instance block

[payal sharma]

If an instance initializer block does not catch a checked exception that can occur during its execution ,then the exception must be declared in the throw clause of every constructor in the class.
One the other hand it is also written that constructor can not specify exception in the header.
please explain
thanks in advance

[Manfred Leonhardt]

Hi Payal,
Your second statement is wrong (your other hand is incorrect)!
To prove it wrong we can just look at the java.io.* package and see many constructors with exceptions specified. For example, let's look at FileInputStream:
public FileInputStream(File file)
throws FileNotFoundException
Regards,
Manfred.

[Desai Sandeep]

Payal,
That is correct - If the instance initializer is not catching a Checked Exception the Constructor should take care of it, by declaring in the throws clause.
The following code snipplet may be useful

<font size=+0><pre>
public class MyClass {
    int i,j;
    
    public MyClass () throws Exception {
        System.out.println("In the MyClass constructor");
        /*
         * Instance Initializer Block
         */
        {
         i = 100;
         j = 200;  
         throw new Exception("An exception"); 
        } 
    }       
}
</pre></font>

Hope this helps,
Sandeep
SCJP2,OCSD(Oracle JDeveloper), OCED(Oracle Internet Platform)