Best PracticesException Handling

Abid Hossain Khan

Agenda

Advantages

Exception Hierarchy

Best Practices

Advantages

Represent a meaningful message to user

Log unhandled exception once and only once

Correlate exceptions with unique request id (session) in log file for high precision debugging

Implement powerful but extensible exception handling strategy for each tiers

Exception Hierarchy

Best Practice : 1

Never swallow exception in catch block

Best Practice : 2

Declare the specific checked exceptions that your method can throw

Best Practice : 3

Do not catch the Exception class rather catch specific sub classes

Best Practice : 4

• Never catch Throwable class

Best Practice : 5

Always correctly wrap the exceptions in custom exceptions so that stack trace is not lost

Best Practice : 6

Either log the exception or throw it but never do the both

Best Practice : 7

Never throw any exception from finally block

Best Practice : 8

Always catch only those exceptions that you can actually handle

Best Practice : 9

Don’t use printStackTrace() statement or similar methods

Best Practice : 10

Use finally blocks instead of catch blocks if you are not going to handle exception

Best Practice : 11

Throw early catch late

Best Practice : 12

Always clean up after handling the exception

Best Practice : 13

• Throw only relevant exception from a method

Best Practice : 14

Never use exceptions for flow control in your program

Best Practice : 15

Always include all information about an exception in single log message

Best Practice : 16

Use template methods for repeated try-catch

Best Practice : 17

Document all exceptions in your application in javadoc

Thank You