Is it possible to have empty RequestParam values use the defaultValue?
Here, Spring's @RequestParam
is implemented with a defaultValue
attribute. This ensures a fallback option when the request parameter is empty, ensuring your application is safeguarded against null values.
Guard against null and blank parameters
In some cases, we might unexpectedly receive null or empty strings as parameters. This can cause a NumberFormatException
, especially when dealing with numeric types. To gracefully handle these edge cases, we can assign the @RequestParam
to a String type and parse it manually.
Safeguarding against type mismatch
In the example above, it's ensured that param
is non-null and non-blank before trying to parse it. If it doesn't pass these checks, we conveniently set it to the well-known number 42, bypassing any NumberFormatException
.
Embrace Spring updates
Spring version 3.2.2 onwards does this heavy lifting for us. The framework intelligently uses the defaultValue
for empty parameters making your code tidy and efficient.
Compatibility across Spring versions
Consider using @Nullable
annotation. It clarifies your intent and aids compatibility with different Spring versions. Moreover, preventing empty parameters on the client side saves us from many unwanted surprises.
Exploring edge cases and alternatives
Enforce client-side validation
Trimming the problem at its root, ensure front-end validation prevents empty inputs from being sent, prompting the user to fill valid inputs beforehand.
Use type conversion service
A custom type conversion service in Spring could be just what you need. This service translates empty request parameter strings to null values or appropriate defaults for various data types.
Embrace global fallback configuration
When you have common default values across endpoints, configuring a global fallback removes redundancy, making your code DRY and easy to maintain.
Stay updated with documentation
Stay enlightened about issues like SPR-10180 and keep an eye on the Spring documentation. This helps you remain updated about the changes in how @RequestParam
behaves across different versions.
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