How to cast ArrayList to ....

Hi,
I got an ArrayList and its values are (1,2,3)
List tempList = new ArrayList();
tempList.add("1");
tempList.add("2");
tempList.add("3");
I am wondering how to convert it to an int [] array.
int [] tempInt;
I know that I can do this : tempList.toArray
but I don't know how to cast this to int[] type of array
(note: not integet [] , just int[])
Can anyone help? thanks a lot.

Note: It would be much more efficient to use the wrapper classes for storing primitives in a Vector/ArrayList/LinkedList/... :
tempList.add(new Integer(1));
tempList.add(new Integer(2));
tempList.add(new Integer(3));
(getting the array as an int[] still requires a for-loop)

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How to cast an object in JSF?

I am working on a travel application. A user can have several bookings and a booking can have several components. A component can be either air or hotel. I want to list the user's bookings on the client using JSF datatable.
<h:dataTable var="component" value="#{booking.components}">
Now depending upon the class of component I need to present different information.
My question is how to cast the variable in JSF ?
Thanks

You can use the String value of Object#getClass()#getName() to lookup the classname and evaluate it in the 'rendered' attribute.
Basic example:
package mypackage;
public class Animal {}
package mypackage;
public class Cat extends Animal {}
package mypackage;
public class Dog extends Animal {}
package mypackage;
public class Fish extends Animal {}MyBeanpublic List<Animal> getList() {
    List<Animal> animals = new ArrayList<Animal>();
    animals.add(new Dog());
    animals.add(new Cat());
    animals.add(new Fish());
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}JSF<h:dataTable value="#{myBean.list}" var="item">
    <h:column>
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        <h:outputText value="It's a Fish" rendered="#{item.class.name == 'mypackage.Fish'}" />
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</h:dataTable>As far there is no way to cast objects in JSF.
Edit
If you find it useful, move the classname request to the superclass:
public class Animal {
    public String getType() {
        String className = getClass().getName();
        return className.substring(className.lastIndexOf('.') + 1);
}Which makes life easier without struggling with package names:<h:outputText value="It's a Cat" rendered="#{item.type == 'Cat'}" />
<h:outputText value="It's a Dog" rendered="#{item.type == 'Dog'}" />
<h:outputText value="It's a Fish" rendered="#{item.type == 'Fish'}" />Message was edited by:
BalusC

How to cast an Object into a specific type (Integer/String) at runtime

Problem:
How to cast an Object into a specific type (Integer/String) at runtime, where type is not known at compile time.
Example:
public class TestCode {
     public static Object func1()
Integer i = new Integer(10); //or String str = new String("abc");
Object temp= i; //or Object temp= str;
return temp;
     public static void func2(Integer param1)
          //Performing some stuff
     public static void main(String args[])
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//cast obj into Integer at run time
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Description:
In example, func1() will be called first which will return an object. Returned object refer to an Integer object or an String object. Now at run time, I want to cast this object to the class its referring to (Integer or String).
For e.g., if returned object is referring to Integer then cast that object into Integer and call func2() by passing Integer object.

GDS123 wrote:
Problem:
How to cast an Object into a specific type (Integer/String) at runtime, where type is not known at compile time.
There is only one way to have an object of an unknown type at compile time. That is to create the object's class at runtime using a classloader. Typically a URLClassloader.
Look into
Class.ForName(String)

How to cast vector to vector with out using loop. and how to override "operator =" of vector for this kind of condition.

