[SalesForce] Batch Apex – System.CalloutException: You have uncommitted work pending. Please commit or rollback before calling out

I am getting

System.CalloutException: You have uncommitted work pending. Please
commit or rollback before calling out.

global class BatchClassName implements Database.Batchable<`string`>,
                                       Database.Stateful, 
                                       Database.AllowsCallouts {

    //Local Variables
    global list<string> lstTeamAssignedOfficerId;
    global final list<string> lstAccountOfficerId;

    global <BatchClassName_Constructor>(list<string> lstAccountOfficer) {
        this.lstAccountOfficerId = new list<string>();
        this.lstAccountOfficerId = lstAccountOfficer;
    }

    global Iterable<string> start(Database.BatchableContext ctx) {
        return lstAccountOfficerId;
    }

    global void execute(Database.BatchableContext ctx, list<string> lstAccountOfficer) {
        /*Performing All SOQL and DML operations - No Callouts performed*/
    }

    global void finish(Database.BatchableContext ctx) {
        /*Performing Callout */        
    }
}

I think Finish method will execute after the all the Batches are completed and data is commit in objects. I have written code in past to perform callout in Finish Method and DML operations in execute method.

Best Answer

I Identified the issue in Batch Class code. There was a DML operation between callouts which was causing this.

Thanks for your help @Eric.

believe since you are implementing database.stateful that the DML persits and thus you cannot make a callout in the finish method

Database.stateful is to persist values of instance variables and not for DML operations. Issue was in Finish method code, while doing 4 difffenent APEX callouts code was inserting records(DML) inbetween callouts. I just moved all the DML statements after callouts to resolve the issue.

Related Solutions

[SalesForce] Apex Batch : You have uncommitted work pending. Please commit or rollback before calling out

Problem

Actually, webservice or http callouts and a DML won't take place in the same transaction. And that's why you are getting the error. Read about this problem.

Solution

You could break your code into two parts, as per the suggestion in the above article, Webservice part and the DML part.
Use @Future annotation. I had such problem and resolved using that.

Code Sameple This is just a out-of-mind code. but you need make changes or test this as per your need.

//global variable at the top
Map<String,Object> mapObject;
//start ()
execute () {
      CallWebService();
      Map<String,Object> rawObj = mapObject;
      // Your remaining code
}

@future
public PageReference CallWebService() {
    // initialize the global variable.
    mapObject = new Map<String,Object>();


    HttpRequest req = new HttpRequest();
    req.setMethod('GET');
    req.setEndpoint('https://www.publicstuff.com/api/2.0/request_view?request_id='+newReq');
    Http http = new Http();
    HTTPResponse res = http.send(req);

    String resonseBody = res.getBody();
    String jsonString = resonseBody;
    mapObject = (Map<String,Object>) JSON.deserializeUntyped(jsonString);
}

[SalesForce] API Callout (apex class) from workflow – You have uncommitted work pending,please commit before calling out

You can't callout during the life cycle of a DML operation directly. This limitation was put in place to prevent excessive row lock times. You can callout and perform DML in the same transaction, provided you callout first. Usually, this means you need to perform your callout asynchronously:

global class invokeAreasCallout{
    @InvocableMethod(label='Areas Callout')
    //global static List<String> doAreaCallout(List<String> postcode) {
    global static List<String> doAreaCallout() {
        doAreaCalloutAsync();
        return null;
    }
    @future(callout=true) global static void doAreaCalloutAsync() {
        String postcode='B302PF';
        HttpResponse res;
        // Instantiate a new http object
        Http h = new Http();

        // Instantiate a new HTTP request, specify the method (GET) as well as the endpoint
        HttpRequest req = new HttpRequest();
        String requestURL='http://mapit.mysociety.org/postcode/';
        requestURL=requestURL+postcode;
        req.setEndpoint(requestURL);
        req.setMethod('GET');

        // Send the request, and return a response
        res = h.send(req);
    }
}

Note that this means you can't get the results from your callout during the initial record transaction, so you'll probably want to modify your invocable method to accept a list of record ID values, and perform a query in the future method (then callout, and finally commit any changes back to the database).

Related Topic

[SalesForce] What can cause “System.CalloutException: You have uncommitted work pending. Please commit or rollback before calling out”