java - ResourceController 上的 NumberFormatException 无法从字符串转换为整数

Question

我有一个带有 get 方法的 Controller ，该方法接收 3 个参数作为 java.lang.Integer

@GetMapping(path = Constantes.CONSULTAR_NODO_SUCESOR)
    public ConsultarNodoSucesorResponse consultarNodoSucesor(@RequestHeader HttpHeaders headerRequest,
                                                             @RequestParam(required = false) Integer idArbol, 
                                                             @RequestParam(required = false) Integer nivelFormulario, 
                                                             @RequestParam(required = false) Integer idSucesor,
                                                             @RequestParam(required = false) String rutaRelacion, 
                                                             @RequestParam(required = false) String tipoRelacion, 
                                                             HttpServletResponse headerResponse) {
        ConsultarNodoSucesorRequest request = new ConsultarNodoSucesorRequest(idArbol, nivelFormulario, idSucesor,
                rutaRelacion, tipoRelacion);
        return service.consultarNodoSucesor(headerRequest, request, headerResponse);
    }

当服务器因错误请求而返回代码 400 时，完整错误如下

Failed to convert value of type 'java.lang.String' to required type 'java.lang.Integer'; nested exception is java.lang.NumberFormatException: For input string: \"4111111111\

我在参数 idArbol 中发送值 4111111111，但它不起作用，另一方面，当我发送相同的参数值(如 1044444444)时，它工作正常。

为什么会出现这样的情况呢？ 整数的最大值是多少

Answer 1

与值 1044444444 不同，值 4111111111 对于 int(因此是 Integer)数据来说太大类型，因此被理解为String。该值超出了整数允许的范围。

参见Primitive Data Types :

int: By default, the int data type is a 32-bit signed two's complement integer, which has a minimum value of -231 and a maximum value of 231-1.

你可能想知道为什么 Spring 会有这样的行为。这是Type Conversion Spring的几个注解的特点，其中String是默认值:

Some annotated controller method arguments that represent String-based request input (such as @RequestParam, @RequestHeader, @PathVariable, @MatrixVariable, and @CookieValue) can require type conversion if the argument is declared as something other than String.

For such cases, type conversion is automatically applied based on the configured converters. By default, simple types (int, long, Date, and others) are supported. You can customize type conversion through a WebDataBinder (see DataBinder) or by registering Formatters with the FormattingConversionService. See Spring Field Formatting.