is thread-safe in stateless session bean in multiple-thread env?
See code below, if there are 2 requests to stateless sesion bean in 2 concurrent threads , is it using same Entity Manager Instance or not?
@Stateless(name = "HRFacade", mappedName = "HR_FACES_EJB_JPA-HRFacade-HRFacade") public class HRFacadeBean implements HRFacade, HRFacadeLocal { @Resource SessionContext sessionContext;
I am developing a web application using JSF-2.0 on weblogic 10.3.6. I am using Facelets as VDL. I have 5 different machine. They are different according to their OS and their geographical location. On my first xhtml page server (machine) is decided. Then on next page file upload and rest of processing takes place. My restriction is that SSO configuration can be done on only one machine.
So I am restricted to using xhtml files from only my primary server where SSO configuration is done. But I have to connect to servlets or managed-bean of different machine as requests are machine specific and file needs to be uploaded to those machines for processing. So I cannot use redirectUrl as I need to be only on one machine. Is it possible that xhtml on one server can talk to managed-bean on other server(different machine)?.
But resource.returnString(r); gives a org.apache.jasper.JasperException: java.lang.NullPointerException I started the glassfish server in debug mode and found out that "resource" was null. but @PostConstruct in singleton does print which means singleton bean exists.
Can we call singleton beans with no interface in such a way form a session bean? I actually want to acquire instance of singleton bean when a client invokes method in Client bean...
I'm new to JSP but I've to use it to grab data coming from an external site, pass data to a Bean, write data in a DB and redirect the user to another page. Follow the JSP page.
<%@page import="EJB.getResponse"%> <% long paymentID = Long.parseLong(request.getParameter("paymentid")); String responsecode = "9999"; getResponse g = new getResponse();
[Code] ....
This is the bean:
@ManagedBean @RequestScoped public class getResponse implements Serializable { private Long paymentId; private String result; private String auth;
[Code] ....
On the console I see the prints but I receive the NullPointerException
WARNING: StandardWrapperValve[jsp]: PWC1406: Servlet.service() for servlet jsp threw exception java.lang.NullPointerException at EJB.getResponse.printData(getResponse.java:72) at org.apache.jsp.notify_jsp._jspService(notify_jsp.java from :60) at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:111)
Interfaces are 100 % abstract classes.They cannot be instantiated.Their sole purpose is to be implemented.So why does the following code works just fine while it is attempting to instantiate an interface.
interface TestA { String toString(); } public class Test { public static void main(String[] args) { System.out.println(new TestA() { public String toString() { return "test"; }}); } }
I am being told to (assignment) create a new Bread Object in another class than the original. But after that it is asking for get and set methods. Get and set methods of what? It's parameters?
class Bread { private static String breadType; //private field to hold bread type private static int numberOfCaloriesPerSlice; //private field to hold calories per slice
public static String getBreadType() //get method { return breadType;
I have a Member class and a Player class. Players extends Members. I know that player will have all the methods of Member but I was wondering how I could link a player object directly to a member object.
public class Member(){ String name,surname; public Member(String name, String surname){ this.name = name; this.surname = surname;
[Code] ....
What im looking for is the p1.getName() to return John. Can I do something within the Player class for it to inherit from a Member object...
Let's say I have a Junit4 class FooTest.java and variable token. At some point in class the token gets instantiated.
Java Code:
public class Foo { private String token; @Before public void setUp() { // serious is steps to get the application to a certain state where token can get extracted .... token = extractToken(); } } mh_sh_highlight_all('java');
Now I have another class User.java where I need to use this token. Can I inject this token somehow into that class? There is no relation between Foo and User. I can't use Provider method in the configure file because extraction of the token depends on certain system's state and can't be called anywhere anytime.
