When the front-end passes data to the back-end, the back-end displays that the obtained data is NULL. How to solve it?

Problem Description: During the development process of using the Ruoyi separate framework, the front-end uses POST request to pass data to the back-end, but the back-end receives a NULL value.

Front-end code:

 //Modify the order status export function updateorderstatus(id,status){
    const data={
        id,
        status
    }
    return request({
        url:"/business/orderinfo/updatestate",
        method:"post",
        data:data
    })
}

Screenshot of front-end request data: (Screenshot of front-end request data should be included here)

Backend code (original code):

 @ApiOperation("Order Management-Modify Order Status")
@ApiImplicitParams({
    @ApiImplicitParam(name="id", value = "primary key id", required = true, dataType = "integer"),
    @ApiImplicitParam(name="status", value = "Status 0 ends with 1", required = true, dataType = "integer")
})
@PostMapping("/updatestate")
public AjaxResult updateState(Integer id, Integer status) {
    System.out.println("Change Order Number: "id "\n");
    System.out.println("Change order status: " status "\n");
    // ... (Other code)
}

Screenshot of backend printing results: (This should include screenshots of backend printing results, showing id and status as null)

Problem analysis: The backend uses Integer id, Integer status to receive parameters. When processing POST requests, Spring Boot cannot correctly parse JSON data in the request body to these parameters by default.

Solution: Modify the backend code and bind the JSON data in the request body to an object using the @RequestBody annotation.

Modified backend code:

 @ApiOperation("Order Management-Modify Order Status")
@PostMapping("/updatestate")
public AjaxResult updateState(@RequestBody OrderStatusDTO orderStatusDTO) {
    System.out.println("Change Order Number:" orderStatusDTO.getId() "\n");
    System.out.println("Change order status:" orderStatusDTO.getStatus() "\n");

    if (orderStatusDTO.getId() == null) {
        return AjaxResult.error("enter primary key id");
    }
    if (orderStatusDTO.getStatus() == null) {
        return AjaxResult.error("Input Status");
    }

    BorderInfo borderInfo = new BorderInfo();
    borderInfo.setId(orderStatusDTO.getId());
    borderInfo.setStatus(orderStatusDTO.getStatus());
    System.out.println("Change order status:" borderInfo.toString() "\n");
    orderInfoService.update(borderInfo);
    return AjaxResult.success();
}

Added OrderStatusDTO class:

 public class OrderStatusDTO {
    private Integer id;
    private Integer status;

    // getters and setters
}

By using @RequestBody annotation and creating an OrderStatusDTO class to receive the JSON data passed by the front end, the backend can correctly parse the data to avoid the problem of NULL values. Please make sure that the JSON data sent by the front end is consistent with the field name of OrderStatusDTO . At the same time, check whether the front-end request function has correctly set headers , such as Content-Type: application/json .

This solution is more in line with the design specifications of the RESTful API than the original @RequestParam solution, and also processes the body data of POST requests more clearly.

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