Java Reference
In-Depth Information
public Test(int x) throws CException {
// Code goes here
}
// Rest of the code goes here
}
You must handle the
CException
when you create an object of the
Test
class using any of its constructors as
Test t = null;
try {
t = new Test();
}
catch (CException e) {
// Handle exception here
}
If you do not handle the
CException
using a
try-catch
block, you must use a
throws
clause to specify that the
method or constructor that uses the constructor of the
Test
class may throw
CException
.
If an instance initializer throws a checked exception, you must declare a constructor for your class. The compiler
will add a default constructor to your class if you do not add one. However, the compiler will not add a
throws
clause
to the default constructor, which will break the above rule. The following code will not compile:
public class Test123 {
{
// May throw CException, which is a checked exception.
}
}
When the
Test123
class is compiled, the compiler adds a default constructor, and the class
Test123
will look
as follows:
public class Test123 {
{
// May throw CException, which is a checked exception.
}
public Test123() {
// An empty body. The compiler did not add a throws clause.
}
}
Note that the default constructor, which was added by the compiler, does not contain a
throws
clause to include
CException
, which is thrown by the instance initializer. This is the reason that the
Test123
class will not compile. To
make the
Test123
class compile, you must add at least one constructor explicitly and use a
throws
clause to specify
that it may throw
CException
.
