Exception « cast « Java Data Type Q&A

1. Casting objects in Java    stackoverflow.com

I saw a few topics on SO about this but none really answered my question so here it is:

String s = "a string";
Object o = s;
s = String(o);  // EDIT ...

2. Why does this compile?    stackoverflow.com

I was taken aback earlier today when debugging some code to find that something like the following does not throw a compile-time exception:

 public Test () { 

3. Mysterious one time Casting Exception    stackoverflow.com

I am trying to use the PropertyChangeSupport of JComponent class. But when I am executing the following code, Clicking on the menu button first time gives Runtime casting Exception, but then it ...

4. Class Cast Exception    stackoverflow.com

why do i get this exception? Map myHash = null myHash = (HashMap)Collections.synchronizedMap(new HashMap()); If i try to use this hashmap, i get java.lang.ClassCastException

5. Java casting an exception (not class cast exception)    stackoverflow.com

When an exception is caught in java is there a use case for casting the exception to a new type? Or is the standard

    throw new DiffException(e)
The ...

6. Cannot cast from Throwable to MyException    stackoverflow.com

I am catching an Exception and trying to examine the getCause() of it, performing some further actions if the cause is a of type MyException, defined in another library. I am getting ...

7. class cast exception java    stackoverflow.com

interface Foo { 

class Beta implements Foo { 

public class Main extends Beta{
    public static void main(String[] args) {
        Beta x ...

8. Class Cast Exception    coderanch.com

i m using JBoss 4.0.3 and i am getting a class cast exception when i try to look up any thing in the context... e.g. when i say: myQueue = (Queue) ctx.lookup("queue/A") i get a class cast exception. I have included jms.jar in the classpath. Any help will be appreciated.. Thanx in advance.

9. Class cast exception    coderanch.com

Hi Iam now writing the error it generates on the browser java.lang.ClassCastException at jrun____ScipDev____jsp____SeraNews____Quiz12ejsp23._jspService(jrun____ScipDev____jsp____SeraNews____Quiz12ejsp23.java, Compiled Code) at allaire.jrun.jsp.HttpJSPServlet.service(HttpJSPServlet.java, Compiled Code) at allaire.jrun.servlet.JRunSE.service(JRunSE.java, Compiled Code) at allaire.jrun.servlet.JRunSE.runServlet(JRunSE.java, Compiled Code) at allaire.jrun.servlet.JRunNamedDispatcher.forward(JRunNamedDispatcher.java, Compiled Code) at allaire.jrun.jsp.JSPServlet.service(JSPServlet.java, Compiled Code) at allaire.jrun.servlet.JRunSE.service(JRunSE.java, Compiled Code) at allaire.jrun.servlet.JRunSE.runServlet(JRunSE.java, Compiled Code) at allaire.jrun.servlet.JRunRequestDispatcher.forward(JRunRequestDispatcher.java, Compiled Code) at QuizServlet.service(QuizServlet.java, Compiled Code) at javax.servlet.http.HttpServlet.service(HttpServlet.java, Compiled Code) at allaire.jrun.servlet.JRunSE.service(JRunSE.java, Compiled Code) at ...

10. Class cast exception    coderanch.com

Hi Im using tomcat server. but whenver i make some changes in my classes i need to restart the machine or else its giving me ClasscastException. i need to know the reason and how this can be avoided. And also where to put the properties file and .tld files in tomcat. do we need to give the location of these in ...

11. class cast exception    coderanch.com

Hello! Well, in a jsp system I'm getting java.lang.ClassCastException: java.lang.String error when trying to access a page. Its strange because when i visit this page for the first time nothing happens. But if i navigate for while and redirect to "the page", this error occurs. A time this error appeared when i created a session variable two times, with different names.... ...

12. Class Cast Exception    coderanch.com

Hi, I am trying to cast a Collection to a LinkedList.Is that possible? At Compile time I am fine but at runtime my code returns a Class Cast Exception at this line : ****************************************** LinkedList acadList = new LinkedList(); acadList = (LinkedList)acadClassHome.findOpenClasses(); --ClassCastException // findOpenClasses() returns a Collection of objects. ******************************************** The findOpenClasses is actually in an EJB which returns a ...

13. Casting caught Exception to Real Type    coderanch.com

Heh - that's pretty horrid. Though I would point out for Christopher's benefit that if you're trying to extract some sort of String description of an exception, toString() is often a better choice than getMessage() - at least for a "general" catch block that catches something like all Exceptions or all RuntimeExceptions. The toString() method usually gives you the exception class ...

14. Class Cast Exception    coderanch.com

If you load the same class file through two class loaders, Java considers them to be different classes in memory. This might be the problem. Java has a family of ClassLoaders that load the .class files from disk or jars or remote servers or wherever they are. There are a special loaders for starting up an application but by the time ...

15. Class Cast Exception    coderanch.com

Hi, Class A { String city; String state; String Zip; } Class B extends A { int phonenumber; } Class C { public A getClassA(A obj) { // do processing return obj; ----1) } public B getClassB() { B b_obj = new B(); b_obj = (B)getClassA((A)b_obj); } } I am able to compile but during runtime i am getting class cast ...

