about Constructor signature declared to be throws Exception

[Pratap koritala]

How can a construcor declared that it throws Exception,wat is the use of the declaration, the block that uses constructor must be enclosed in "TRY" or not. and wat about the inherited class construtor(the Question is some what ambiguous)

  
class parent
{
   parent(int x) throws IOException
   {
   }              [B]who cares about this exception[/B]
}
class child extends parent 
{
   child() [B]wat must be declared here[/B]
   {
       try
     {
      super(6); [B]if it is enclosed in try block,wat about the rule of "super must be first statement"[/B]   
      }
      catch(Exception e){}
   }
}

[Joe Harry]

Yes you are right. super must be the first statement in a subclass constructor. In the above situation you can just say that the constructor in the subclass also throws the same exception.

[Satish Kota]

Originally posted by ramya sri:
How can a construcor declared that it throws Exception,wat is the use of the declaration, the block that uses constructor must be enclosed in "TRY" or not. and wat about the inherited class construtor(the Question is some what ambiguous)

  
class parent
{
   parent(int x) throws IOException
   {
   }              [B]who cares about this exception[/B]
}
class child extends parent 
{
   child() [B]wat must be declared here[/B]
   {
       try
     {
      super(6); [B]if it is enclosed in try block,wat about the rule of "super must be first statement"[/B]   
      }
      catch(Exception e){}
   }
}

super() must be the 1st statement. Hence the only way a subclass constructor handles the exception is by declaring that it throws it, in such case the method which instantiates this class must handle or declare exception. See this example:

import java.io.*;
class Parent
{
  Parent() throws IOException
  { }
}
 
class Child extends Parent
{
  Child() throws IOException
  {
 
  }
 
  public static void main(String[] args) throws IOException
  {
     new Child();
  }
}