Hi All How to TypeCast in vector<>... typedef struct ... to class...
//how to cast the vector to vector cast with out using loop
// is there any way?
//================ This is Type Definition for the class of ClsMytype=====================
typedef struct tagClsMytype
CString m_Name;
int m_Index;
double m_Value;
} xClsMytype;
//================ End of Type Definition for the class of ClsMytype=====================
class ClsMytype : public CObject
public:
ClsMytype(); // Constructor
virtual ~ClsMytype(); // Distructor
ClsMytype(const ClsMytype &e);//Copy Constructor
// =========================================
DECLARE_SERIAL(ClsMytype)
virtual void Serialize(CArchive& ar); /// Serialize
ClsMytype& operator=( const ClsMytype &e); //= operator for class
xClsMytype GetType(); // return the typedef struct of an object
ClsMytype& operator=( const xClsMytype &e);// = operator to use typedef struct
ClsMytype* operator->() { return this;};
operator ClsMytype*() { return this; };
//public veriable decleare
public:
CString m_Name;
int m_Index;
double m_Value;
typedef struct tagClsMyTypeCollection
vector <xClsMytype> m_t_Col;
} xClsMyTypeCollection;
class ClsMyTypeCollection : public CObject
public:
ClsMyTypeCollection(); // Constructor
virtual ~ClsMyTypeCollection(); // Distructor
ClsMyTypeCollection(const ClsMyTypeCollection &e);//Copy Constructor
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virtual void Serialize(CArchive& ar);
xClsMyTypeCollection GetType();
ClsMyTypeCollection& operator=( const xClsMyTypeCollection &e);
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ClsMyTypeCollection* operator->() { return this;}; // operator pointer to ->
operator ClsMyTypeCollection*() {return this;};
public:
vector <ClsMytype> m_t_Col;
//private veriable decleare
private:
//===================================================
ClsMytype& ClsMytype::operator=( const xClsMytype &e )
this->m_Name= e.m_Name;
this->m_Index= e.m_Index;
this->m_Value= e.m_Value;
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//==========================Problem for the vector to vector cast
ClsMyTypeCollection& ClsMyTypeCollection::operator=( const xClsMyTypeCollection &e )
this->m_t_Col= (vector<ClsMytype>)e.m_t_Col; // how to cast
return (*this);
Thanks in Advance

Hi Smirt
You could do:
ClsMyTypeCollection* operator->() {
returnthis;};
// operator pointer to ->
operatorClsMyTypeCollection*()
{returnthis;};
public:
vector<ClsMytype>
m_t_Col;//??
The last line with "vector<xClsMytype>
m_t_Col;". It compiles but I doubt that is what you want.
Regards
Chong

HOW TO CAST NVARCHAR2 TO BLOB

Hello
i must stock my data to a nvarchar2 data (unicode) and i must also make full text search on this column, oracle does not support full text search on unicode data, so i have decided to stock my unicode data to a blob clomun, after i can create a full text index and search data.
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What is your database character set? If it's AL32UTF8 you shouldn't really need to use NVARCHAR2 at all - you can store Unicode data in a VARCHAR2 or CLOB column.
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How to cast object type to integer type?

Hi,
Object [] temp;
Int [] value;
How can I assign temp to value? (value = temp?)
In other words how to cast array of type object to array of type integer?
Thanks a lot.

Hi,
Object [] temp;
Int [] value;
How can I assign temp to value? (value = temp?)
In other words how to cast array of type object to
array of type integer?
Thanks a lot.That my friend, is (sometimes) illegal. other times use
value = (Integer[]) temp;
Pray that temp is holding an Integer array so that you dont throw a runtime exception.
I am assuming you know the diff between "int" and "Integer".

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Hi Naresh,
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Hi,
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rset.next();
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rset.close();
int height = imageProxy.getHeight();
int width = imageProxy.getWidth();
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xwindy wrote:
Does anyone knows how to cast a HashMap to HashMap<String, Object>?
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i'm not quite sure how to use ArrayList, i read the api documentation but it would be better if someone could explain it to me
i have a helper method that returns a random number within a given range that picks an index at random but it won't work, here is my code:
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You are calling he method incorrectly. You do not use the variable type declaration when calling a method. Do this
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How to convert arraylist into array

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If you are using generics, I would use this version of toArray:
List < X > list = ...
X[] array = list.toArray(new X[list.size()]);If you are not using generics, that same thing looks like:
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Hql how to cast number to varchar2

