Antlr Error / Exception Handling

After several online research, I found that this would be a way to catch exceptions and output my own error messages. For some reason, I still can't catch the errors. Below is the code for a class that overrides antlrs default error handling.

All I want to do is to catch an exception from antlr and display that the syntax is incorrect in java gui.

public class ExceptionErrorStrategy extends DefaultErrorStrategy {

@Override
public void recover(Parser recognizer, RecognitionException e) {
    throw e;
}

@Override
public void reportInputMismatch(Parser recognizer, InputMismatchException e) throws RecognitionException {
    String msg = "Input is mismatched " + getTokenErrorDisplay(e.getOffendingToken());
    msg += " expecting: "+e.getExpectedTokens().toString(recognizer.getTokenNames());
    RecognitionException ex = new RecognitionException(msg, recognizer, recognizer.getInputStream(), recognizer.getContext());
    ex.initCause(e);
    throw ex;
}

@Override
public void reportMissingToken(Parser recognizer) {
    beginErrorCondition(recognizer);
    Token t = recognizer.getCurrentToken();
    IntervalSet expecting = getExpectedTokens(recognizer);
    String msg = "Missing "+expecting.toString(recognizer.getTokenNames()) + " at " + getTokenErrorDisplay(t);
    throw new RecognitionException(msg, recognizer, recognizer.getInputStream(), recognizer.getContext());
}
}
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