RequestParam default value boolean

1. Overview

In this article, we will discuss setting a default boolean value for Spring RequestParam. To know the difference between @RequestParam and @PathVariable, refer to this article.

2. Spring RequestParam

The�?@RequestParam�?annotation binds the request parameters to a method parameter in your controller.

For example, the below getOrders handler method of the Orders controller handles all the incoming HTTP GET requests with path /orders. The request param maps the query param since to the method parameter sinceDate.

@RestController
public class OrdersController {
    Logger logger = (Logger) LoggerFactory.getLogger(OrdersController.class);
    @GetMapping("/orders")
    public String getOrders(@RequestParam(name = "since", required = false) String since) {
        logger.debug("Orders since " + since);
        return "Orders since: " + since;
    }
}

When you hit the URI http://localhost:8080/orders?since=2021-10-21, then the above getOrders function filters the order created after the date Oct 21st, 2021.

By default, @RequestParam requires query parameters to be present in the URI. However, you can make it optional by setting�?@RequestParam‘s�?required�?attribute to�?false. In the above example, the since query param is optional:�?@RequestParam(value="since", required=false)).

The @RequestParam annotation supports the following parameters:

• defaultValue: Default value as a fallback mechanism when the request doesn’t have a value or is empty.
• name: Name of the query parameter to bind
• required: Whether the parameter is mandatory. By default, it is true.
• value: An alternative alias for the name attribute

3. RequestParam default value for Boolean object

As we mentioned earlier, @RequestParam accepts the default value using the attribute defaultValue. If the request URI doesn’t contain the query parameter or empty value passed, then the specified default value is used.

If you specify the defaultValue, it implicitly sets the required parameter to false.

For example, the following getOrderStatus controller method gets the isCanceled status as a boolean value. If the request URI doesn’t contain the query parameter isCanceled or empty, then the Spring uses the defaultValue false specified.

@RestController
public class OrdersController {
    Logger logger = (Logger) LoggerFactory.getLogger(OrdersController.class);
    @GetMapping("/orderStatus")
    public String getOrderStatus(@RequestParam(name = "isCanceled",
            defaultValue = "false") Boolean isCanceled) {
        logger.debug("Order isCanceled " + isCanceled);
        return "Order isCancelled: " + isCanceled;
    }
}

When you hit the URI http://localhost:8080/orderStatus, then the above isCanceled Boolean object contains the value false instead of the value null.

If you execute the above code, the following result appears in the console.

Order isCanceled false

3.1. RequestParam value for primitive boolean

You can also use the primitive boolean type for @RequestParam in place of Boolean. In this case, Spring automatically assigns false.

For example, the following isCanceled param is optional.

 @GetMapping("/orderStatus")
    public String getOrderStatus(@RequestParam(name = "isCanceled",
            required = false) boolean isCanceled) {
        logger.debug("Order isCanceled " + isCanceled);
        return "Order isCancelled: " + isCanceled;
    }

When you hit the URI http://localhost:8080/orderStatus, then the Spring assigns false to the isCanceled primitive.

If you execute the above code, the following result appears in the console.

Order isCanceled false

4. Conclusion

To sum up, we have learned to set a default value boolean for the Spring RequestParam. You can find the code samples of this article in our GitHub repository.