error in try catch

[Ankur kothari]

  import java.io.*;
public class FileTester1
{
	public static void main(String args[])
	{
try
{
	String name = null;
File file = new File(name);
System.out.println(file.getName());

}
catch (IOException e)
{
	e.printStackTrace();
}
	}
}  

this gives me a compile error that the try block doesnt throw an ioexception.......i had to remove io from the catch and make it catch(Exception) and then this compiled

but why is this even happening? why does the compiler complain first of all

thanks

[Ankit Garg]

IOException is a checked exception. So if you catch it, the compiler will make sure that its actually thrown in the body of the associated try block.

Now Exception is also a checked exception. But it has an unchecked subclass RuntimeException. So the compiler will not check if Exception is actually thrown in the body of the try block as the try block might throw a RuntimeException which the compiler is not worried about...

[Ankur kothari]

You mean an ioexception is not thrown in the try block....how is that? i mean when will a try block throw ioexceptions?

[Dejan Miler]

Look in Java documentation.
Method getName do not throw any exception.
IOException will be thrown if you modify you code like this

 import java.io.*;
public class FileTester1
{
    public static void main(String args[])
    {   
try
{
    String name = "F:\\Some file"; //write some invalid path like this one 
                                                 //(I dont have F parttion on my Pc) 
                                                 //and then IOException will be trown.
File file = new File(name);
file.createNewFile();
System.out.println(file.getName());

}
catch (IOException e)
{
    e.printStackTrace();
}
    }
}