How to fix SQLException in the Catch Statement?

This program is about auto complete. When I type something to the textfield, a list of suggestions will appear.

I make the method onWordUpdated() for a list of suggestions from the DB when I type something to the textfield.

Now, the problem is I have this error:

exception java.sql.SQLException is never thrown in body of corresponding try statement

I made a comment in the code so that you will know which line.

Could someone help me how to fix this?

thanks..

I have this code:

public void onWordUpdated(final String toComplete)
  {
    new Thread(new Runnable()
    {
      public void run()
      {
        try
        {
          final List<Suggestion> suggestions = suggestor.getSuggestions(toComplete);
          SwingUtilities.invokeLater(new Runnable()
          {
            public void run()
            {
              try
              {
                suggestionWidgetModel.clear();
                for (Suggestion suggestion : suggestions)
                  suggestionWidgetModel.addElement(suggestion.getCaption());
                if (!suggestions.isEmpty())
                  suggestionWidget.setSelect开发者_JAVA百科edIndex(0);
              }
              catch (SQLException e) // This line is my problem, Could someone help me how to fix this? Thanks.. 
              {
                e.printStackTrace();
              }
            }
          });
        }
        catch (SQLException e1)
        {
          onSqlError(e1);
        }
      }
    }, "onWordUpdated").start();
  }

The compiler is simply telling you that you don't need to catch that exception at that point.

SQLException is a checked exception, which means that your code should only see it if you either explicitly throw it, or you call a method that declares it in its throws clause. Neither of these is true for the code in that particular try/catch block.

You should be able to just get rid of the inner try/catch block and probably the outer one too.

^{IIRC, it is theoretically possible to see checked exceptions that haven't been declared, but this unlikely to arise unless you take special steps to make it happen.}

Java has two types of exceptions: unchecked (those that inherit from RuntimeException or Error) and checked (all others that inherit from Exception).

A checked exception has the following properties:

• If a block of code throws one, it must be caught in a catch block or the method must declare that it may throw that type of Exception.
• If some code calls a method that throws SomeException, that code must also be in a try-catch or its method must also specify throws SomeException.

Because of the first two checks, the compiler can detect whether a checked exception can actually be thrown in a certain block of code. As a result, this leads to a third property:

• If the catch clause of a try-catch block declares an Exception type that cannot occur in the try block, then a compile error is generated. The compiler does this primarily to tell you that you've made an error: you're dealing with an exception that will never be thrown.

SQLException is a checked exception so it is subject to those rules. None of the lines of code (or the methods they call) in the try block below can ever throw a SQLException so the compiler tells you via a compile error.

try {
    suggestionWidgetModel.clear();
    for (Suggestion suggestion : suggestions)
        suggestionWidgetModel.addElement(suggestion.getCaption());
    if (!suggestions.isEmpty())
        suggestionWidget.setSelectedIndex(0);
}
catch (SQLException e) // This line is my problem, Could someone help me how to fix this? Thanks.. 
{
    e.printStackTrace();
}