Error [System.HttpResponse[Status=Unauthorized, StatusCode=401]] when updating currency table

Code:

global class CurrencyExchangeRateScheduler implements Schedulable
{
    public String sessionId;

    public CurrencyExchangeRateScheduler()
    {
        String username = 'username';
        String password = 'password+security_token';

        partnerSoapSforceCom.Soap sp = new partnerSoapSforceCom.Soap();

        partnerSoapSforceCom.LoginResult loginResult = sp.login(username, password);

        sessionId = loginResult.sessionId;

    }

    global void execute(SchedulableContext ctx)
    {
        UpdateDailyCurrencyExchangeRate(sessionId);
    }

    @Future(callout=true)
    public static void UpdateDailyCurrencyExchangeRate(string sessionId)
    {
        system.debug('sessionId: '+sessionId);
        ...

        Http h = new Http();
        HttpRequest req = new HttpRequest();
        req.setHeader('Authorization', 'OAuth ' + sessionId);
        req.setHeader('Content-Type', 'application/json');
        req.setMethod('POST');

        for(CurrencyType currType : currencies)
        {
            if(!currType.IsCorporate)
            {
                req.setEndpoint(URL.getSalesforceBaseUrl().toExternalForm() + '/services/data/v28.0/sobjects/CurrencyType/'+currType.id+'?_HttpMethod=PATCH');

                req.setBody('{ "ConversionRate" : 2.5 }');

                HttpResponse response = h.send(req);    

                system.debug('response: '+response);
             }
        }
    }
}

Debug: response: System.HttpResponse[Status=Unauthorized,
StatusCode=401]

I also tried with the Authorization header as Bearer + sessionId.

But again the same issue.

The code works perfectly fine when I am loggedin to the org. But when the class is scheduled and I am not loggedin, the response status is ‘Unauthorized’ and the currency table is not updated.

How can I get the session Id when User is not loggedin?

Answers:

Thank you for visiting the Q&A section on Magenaut. Please note that all the answers may not help you solve the issue immediately. So please treat them as advisements. If you found the post helpful (or not), leave a comment & I’ll get back to you as soon as possible.

Method 1

When you schedule a class its execution is postpone to the future time.

While actually executing it the session id you passed may not be valid, so you have 2 options.

1) Extended the session validity by -> Setup->Security Controls-> Session settings and set session time out to MAX (12 hours)
(Hopefully your code will be extended in next 12 hours)

2) Modify your UpdateDailyCurrencyExchangeRate method to include login call.

@Future(callout=true)
public static void UpdateDailyCurrencyExchangeRate()
{

    String username = 'username';
    String password = 'password+security_token';

    partnerSoapSforceCom.Soap sp = new partnerSoapSforceCom.Soap();

    partnerSoapSforceCom.LoginResult loginResult = sp.login(username, password);

    sessionId = loginResult.sessionId;

    system.debug('sessionId: '+sessionId);


    Http h = new Http();
    HttpRequest req = new HttpRequest();
    req.setHeader('Authorization', 'OAuth ' + sessionId);
    req.setHeader('Content-Type', 'application/json');
    req.setMethod('POST');

    for(CurrencyType currType : currencies)
    {
        if(!currType.IsCorporate)
        {
            req.setEndpoint(URL.getSalesforceBaseUrl().toExternalForm() + '/services/data/v28.0/sobjects/CurrencyType/'+currType.id+'?_HttpMethod=PATCH');

            req.setBody('{ "ConversionRate" : 2.5 }');

            HttpResponse response = h.send(req);    

            system.debug('response: '+response);
         }
    }
}

Method 2

The below link helps you to fix your issue. i too had previously same issue so i started a thread and got the solution. Check it once.
SessionID problem in Schedule Batch class

Method 3

If authentication error occurs as 401-Unauthorized Header, even after using the correct http headers, try replacing the org instance in the endpoint with instance_url returned from authentication token web callout.

        Http h1 = new Http();   
        HttpRequest req1 = new HttpRequest();
        **req1.setHeader('Authorization','Bearer '+ objAuthenticationInfo.access_token);**
        req1.setHeader('Content-Type','application/json');
        req1.setHeader('Accept','application/json');
        req1.setMethod('GET');
        req1.setEndpoint(objAuthenticationInfo.instance_url+'/services/data/v47.0/query/?q=SELECT+name+from+account');
        HttpResponse res1 = h1.send(req1);

All methods was sourced from stackoverflow.com or stackexchange.com, is licensed under cc by-sa 2.5, cc by-sa 3.0 and cc by-sa 4.0