Unable to throw Exception, why?

Question

Within the first catch block why we can't throw an Exception object? Here RuntimeException is working fine.

public class CirEx {
    public Circle getCircle(int id) {
        Connection conn = null;
        try {
            Class.forName("");
            conn = DriverManager.getConnection("");
            PreparedStatement pstmt = conn.prepareStatement("");

            Circle circle = new Circle(1, "");
            return circle;
        } catch (Exception e) {
            throw new RuntimeException(e);
            // why we cann't do that.
            // throw new Exception(e);
        } finally {
            try {
                conn.close();
            } catch (SQLException e) {
                System.out.println(e);
            }
        }
    }
}

http://stackoverflow.com/questions/3779285/exception-thrown-in-catch-and-finally-clause — Georgian, Sep 12 '13 at 12:31
This is a badly formed question (because of the title), and there isn't really a problem with this code at all. — Software Engineer, Sep 12 '13 at 12:35

score 1 · Accepted Answer · edited May 23 '17 at 10:25

1

We can throw Exception, provided we declare the method to throw the same Exception (throws Exception clause) or handle it (using try catch block) .

Exception is a checked exception and these have to be handled

but

RuntimeException works because its unchecked Exception and for this we need not have a throws clause or handle it

See Checked vs Unchecked Exception

edited May 23 '17 at 10:25

Community

1
1

answered Sep 12 '13 at 12:31

sanbhat

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You don't need to declare runtime exceptions. – Software Engineer Sep 12 '13 at 12:34
Have i mentioned that in the post? why downvote? – sanbhat Sep 12 '13 at 12:35
I just want to know the reason for my concept that's why I asked this question. – Abhi Sep 12 '13 at 15:51

score -2 · Answer 2 · answered Sep 12 '13 at 12:31

-2

Because in that case you will have to declare your method that it throws Exception.

 public Circle getCircle(int id) throws Exception{
Connection conn = null;
try {
    Class.forName("");
    conn = DriverManager.getConnection("");
    PreparedStatement pstmt = conn.prepareStatement("");

    Circle circle = new Circle(1, "");
    return circle;
} catch (Exception e) {
    throw new RuntimeException(e);
    // why we cann't do that.
    // throw new Exception(e);
}

finally {
    try {
        conn.close();
    } catch (SQLException e) {
        System.out.println(e);
    }
}

}

Note:RuntimeException and its subclass are special type exception which don't need to be catched explicitely

answered Sep 12 '13 at 12:31

mawia

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How is it irrelevant? – mawia Sep 12 '13 at 12:34
You don't have to declare runtime exceptions. – Software Engineer Sep 12 '13 at 12:35
That's what I have said and showed in example that it is perfectly okay to throw RuntimeException and but have to declare it if he wish to throw an Exception. – mawia Sep 12 '13 at 12:36

Unable to throw Exception, why?

2 Answers2