No Viable Alternative at character ' ' - salesforce

Question

Hi i am getting the following error in this code
/*
Class : CreateMobileChatterCntrl
Description : Post Chatter on Contact.
Developed by : Harish Khatri(Appirio Offshore)
Created Date : June 2, 2012
*/
public without sharing class CreateMobileChatterCntrl {
public final Id ContactID{get;set;}
public String message{get;set;}
public boolean isSuccess{get;set;}
public boolean throwError{get;set;}
public String deviceType{get;set;}
//----------------------------------------------------------------------------
//constructor
//----------------------------------------------------------------------------
public CreateMobileChatterCntrl() {
throwError = false;
isSuccess = false;
if( ApexPages.CurrentPage().getParameters().get('id') != null){
ContactID = ApexPages.CurrentPage().getParameters().get('id');
}
String userAgent = ApexPages.currentPage().getHeaders().get('USER-AGENT');
if(userAgent.contains('iPhone'))
deviceType = 'iPhone';
//else if(userAgent.contains('Android')) deviceType = 'Android';
}
//----------------------------------------------------------------------------
// Post the chatter on contact
//----------------------------------------------------------------------------
public Pagereference save() {
if(message == null || message ==''){
throwError = true;
return null;
}
FeedItem feedItem = new FeedItem();
feedItem.ParentId = ContactID;
feedItem.Body = message;
try {
insert feedItem;
isSuccess = true;
} catch(Exception e){}
return null;//new PageReference('/' + ContactID);
}
public Pagereference cancel() {
return new PageReference('/' + ContactID);
}
}
public final Id ContactID{get;set;} at this line i am getting the error No Viable Alternative at character ' '.can any one please help why i am getting this error??

Answer 1

Some of the single quote characters in your class file are invalid --- perhaps because you copied and pasted the code from somewhere else. I've had this happen many times before when I've copied code from elsewhere. Starting with the quotes in: message == '' , i'd delete the single quotes, retype them, and resave your file. Repeat for all single quotes (or do a find and replace).