How can we handle the ConnectException?

Question

I have searched a lot ,but i couldn't find the fine answer for it.I use try_catch block for this exception(if this exception is thrown one frame will be shown to the user that I will tell him/her a message) but it still show the exception in the console.please help me.Thanks. submit() method which will throw this exception: ``` private void submit() throws ConnectException { String id = idField.getText(); char[] pass1 = passField.getPassword(); String pass = new String(pass1); if (id.equals("") || pass.equals("")) { JOptionPane.showMessageDialog(this, "You should enter an ID and password", "Sign_In Problem", JOptionPane.OK_OPTION); return; } else { boolean b = Manager.Test(id, pass); if (b == true) { this.setVisible(false); Main.runAClient(); ListFrame frame = new ListFrame(client); frame.setVisible(true); } else { JOptionPane.showMessageDialog(this, "You have entered wrong datas,try it again", "Sign_In Problem", JOptionPane.OK_OPTION); return; } } } ``` I work with netbeans,this is a…

Accepted Answer

You posted the code in your previous question: Sign in button has no visible effect in a Java application

Judging by the `runAClient` method, you are logging the exception and eating it up (not throwing it further).

```
public static void runAClient() {
    try {
        c = new Socket("localhost", 5000);
    } catch (UnknownHostException ex) {
        Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
    } catch (IOException ex) {
        Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
    }
}
```

The second catch (`IOException`) should not log and should throw the exception. Actually, you probably want to split that catch into a ConnectException catch which you would throw and a IOException catch which you can handle separately.

Edit: I'll extend this a bit. `ConnectException` extends `RemoteException` which in turn extends `IOException`, which you are catching and logging in your `runAClient` method. You can do two things:

- remove the `IOException` altogether, and catching it at an upper level (a solution which is very ugly in my opinion)

or

- split the `IOException` block into two catch blocks, one for the `ConnectException`, in which you just throw, and one for the rest of the `IOException`s, which you can log (or handle differently) - just make sure the `ConnectException` block is written before the `IOException` block

How can we handle the ConnectException?

Solution

Problem