GoogleUrlShortener.cls

global class GoogleUrlShortener
{
    webservice static string shortenUrl(string longUrl)
    {
        Http http = new Http();
        HttpRequest httpReq = new HttpRequest();
        HttpResponse httpRes = new HttpResponse();
        String body='';
        
        httpReq.setMethod('POST');
        httpReq.setHeader('Content-Type', 'application/json');
        httpReq.setEndpoint('https://www.googleapis.com/urlshortener/v1/url?key=<YOUR-API-KEY-HERE>');
        
        body = '{\"longUrl\": \"' + longUrl + '\"}';
        
        httpReq.setHeader('Content-Length', String.valueOf(body.length()));
        httpReq.setBody(body);
        
        try{
            httpRes = http.send(httpReq);
            
            String shortUrl = parseJSON(httpRes.getBody(), 'id');
            
            return shortUrl;
        }
        catch(Exception e){
            System.debug('Class: GoogleUrlShortener; ' + 'Method: (WS)ShortenUrl; Message: ' + e.getMessage());
            
            return 'Error';         
        }
    }
    
    private static string parseJSON(String jsonText, String node)
    {
        JSONParser parser = null;
        
        parser = JSON.createParser(jsonText);
        
        while (parser.nextToken() != null)
        {
            if(parser.getText()==node)
            {
                parser.nextToken();
                return parser.getText();
            }         
        }
        
        return 'Error';
    }    
}