Last updated: 2022-11-03
Bind empty String as null in Spring Boot
When a form is submitted with an input field without any data, the browser submits it as an empty string ""
. That's why Spring Boot writes this to the data object exactly this way - with a StringTrimmerEditor
configuration in place, we can bind the value as null
instead.
Configuration to convert empty Strings to null
The above ControllerAdvice
adds a new editor to our WebDataBinder
. StringTrimmerEditor
first removes all spaces at the beginning and end of the submitted form data (trim) - this is usually just an incorrect input from the user. With the parameter true
empty Strings will also be converted to null
.
This saves us from handling different cases separately and allows us to persist the data directly into the database, where we prefer to store a null
value when no information was provided.
Bootify is a tool to intialize Spring Boot applications with its own database schema, an optional Thymeleaf frontend with CRUD functionalities and many more features on top - online in the browser without registration. When a frontend is selected, the StringTrimmerEditor
is also provided exactly as described above.
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