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How do I catch an exception being thrown in a setter bound to a VisualForce input?
public Decimal latitude {
  get {
    return (Decimal)self.get('latitude__c');
  }
  set {
    self.put('latitude__c', value);
  }
}

<apex:inputtext value="{!latitude}" />

try{
   latitude = Decimal.valueOf(latitude);
}catch (exception e){
   ApexPages.addMessage(new ApexPages.Message(ApexPages.severity.Error, 'Invalid latitude entered!'));
}