Hello.
How to cast number to varchar2(to string)? I'm using hql toplink implementation and (don't know why) functions like cast(... as ...), to_char(...) and str(...) don't work. Please help me.
Kuba :).
Edited by: 854998 on 2011-04-27 03:12

Hello Chris.
First of all I'd like to thank you for answer. :)
1)I can't use native query.
2)What do you mean?
3)I can't upgrade.
I have something like this(it's only simple example, I have more complex query):
getManager().createQuery("SELECT obj FROM " + EntityClass.class.getSimpleName() + " obj "
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I want to cast obj.number to String.
Here: http://docs.jboss.org/hibernate/core/3.3/reference/en/html/queryhql.html#queryhql-expressions expressions like cast is valid.
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I am using JOptionPane.showInputDialog to ask user for a date input. This will be read in as a String. I need to pass it to a variable call date. And when I print date using JOptionPane, it should be shown as whatever the user keyed in in this format: 25/2/09. How do I do it?

By the way, that's not casting. Casting is when you have a variable whose type is at a particular level of detail, and you assign it a different level of detail -- say, casting an int to a long, or a List to an ArrayList.
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How to cast back and use a retrieved Session Bean reference in a servlet?

Please help!
1. I invoke a Session Bean from a servlet :
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2. I store the travelagent reference in the HTTP Session :
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Now, in another servlet, I have to retrieve the reference to the EJB from the HTTPSession.
I then have to use this reference to call a business method in the EJB Session Bean.
I have tried two ways to retrieve the reference and cast it before calling the business method. I get errors in both forms of casting.
The Values you will see below in the code:
EJB Remote Interface : TravelAgent (TravelAgent.java)
Business Method : listItineraries( )
Servlet which calls the above method : ListItinerary.java
Line 46 of ListItinerary.java : ArrayList itineraries = traveler.listItineraries();------------------------------------------------------------------------------------------------------------------
The two ways along with the error I get on the servlet page in the browser are :
(A)
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java.rmi.NoSuchObjectException: CORBA OBJECT_NOT_EXIST 9998 Maybe; nested exception is:
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com.sun.corba.ee.impl.javax.rmi.CORBA.Util.mapSystemException(Util.java:208)
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(B)
TravelAgent traveler =
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java.rmi.ServerException: RemoteException occurred in server thread; nested exception is:
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     source.traveler.servlet.ListItinerary.processRequest(ListItinerary.java:46)
Could someone advice on how to retrieve and cast the EJBObject's reference from the servlet so that I may use it to call the business method?
Thanks!

Thanks guys! It worked.
1.. I should have used the handle. Got to coding without going deep in the concepts.
2.. I dont know if I could have used the EJB Reference directly (instead of the handle).
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Thanks a lot!
Henry

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Actual column
column1 varchar(3) not null
Expected column
column1 varchar(3) null
Mudassar

Shridar I havent defined it but the derived column has been picked up as not null which is strange
CREATE VIEW test
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SELECT
CASE
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END AS
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I have a HashMap with key as a class name and value as the instance of that class. When I do a 'get' on it with the class name as the key, what I get back is a generic java.lang.Object. I want to cast this generic object to the class to which it belongs. But I don't know the class at compile time. It would be available only at runtime. And I need to invoke methods on the instance of this specifc class.
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Thanks all for the prompt replies. I am using
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But a general question (curiosity) specific to your
comment - extraordinarily generic...
I understand there's definitely some overhead of
reflection. So is it advisable to go for interface
instead of reflection?
Thanks.Arguments for interfaces rather than reflection...
Major benefit at run-time:
Invoking a method using reflection takes more than 20 times as long without using a JIT compiler (using the -Xint option of Java 1.3.0 on WinNT)... Unable to tell with the JIT compiler, since the method used for testing was simple enough to inline - which resulted in an unrealistic 100x speed difference.
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Personal and professional recommendation:
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How to cast ArrayList to ....

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