global class LocationCallouts_2  implements Database.Batchable<sObject>, Database.AllowsCallouts{
        
    Id accountId; 
    Account[] a = [SELECT BillingCity,BillingCountry,BillingPostalCode,BillingState,BillingStreet FROM Account WHERE id =: accountId];
    
    global Iterable<sObject> start(Database.BatchableContext BC){
        return (a);
    }
    
    global void execute(Database.BatchableContext BC, List<sObject> scope){
        Account a = [SELECT BillingCity,BillingCountry,BillingPostalCode,BillingState,BillingStreet FROM Account WHERE id =: accountId];
        String geocodeKey = 'AIzaSyBo-6WwACjhUdg-I81NDtZK87r2xpv8b0U';
        String address = '';
        
        for (sObject s : scope){     
             
            if (a.BillingStreet != null)
                address += a.BillingStreet +', ';
            if (a.BillingCity != null)
                address += a.BillingCity +', ';
            if (a.BillingState != null)
                address += a.BillingState +' ';
            if (a.BillingPostalCode != null)
                address += a.BillingPostalCode +', ';
            if (a.BillingCountry != null)
                address += a.BillingCountry;
            
            address = EncodingUtil.urlEncode(address, 'UTF-8');
            
            Http h = new Http();
            HttpRequest req = new HttpRequest();
            req.setEndpoint('http://maps.googleapis.com/maps/api/geocode/json?address='+address+ '&key='+geocodeKey+'&sensor=false');
            req.setMethod('GET');
            req.setTimeout(60000);
            
            try{
                // callout
                HttpResponse res = h.send(req);
                
                // parse coordinates from response
                JSONParser parser = JSON.createParser(res.getBody());
                double lat = null;
                double lon = null;
                
                while (parser.nextToken() != null){
                    if ((parser.getCurrentToken() == JSONToken.FIELD_NAME) &&
                        (parser.getText() == 'location')){
                            parser.nextToken(); // object start
                            while (parser.nextToken() != JSONToken.END_OBJECT) {
                                String txt = parser.getText();
                                parser.nextToken();
                                if (txt == 'lat')
                                    lat = parser.getDoubleValue();
                                else if (txt == 'lng')
                                    lon = parser.getDoubleValue();
                            }
                        }
                }
                
                // update coordinates if we get back
                if (lat != null){
                    lat = a.Geocodes__Latitude__s;
                    lon = a.Geocodes__Longitude__s;
                    update a;
                }
                
            } 
            catch (Exception e){
            }
            
        }
	//LocationCallouts_2 batch = new LocationCallouts_2();
	//Database.executeBatch(new LocationCallouts_2(),20);
    }
      @future (callout=true)
    public static void startbatch(){
        LocationCallouts_2 batch = new LocationCallouts_2();
        Id batchprocessId = database.executeBatch(batch);
        System.debug('Apex Job Id' + batchprocessId);
    }
    
    global void finish(Database.BatchableContext BC){
        
    }
    
    
}

// Trigger runs getLocation() on Accounts with no Geolocation
/*
trigger SetGeolocation on Account (after insert, after update) 
    {
        for (Account a : trigger.new)
            {
                Boolean addressChangedFlag = false;
                
                if (a.Geocodes__Latitude__s == null)
                    {
                        LocationCallouts.getLocation(a.id);
                    }
            }
    }
*/

trigger SetGeolocation on Account (after insert, after update) 
    {
        for (Account a : trigger.new)
            {
                Boolean addressChangedFlag = false;
                
                if (a.Geocodes__Latitude__s == null)
                    {
                        Database.executeBatch(new LocationCallouts_2());
                    }
            }
    }