I have a primefaces editable datatable with column filtering feature.The datatable has live scrolling feature.The problem that i am facing here is that both filtering and scrolling are happening correctly with Request scoped managed bean but when the scope of the same bean is changed to view scope(javax.faces.bean.ViewScoped) then the filtering happens but on removing the keyed in key word from filter box the table content is not reset to original state and also i am not able to scroll down to next set of records on reaching the end of scrolling.Cell editing feature is working perfectly.
One thing that i observed is ,currently i am querying 5000 odd records to load into datatable.But if the number of records is limited below 5000 scrolling is happening correctly but problem with filtering remains same.I even tested by upgrading to Primefaces 5.1 from 3.Code snippet of xhtml page
I'm wondering if there's a way to build a template for managed beans which could be extended by a constructor instead of re-writing beans for each entity. I can do that quite easily for Dao objects by creating facades and using those facades to create Dao implementations for specific entities. Not sure if the same concept works for managed beans and haven't really come accross any searches.
I wrote the following but I'm not sure how to implement or even if the concept of generics and templating can be applied to managed beans in the same way it can be applied to Dao classes:
public class BeanTemplate<T> { private ListDataModel<T> listModel; @EJB private GenDao dao; private Class<T> entityClass;
[Code] .....
The above assumes there's only one method needed in the bean. I thought of extending like this:
public class EmployeeBean extends BeanTemplate<Employee> { public EmployeeBean() { super(Employee.class); }
// how can the methods be called??
Is the same concept for creating dao templates possible for managed beans?
I'm doing a little game in Java and I would like to insert a background music managed by a JButton. When the button is pressed, the music starts and then, to stop it, the button is pressed again. If you don't press the button to stop the music remains in the loop until the player plays.
I finish reading The EntityManager Interface in JEE tutorial. I know I can use container manager entity manager in EJB, but I want to explore how to use application managed entity manager in EJB.
Can I use application managed entity manager in EJB (container management JTA transaction is used)? Where do I should close entity manager if can?
The following is an example from JEE tutorial, but didn't find where to calose entity manager. and can I create mutiple EntityManagerFactory objects and Entity Manager objects to use them in a JTA transaction?
I have an in-cell editable data table with a viewscoped managed bean.I found that the control never goes to the ajax event method onCellEdit when the scope of the bean is @Viewscoped but it works when the scope is changed to request scope.how to get this feature work with viewscope.Below is my code snippet
I have tried this example ([URL].../) with CarDao extending the BaseDao, it works like a charm.However, from the CarDao class, my NetBeans underlined the class name “CarDao” with the error message “A session bean must not extend another session bean.” But I can compile, deploy and run the application without any problem.
I have also heard that a session bean cannot extend another session bean, but why it works here?
I am using Java EE 6, NetBeans 8.0.1 and WebLogic 12c for this code testing.
I have a managed bean for a form. I map the fields filled in the form with managed bean properties. when I submit the form and click new form , values from the previous form submitted gets displayed in the input fields. I used the scope of the from bean to session. what should be its scope so that values should be destroyed after I submit the form .For every new form ,new bean has to be initialized. On submit I navigate to another bean with session scope.
When i create an application Bean how i can update it from another bean? Lets say application Bean has variable h=1 and i want to update from another bean and make it 2 how i can do it? And how i can access the value of a session bean from another bean?
I am working on eclipse kepler, JSF 2.2 with PrimeFaces 4.0 / Mojarra 2.2 library.
actually there are 2 Problems:
I still get this server message no matter what I do.
(( javax.el.PropertyNotFoundException: /Order.xhtml @28,76 value="#{kk.refugee.id}": Target Unreachable, 'refugee' returned null))
and if I delete the input text puls the hidden, the message keeps pop up for 'material' selectOneMenu. -
I have no chance to examin : ((is this javascript code correct, to copy the value of one component to the other.)) these are my xhtml file and java calsses.
**kk.java** ----------- package khldqr.beans; import javax.faces.bean.ManagedBean; import javax.faces.bean.SessionScoped; @SessionScoped @ManagedBean public class kk {