java 如何在@RequestParam() 中将默认值设为整数
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How to give default value as integer in @RequestParam()
提问by Siddhesh
I'm new to spring bootand learning @RequestParam()
我是Spring Boot和学习的新手@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.
我知道我们可以在 String 中提供 defaultValue 但是当我尝试将默认值提供为 Integer 时，它向我显示了一个错误。
@RequestMapping("/returnVeriable")
public int getVeriable(@RequestParam(required=true,defaultValue=1/*error here*/) int veri){
return veri;
}
any help would be appreciated.
任何帮助，将不胜感激。
回答by Ajay Dsouza
Try with "" around integer to make it string as the defaultValue is implemented as String.
尝试在整数周围使用 "" 使其成为字符串，因为 defaultValue 是作为字符串实现的。
@RequestMapping("/returnVeriable")
public int getVeriable(@RequestParam(required=true,defaultValue="1") Integer veri){
return veri;
}
回答by Fabiano Oliveira
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:
当一个值流量通过 HTTP 协议时，它没有类型。它是一个字符串。所以它是在注释处的这个参数类型。然后，你做这样的事情：
@RequestParam(required = true, defaultValue = "1") Integer veri
@RequestParam(required = true, defaultValue = "1") Integer veri
And it will work fine.
它会正常工作。
回答by pvpkiran
This should work
这应该工作
@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
默认情况下，您传递给控制器的任何内容都被视为字符串并转换为相应的类型。所以即使是默认值也需要设置为 String
