請求有效負載內的字段在Spring Boot資源中顯示為null

Question

我有以下類別，將其用作請求有效負載：

public class SampleRequest {

    private String fromDate;
    private String toDate;

    // Getters and setters removed for brevity.
}

我正在嘗試使用下面的資源（只是嘗試將其打印到屏幕上以查看發生的事情）：

@PostMapping("/getBySignatureOne")
public ResponseEntity<?> getRequestInfo(@Valid @RequestBody SampleRequest sampleRequest) {
    System.out.println(sampleRequest.getToDate());
    System.out.println(sampleRequest.getFromDate());
}

這是我發送的JSON請求：

{
    "fromDate":"2019-03-09",
    "toDate":"2019-03-10"
}

println的輸出是：

null
null

我需要做些什么來連接嗎？

Answer 1

請在以下配置中找到相同的代碼

Spring-Boot版本：2.1.3

調節器

package com.firsttest.controller;

import javax.validation.Valid;

import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import com.firsttest.pojo.SampleRequest;

@RestController
@RequestMapping("/test")
public class FirstTestController {



    @PostMapping("/getBySignatureOne")
    public ResponseEntity<?> getTestString(@Valid @RequestBody SampleRequest sampleRequest) {
        System.out.println("getFromDate : " + sampleRequest.getFromDate());
        System.out.println("getToDate : " + sampleRequest.getToDate());
        return null;//I dont want to send any response.
    }
}

SampleRequest.java

package com.firsttest.pojo;

public class SampleRequest {

    private String fromDate;
    private String toDate;

    public String getFromDate() {
        return fromDate;
    }
    public void setFromDate(String fromDate) {
        this.fromDate = fromDate;
    }
    public String getToDate() {
        return toDate;
    }
    public void setToDate(String toDate) {
        this.toDate = toDate;
    }

}

請求

http://localhost:8080/first/test/getBySignatureOne
httpmethod: POST
Content-Type:application/json
{
    "fromDate":"2019-03-09",
    "toDate":"2019-03-10"
}

輸出是

getFromDate : 2019-03-09
getToDate : 2019-03-10