Attempting to post Case parameters to external system

Question

I'm a beginner in webservices and future calls. I have been trying post parameters to an external system (ServiceNow). As of now I'm able to post a generic description field from Salesforce to ServiceNow.

Here's what I have tried so far..

trigger Case2ServiceNow on Case (after insert) {
for(Case c : [Select Id, RecordTypeId, RecordType.Name,Subject From Case Where Id IN : Trigger.new]) {
if(c.RecordType.Name == 'Incident'){
    AuthCalloutPost.basicAuthCalloutPost();
  //  uniqueNames.add(c.Subject);
   }
else{
    System.debug('##false##');
 }
}   
}

here's the class...

public class AuthCalloutPost{
public String Response { get; set;}

@future(callout=true)

public static void basicAuthCalloutPost(String names){
HttpRequest req = new HttpRequest();
req.setEndpoint('xxx/api/now/table/incident');
req.setMethod('POST');
String postData = '{\"short_description\":\" Posting from Salesforce.com case trigger\"}';
req.setBody(postData);
req.setTimeout(120000);

 String authorizationHeader = 'Basic xyz=';
 req.setHeader('Authorization', authorizationHeader);
 req.setHeader('Accept', 'application/json');
 req.setHeader('Content-Type', 'application/json'); 
 req.setHeader('Accept', 'application/json');

 Http http = new Http();
 HTTPResponse res = http.send(req);
 System.debug(res.getBody());
 // this.response=res.getBody();

  }
  }

I'm trying to post Salesforce Case parameters to the ServiceNow like name, description. I would really appreciate if I'm pointed to the right direction. Thanks in advance.

UPDATE: when I comment //req.setBody(requestbody); and post this instead, it works! String postData = '{\"short_description\":\"Posting a Sentence\"}'; req.setBody(postData); I'm still not able to figure out the issue in Json generation.

Answer 1

You can't pass sObjects in future method so you will pass all the object ids and after that you can query data inside future method and generate your JSON which you will pass to your external service so your code can be modified in following way

1. Trigger code

   trigger Case2ServiceNow on Case (after insert) {
     AuthCalloutPost.basicAuthCalloutPost(Trigger.newmap.keyset());
   }
   

2. Your class code

   public class AuthCalloutPost{
   public String Response { get; set;}
   
   @future(callout=true)
   
    public static void basicAuthCalloutPost(set<id> caseids){
   
    //call to generate request body
    String requestbody = generateBody(caseids);
   
    HttpRequest req = new HttpRequest();
    req.setEndpoint('xxx/api/now/table/incident');
    req.setMethod('POST');
   
    req.setBody(requestbody);
    req.setTimeout(120000);
   
    String authorizationHeader = 'Basic xyz=';
    req.setHeader('Authorization', authorizationHeader);
    req.setHeader('Accept', 'application/json');
    req.setHeader('Content-Type', 'application/json'); 
    req.setHeader('Accept', 'application/json');
   
    Http http = new Http();
    HTTPResponse res = http.send(req);
    System.debug(res.getBody());
    // this.response=res.getBody();
   
    }
   
    //This method will generate request body.
    public static String generateBody(set<id> casesids)
    {
          JSONGenerator gen = JSON.createGenerator(true);
          gen.writeStartObject();
          gen.writeFieldName('Cases');
          gen.writeStartArray();
          for(Case c : [Select Id, RecordTypeId, RecordType.Name,Subject       
            From Case Where Id IN : casesids]) {
            if(c.RecordType.Name == 'Incident'){
              //define different fields which you want to pass.
              gen.writeStartObject();
              gen.writeStringField('RecordTypeName', c.RecordType.Name);  
              gen.writeStringField('short_description',c.Subject);
              gen.writeStringField('RecordTypeId',c.RecordTypeId);
              gen.writeEndObject();   
            } 
   
         }  
              gen.writeEndArray();
              gen.writeEndObject();
              return gen.getAsString(); 
    }
   
   }