16. exceptions and type casting confusion    coderanch.com

Hi, i have this problem, when dealing with this Array of Objects.I need to be able to tell whether this object is a type String or is a type Boolean, etc, and throwing an exception when the content of the first column it's not of the type that it says on the second column, the tricky part is that every time ...

17. Casting exception - how to overcome    coderanch.com

It's not really that you can't downcast - it's that you can't turn an object into something it's not by downcasting. That will give you runtime problems. Here's an example:- class CastTest { public static void main (String args[]) { Object myArray[] = new Object[2]; myArray[0] = new Object(); myArray[1] = new String ("Hi"); System.out.println("Attempting first cast"); String myString = (String) ...

18. Help! Class Cast Exception    coderanch.com

19. Exception whith Cast ...it's strange    coderanch.com

Hi everybody... I have a problem when i cast a object of a base class ... as follow : class A {} class B extends A {} class C extends A {} public class Q3ae4 { public static void main(String args[]) { A x = new A(); B y = new B(); C z = new C(); x = y; //line ...

20. When does Class Cast Exception occur?    coderanch.com

class f1 {} public class forex2 { public static void main(String args[]) { Object ob = new Object(); Float f = new Float(9f); if (f instanceof Object) System.out.println("Float is Subclass of Object"); f = (Float)ob; //Explicit cast as Objekt is Base of Float ob = f; //no explicit cast neccessary } }

21. When does Class Cast Exception occur?    coderanch.com

class Star1 { public static void main ( String args [ ] ) { Star1 s = new Star1 ( ) ; Object obj = s ; // ---> line 1 obj.toString ( ) ; // ---> line 2 ((Star1)obj).spin( ); // ---> line 3 } void spin ( ) { System.out.println("spin()"); } }

22. Class Cast Exception    coderanch.com

23. Class Cast Exception    coderanch.com

24. getting a class cast exception    coderanch.com

25. Class Cast Exception Problem    coderanch.com

I am receiving the following error whenever i am trying to cast to some other object [B]org.apache.myfaces.context.servlet.AbstractAttributeMap$EntrySetEntry[/B] at com.soltech.EmployerAdmin.deleteRecord(EmployerAdmin.java:81) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:585) at org.apache.myfaces.el.MethodBindingImpl.invoke(MethodBindingImpl.java:132) at org.apache.myfaces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:61) at javax.faces.component.UICommand.broadcast(UICommand.java:109) at org.ajax4jsf.component.UIDataAdaptor.broadcast(UIDataAdaptor.java:1198) at org.ajax4jsf.component.AjaxViewRoot.processEvents(AjaxViewRoot.java:184) at org.ajax4jsf.component.AjaxViewRoot.broadcastEvents(AjaxViewRoot.java:162) at org.ajax4jsf.component.AjaxViewRoot.processApplication(AjaxViewRoot.java:350) at org.apache.myfaces.lifecycle.InvokeApplicationExecutor.execute(InvokeApplicationExecutor.java:32) at org.apache.myfaces.lifecycle.LifecycleImpl.executePhase(LifecycleImpl.java:95) at org.apache.myfaces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:70) at javax.faces.webapp.FacesServlet.service(FacesServlet.java:139) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.ajax4jsf.webapp.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:141) at org.ajax4jsf.webapp.BaseFilter.doFilter(BaseFilter.java:281) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) at ...

26. [closed] Understanding class casting exceptions    coderanch.com

EDIT: I didn't solve this particular error, but when I "downgraded" my sending functions so that multithreading was not supported, I didn't get any of these errors. That means my multithreading functions don't have enough protection - so this bug trace was part of a larger problem. Thread closed. Hello, I'm having trouble understanding this stack trace and error message in ...

27. Class Cast exception    coderanch.com

Hi, Sorry to have missed that, LinksList is the same method where the code is extracted from, so it is a recursive method It returns linksArrayList, And dont think there is any other way by which this arraylist is getting populated. Also, surprisingly, I am being told that is code is working perfectly fine on one of my colleagues system, Is ...

28. Class Cast exception?    coderanch.com

Hey, I have 2 java project one is main application project, and other is the worker project. I am using xsd as contract.now the common schema(xsd) resides in application project. In the worker project I have the response schema which has the common as include schema. so when I compile both projects, using jaxb first, it creates the java classes for ...

29. down cast only throw exception    coderanch.com

No, you misunderstood something. I advice you to reread the subject. Just think about it logically: Class B extends A. It means that B has everything which A has plus it can have some other methods and fields. So whenever you need an A instance you can use a B instance since it contains everything what is needed for the A ...

