All exceptions support built-in methods for returning the error message and exception type. In addition to the standard exception class, there are several different types of exceptions:
The following are exceptions in the System namespace.
Exception | Description |
---|---|
AsyncException | Any problem with an asynchronous operation, such as failing to enqueue an asynchronous call. |
CalloutException | Any problem with a Web service operation, such as failing to make a callout to an external system. |
DmlException | Any problem with a DML statement, such as an insert statement missing a required field on a record. |
EmailException | Any problem with email, such as failure to deliver. For more information, see Outbound Email. |
ExternalObjectException | Any problem with external object records, such as connection timeouts during attempts to access the data that’s stored on external systems. |
InvalidParameterValueException | An invalid parameter was supplied for a method or any problem with a URL used with Visualforce pages. For more information on Visualforce, see the Visualforce Developer's Guide. |
LimitException | A governor limit has been exceeded. This exception can’t be caught. |
JSONException | Any problem with JSON serialization and deserialization operations. For more information, see the methods of System.JSON, System.JSONParser, and System.JSONGenerator. |
ListException | Any problem with a list, such as attempting to access an index that is out of bounds. |
MathException | Any problem with a mathematical operation, such as dividing by zero. |
NoAccessException | Any problem with unauthorized access, such as trying to access an sObject that the current user does not have access to. This is generally used with Visualforce pages. For more information on Visualforce, see the Visualforce Developer's Guide. |
NoDataFoundException | Any problem with data that does not exist, such as trying to access an sObject that has been deleted. This is generally used with Visualforce pages. For more information on Visualforce, see the Visualforce Developer's Guide. |
NoSuchElementException | This exception is thrown if you try to access items that are outside the bounds of a list. This exception is used by the Iterator next method. For example, if iterator.hasNext() == false and you call iterator.next(), this exception is thrown. This exception is also used by the Apex Flex Queue methods and is thrown if you attempt to access a job at an invalid position in the flex queue. |
NullPointerException | Any problem with dereferencing null, such as in the following
code:String s; s.toLowerCase(); // Since s is null, this call causes // a NullPointerException |
QueryException | Any problem with SOQL queries, such as assigning a query that returns no records or more than one record to a singleton sObject variable. |
RequiredFeatureMissing | A Chatter feature is required for code that has been deployed to an organization that does not have Chatter enabled. |
SearchException | Any problem with SOSL queries executed with SOAP API search() call, for example, when the searchString parameter contains less than two characters. For more information, see the SOAP API Developer's Guide. |
SecurityException | Any problem with static methods in the Crypto utility class. For more information, see Crypto Class. |
SerializationException | Any problem with the serialization of data. This is generally used with Visualforce pages. For more information on Visualforce, see the Visualforce Developer's Guide. |
SObjectException | Any problem with sObject records, such as attempting to change a field in an update statement that can only be changed during insert. |
StringException | Any problem with Strings, such as a String that is exceeding your heap size. |
TypeException | Any problem with type conversions, such as attempting to convert the String 'a' to an Integer using the valueOf method. |
VisualforceException | Any problem with a Visualforce page. For more information on Visualforce, see the Visualforce Developer's Guide. |
XmlException | Any problem with the XmlStream classes, such as failing to read or write XML. |
The following is an example using the DmlException exception:
Account[] accts = new Account[]{new Account(billingcity = 'San Jose')}; try { insert accts; } catch (System.DmlException e) { for (Integer i = 0; i < e.getNumDml(); i++) { // Process exception here System.debug(e.getDmlMessage(i)); } }
Exception methods are all called by and operate on a particular instance of an exception. The table below describes all instance exception methods. All types of exceptions have the following methods in common:
In addition to the common exception methods, DMLExceptions and EmailExceptions have the following additional methods:
Name | Arguments | Return Type | Description |
---|---|---|---|
getDmlFieldNames | Integer i | String [] | Returns the names of the field or fields that caused the error described by the ith failed row. |
getDmlFields | Integer i | Schema.sObjectField [] | Returns the field token or tokens for the field or fields that caused the error described by the ith failed row. For more information on field tokens, see Dynamic Apex. |
getDmlId | Integer i | String | Returns the ID of the failed record that caused the error described by the ith failed row. |
getDmlIndex | Integer i | Integer | Returns the original row position of the ith failed row. |
getDmlMessage | Integer i | String | Returns the user message for the ith failed row. |
getDmlStatusCode | Integer i | String | Deprecated. Use getDmlType instead. Returns the Apex failure code for the ith failed row. |
getDmlType | Integer i | System.StatusCode | Returns the value of the System.StatusCode enum. For example:try { insert new Account(); } catch (System.DmlException ex) { System.assertEquals( StatusCode.REQUIRED_FIELD_MISSING, ex.getDmlType(0)); } For more information about System.StatusCode, see Enums. |
getNumDml | Integer | Returns the number of failed rows for DML exceptions. |