How to Write Error Handling in Micronaut

Reading Time: 3 minutes

I’m going to walk you through the process of writing error handling in Micronaut which is a very simple, but powerful way, to manage errors.

Why is Error Handling Important

Error handling is important because it allows you to gracefully handle unexpected errors in your code. By providing custom error handling, you can provide a better user experience by providing more informative error messages and by directing the user to the appropriate resources for help. Additionally, proper error handling can help prevent your code from crashing or behaving unexpectedly.

What is an Exception

When we talk about Exception Handling, there are two primary types of errors that we need to consider: checked and unchecked. Checked exceptions are those that the compiler forces you to deal with, whereas unchecked exceptions are not. In order to write error handling in Micronaut, you will need to use try/catch blocks for both types of errors.

Checked exceptions occur at compile time, such as when you try to reference a non-existent file. To handle these, you must wrap your code in a try block and catch the specific exception type that could be thrown. For example:

try { 

 // Code which may throw a checked exception 

} catch (IOException e) { 

     // Handle the exception here 
}

Unchecked exceptions are those which occur at runtime, such as when you try to divide by zero. These do not need to be caught by a try/catch block but can be if you want to handle them specifically. However, it is generally good practice to let these propagate up the call stack so that they can be dealt with at a higher level. For example:

// Code which may throw an unchecked exception 

int result = 10 / 0;  // Throws an ArithmeticException

How to Handle Exceptions in Micronaut

When you are writing code in Micronaut, it is important to be aware of how to handle exceptions. This is especially true when you are working with data sources, such as databases or web services.

There are two main ways to handle exceptions in Micronaut: try/catch blocks and error-handling interceptors.

Try/catch blocks are the most common way to handle exceptions in Java code. You can use them to wrap code that might throw an exception and handle the exception if it does occur. For example:

try {

  // Code that might throw an exception

} catch (Exception e) {

  // Handle the exception

}

Error handling interceptors are a special type of interceptor that are invoked when an exception is thrown. They can be used to do things like log the exception or send an email notification about the error. To use an error handling interceptor, you need to add it to your Micronaut configuration file:

micronaut:

  interceptors:

    - class: com.example.myapp.interceptors.MyErrorHandlingInterceptor

The Error class

The Error class is the base class for all errors in Micronaut. It provides the following methods:

  • getMessage(): Returns the error message.
  • getCause(): Returns the cause of the error, if any.
  • toString(): Returns a string representation of the error.
  • printStackTrace(): Prints a stack trace of the error to standard error.

The Exception class

The Exception class is the base class for all exceptions in Micronaut. It provides common functionality for all exceptions, such as storing a stack trace.

Conclusion

In conclusion, error handling in Micronaut is a crucial aspect of developing applications with this framework. By understanding how to properly handle errors, you can ensure that your application will be able to gracefully recover from any unexpected situations. With the tips and techniques in this article, you should now be well-equipped to tackle error handling in your own Micronaut applications.

HAPPY LEARNING!

Written by 

Gaurav srivastav is a Software Consultant working in java domain.

Leave a Reply