我正在打印一个类的字段。课程如下：

package com.telstra.sdwan.portal.model.neo4j;

import lombok.Getter;
import lombok.NoArgsConstructor;
import lombok.Setter;
import org.neo4j.ogm.annotation.GeneratedValue;
import org.neo4j.ogm.annotation.Id;
import org.neo4j.ogm.annotation.NodeEntity;

import java.util.HashMap;

@NodeEntity
@Getter
@Setter
@NoArgsConstructor
public class Metrics {

    @Id
    @GeneratedValue
    public Long id;
    public String name;
    public HashMap<String, Long> success = new HashMap<String, Long>();
    public HashMap<String, Long> failure = new HashMap<String, Long>();

    public Metrics(String name) {
        this.name = name;
        success.put(name, 0L);
        failure.put(name, 0L);
    }
}

在 Postman 中运行api时，出现以下错误：

{
    "timestamp": "2021-01-27T16:28:44.5161857",
    "status": "BAD_REQUEST",
    "errors": [
        "Malformed JSON request"
    ],
    "message": "Required request body is missing: public org.springframework.http.ResponseEntity<com.telstra.sdwan.portal.model.neo4j.Metrics> com.telstra.sdwan.portal.controller.ConfigOpsAppController.apiCalled(com.telstra.sdwan.portal.model.neo4j.Metrics)",
    "data": [],
    "path": "/api/configops-app/metrics"
}

控制器方法

@ApiOperation("Count of the number of times an API is called")
@GetMapping(value="/metrics")
@PreAuthorize("hasRole('User')")
public ResponseEntity<Metrics> apiCalled(@RequestBody Metrics metrics){ 
    return configOpsAPIService.apiCount(metrics);
}

请建议如何解决此错误。