30. getting Class cast exception    coderanch.com

import java.util.ArrayList; import java.util.HashSet; import java.util.List; public class BetterProgrammerTask16 { public static int[] removeDuplicates(Integer[] a) { /* Please implement this method to remove all duplicates from the original array. Retain the order of the elements and always retain the first occurrence of the duplicate elements. For example, parameter: {2,1,2,3}, result: {2,1,3} */ List al=new ArrayList(); HashSet set=new HashSet(); for(int i=0;i

32. invalid cast exception    coderanch.com

33. Need Help with Class Cast Exception    java-forums.org

Java Code: package cscie160.hw5; import java.net.MalformedURLException; import java.rmi.Naming; import java.rmi.NotBoundException; import java.rmi.RemoteException; import java.rmi.UnknownHostException; public class Client { public static void main(String[] args) { ATM atm = null; try { ATMFactory factory = (ATMFactory)Naming.lookup("//localhost/atmfactory"); atm = factory.getATM(); } catch (MalformedURLException mue) { mue.printStackTrace(); } catch (NotBoundException nbe) { nbe.printStackTrace(); } catch (UnknownHostException uhe) { uhe.printStackTrace(); } catch (RemoteException re) { re.printStackTrace(); ...

34. Casting a Throw Exception    java-forums.org

public class Driver { public static void main(String[] args) { //MAIN IS FOR TESTING PURPOSES ONLY //object created with new class; example of setting age&name + output results Person me=new Person(); me.setAge(125); me.setName("Robert"); System.out.println(me.getName() + " is currently " + me.getAge() + " years old."); //PRINTING THE OBJECT ITSELF System.out.print(me); } }

35. class cast exceptions    forums.oracle.com

It looks like you have other errors as well, such as trying to use the variable "m" outside of the block it was declared in. But as to your main question, why are you even trying to cast the array? Why not use the original list (the l12 list -- you really do need to improve your variable naming, you know) ...

36. Class cast exception    forums.oracle.com

38. Class cast exception instantiating class    forums.oracle.com

If there are several ClassLoaders and they do not share all their classes. Classes loaded with separate loaders cannot see Class objects from each other and reload binaries. This is usally the case when you are using applications servers and you have several applications that interact together. You can try to specify the problematic classes in the beginning of the CLASSPATH ...

39. Class Cast Exception?    forums.oracle.com

40. Class cast exception.    forums.oracle.com

41. Class Cast Exception    forums.oracle.com

42. class cast exception    forums.oracle.com

43. Weird class cast exception    forums.oracle.com

Looks like a classloader issue. The two classes may have the same fully-qualified name, but if they're loaded by different classloaders, they're completely different classes as far as the runtime is concerned. Where is this code running? You say you're doing something in the main method, right? What's kicking off your Spring bean factory?

44. Class Cast Exception in Portable Remote Object    forums.oracle.com

Hey praveen, Thanks for giving your valuable time to my question. I don't understand what you want to mean. I think I have done it in the right way. The code I have shown is not the complete code. It is just code of file that i have created to check where the error is. Please help me in resolving this ...

45. Class Cast Exception    forums.oracle.com

46. Class cast exception while adding data to Set    forums.oracle.com

Hi, I have the code as given below: import java.util.*; public class Test1{ public static void main(String a[]){ Set s = new TreeSet(); s.add(new Person(20)); s.add(new Person(10)); System.out.println(s); } } class Person{ Person(int i){} } When I compile this code it compiles successfully, but while running this I get the exception "java.lang.ClassCastException". Can somebody tell me why is this exception coming. ...

47. A curious casting exception...    forums.oracle.com

Okay...well, why are you putting all those different things in one Vector? How will you differentiate among which is which? Seems (from a preliminary, outside perspective) like it would be better to have a separate data structure for each data type, or a single encapsulating Object to contain the String/Integer/Boolean data, then make a Vector of that Object. But I digress... ...

48. Class Cast Exception    forums.oracle.com

Thanks a lot to everyone for their help and input. Spoon_ I tried what you suggested and it worked. I see now how the newInstance method works and what the earlier poster was saying about passing in the class type. Oh by the way, I used the method for the older versions, I'm not sure if my professor is using java ...

49. class cast exception    forums.oracle.com

Hi im a bit confused at what a classCastException is and what it has to do with this code could any one explane and help if possable thanks foundRooms = checkRooms(roomNum,floorNum); private int checkRooms(int roomNum,int floorNum) { int coin = 0; // i use coin as yes/no Iterator iter = h.getFloorIterator(floorNum); // h means hotel class while (iter.hasNext() == true) { ...

50. Strange class cast exception    forums.oracle.com

51. class cast exception    forums.oracle.com

hi all, here i am getting some problem. here i am trying 2 get the list from database. if i code like this i am getting class cast exception. what should i do to prevent calss cast exception can any body show me some way. public List getEventDetails(MasterVO mastervo)throws SMException, SQLException { MasterVO masterVO = new MasterVO(); List eventDetailList= (List) new ...

52. Class Cast Exception.    forums.oracle.com

53. Class Cast exception    forums.oracle.com

54. Class cast Exception    forums.oracle.com

First investigate. In stead of doing the cast directly, catch the return value in a variable of type Object (assuming it is Object) and investigate what type that object actually is through debugging, System.out, whatever. With that information in hand it might be easier to reason where you are making a mistake and what type of mistake you are making.