Apex class -

@RestResource(urlMapping='/account')

global class createAccount 
{    

    @HttpPost
    global static void createAcc() 
    {

        //-- Data coming from request
        String strFirstName = RestContext.request.params.get('First_Name');
        String strLastName = RestContext.request.params.get('Last_Name');
        String strPhone = RestContext.request.params.get('Phone');
        String strEmail = RestContext.request.params.get('Email');
        String strTitle = RestContext.request.params.get('Title');

        system.debug('RestContext.request.params: '+RestContext.request.params);

        system.debug('First_Name: '+strFirstName);
        system.debug('Last_Name: '+strLastName);
        system.debug('Phone: '+strPhone);
        system.debug('Email: '+strEmail);
        system.debug('Title: '+strTitle);
   }
}

When I check the debug log, the last debug statement shows null value.

12:17:31.033 (33840000)|USER_DEBUG|[21]|DEBUG|RestContext.request.params: {Email=abc@gmail.com, First_Name=FirstName, Last_Name=LastName, Phone=+1234567890, ​Title=Mr}
12:17:31.033 (33886000)|USER_DEBUG|[23]|DEBUG|First_Name: FirstName
12:17:31.033 (33929000)|USER_DEBUG|[24]|DEBUG|Last_Name: LastName
12:17:31.033 (33963000)|USER_DEBUG|[25]|DEBUG|Phone: +1234567890
12:17:31.033 (33998000)|USER_DEBUG|[26]|DEBUG|Email: abc@gmail.com
12:17:31.034 (34035000)|USER_DEBUG|[27]|DEBUG|Title: null

POST https://cs10.salesforce.com/services/apexrest/account?First_Name=FirstName&Last_Name=LastName&Phone=+1234567890&Email=abc@gmail.com&​Title=Mr

Attribution to: Swati

Possible Suggestion/Solution #1

As a starting point, I recreated you class and request. Using the dev console the output was properly displayed. Check to ensure your URL you are creating does not include and special characters before Title. Your paste also seems to strip off the Title=Mr in the URL. Again, recreating and calling from the dev console works just fine

Attribution to: Eric
This content is remixed from stackoverflow or stackexchange. Please visit https://salesforce.stackexchange.com/questions/34668