I'm new to spring boot and learning @RequestParam()
I know that we can give defaultValue in String but when I am trying to give default value as Integer it's showing me an error.
@RequestMapping("/returnVeriable")
public int getVeriable(@RequestParam(required=true,defaultValue=1/*error here*/) int veri){
return veri;
}
any help would be appreciated.
Try with "" around integer to make it string as the defaultValue is implemented as String.
@RequestMapping("/returnVeriable")
public int getVeriable(@RequestParam(required=true,defaultValue="1") Integer veri){
return veri;
}
required=true together with defaultValue does not make much sense as defaultValue implicitly sets required to false.
Integer instead of int?
Integer can be null, but int cannot. If for some reason the param is blank, it would seem that they had put 0 instead of null.When a value traffic by HTTP protocol, it has no type. It's a String. And so it is at this parameter type at the annotation. Then, you do something like this:
@RequestParam(required = true, defaultValue = "1") Integer veri
And it will work fine.
This should work
@RequestMapping("/returnVariable")
public int getVariable(@RequestParam(required=true,defaultValue="1") int var) {
return var;
}
By default what ever you pass to the controller is treated as String and converted to respective types. So even default values need to be set as String
String... The conversion from String to the actual type is done by Spring using Converters and PropertyEditors.
String instead of Object isn't even with Spring. It comes from a limitation in Java itself: stackoverflow.com/a/1458556/593146
defaultValueis aStringspecify the default as aStringvalue. That is also what the compiler is telling you.