I have a piece of code that show above error on

     d.FolderId = UserInfo.getUserId();
     d.Name = 'Data2'; 
     String myContent = this.name+ '\n ' +this.pass+ '\n ' + this.age+ '\n ' +this.mail; 
     d.body += Blob.valueof(mycontent);
     d.ContentType = 'text/plain';
     d.Type = 'txt';
     upsert d;
     return null;

 d.body += Blob.valueof(mycontent);(Show error in this line)

Blob just doesn't work that way. You need to build up one string, and call Blob.valueOf at the end. For instance, you could do:

Blob.valueOf(myContent + myContent);

Which seems to be what you want in your example. Or, as an alternative to the code in the flagged duplicate:

Blob.valueOf('s1' + 's2' + 's3');

If you want to append to the Body, you first need to extract the value of the Body Blog as a string so you can append. Try this:

Blob firstBlob = Blob.valueOf('test');
String firstString = firstBlob.toString();
Blob secondBlob = Blob.valueOf(firstString + 'test');

For a concrete example, try this:

Account acct = [SELECT Id FROM Account LIMIT 1];
Attachment attch = new Attachment();
attch.ParentId = acct.Id;
attch.Name = 'Data2';
attch.Body = Blob.valueOf('test');
insert attch;

String blob2String = attch.Body.toString();
Blob secondBlob = Blob.valueOf(blob2String + 'secondtest');

attch.Body = secondBlob;
update attch;

This outputs 'testsecondtest' for me.

I'm not sure of what the d object is, but I suspect that you should try to catch the error on insert - because it's probably unrelated to the Blob

  • But that is way less efficient if you already know the string value of firstBlob, no? – Adrian Larson Aug 30 '16 at 18:13
  • Sure, but I think @Bonny to append to an already encoded Body from what they said. – Caspar Harmer Aug 30 '16 at 18:16
  • Right, but my point is that it sounds like firstString is already known. That's why I didn't include this approach, anyway. Still, if you didn't already know firstString, this would be the way to go, you're right. – Adrian Larson Aug 30 '16 at 18:18
  • 1
    Good point - oh well, bonny now has both options :) – Caspar Harmer Aug 30 '16 at 18:19
  • Hi Casper I did Some changes in my code but its not Append still Here is my Code d.FolderId = UserInfo.getUserId(); d.Name = 'Data2'; system.debug('d.body==='+d.body); String myContent = this.name+ '\n ' +this.pass+ '\n ' + this.age+ '\n ' +this.mail; d.body= Blob.valueof(mycontent); string s1 = d.body.tostring()+mycontent;string s1 = d.body.tostring(); d.body = blob.valueof(s1); d.ContentType = 'text/plain'; d.Type = 'txt'; upsert d; return null; – Bonny Sep 5 '16 at 7:58

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.