如何在 ResponseEntity 中不 return 空值？

Question

我使用 ResponseEntity 到 return 响应 GET“api/v1/name”和 POST“api/v1/name”请求。

我的目标不是 return 以空值响应，例如在 POST “api/v1/name” 请求中，当前响应正文将是：

{
    "id": null,
    "name": "who",
    "newid": "A8C90A53-78F6-4BD6-9628-CBA8FC349C08"
}

我希望它看起来像什么：

{
    "name": "who",
    "newid": "A8C90A53-78F6-4BD6-9628-CBA8FC349C08"
}

在我看来，使用下面这段代码重新创建对象只会降低代码的可读性并且可能会占用更多内存（我不确定，如果我错了请告诉我）：

...
Map<String, String> responseBody = new HashMap<>();
responseBody.put("name", nameModel.getName());
responseBody.put("newid", nameModel.getNewId());

return new ResponseEntity<>(responseBody, HttpStatus.OK);

==== 下面是完整的存储库，如果您想查看更新后的存储库：https://github.com/kidfrom/g2_java/tree/main/etc/mssqlserver

controller/NameController.java

package com.example.mssqlserver.controller;

import com.example.mssqlserver.mapper.NameMapper;
import com.example.mssqlserver.model.NameModel;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;

@RestController
public class NameController {

  @Autowired
  private NameMapper nameMapper;

  @GetMapping("api/v1/name")
  public ResponseEntity<?> selectAll() {
    return new ResponseEntity<>(nameMapper.selectAll(), HttpStatus.OK);
  }

  @PostMapping("api/v1/name")
  public ResponseEntity<?> insert(@RequestBody NameModel nameModel) {

    // validator
    if (!nameModel.requestIsValid()) {
      return ResponseEntity.badRequest().build();
    }

    if (nameMapper.insert(nameModel) == 1) {
      return new ResponseEntity<>(nameModel, HttpStatus.OK);
    } else {
      return ResponseEntity.badRequest().build();
    }
  }
}

mapper/NameMapper.java

package com.example.mssqlserver.mapper;

import com.example.mssqlserver.model.NameModel;
import org.apache.ibatis.annotations.*;

import java.util.List;

@Mapper
public interface NameMapper {

  @Select("SELECT * FROM name")
  public List<NameModel> selectAll();

  @SelectKey(statement = "SELECT NEWID()", keyProperty = "newid", resultType = String.class, before = true)
  @Insert("INSERT INTO name (name, newid) VALUES (#{name}, #{newid})")
//  @Options(useGeneratedKeys = true, keyProperty = "id")
  int insert(NameModel nameModel);
}

model/NameModel.java

package com.example.mssqlserver.model;

public class NameModel {
  private Integer id;
  private String name;
  private String newid;

  public NameModel(Integer id, String name, String newid) {
    this.id = id;
    this.name = name;
    this.newid = newid;
  }

  public Integer getId() {
    return id;
  }

  public void setId(Integer id) {
    this.id = id;
  }

  public String getName() {
    return name;
  }

  public String getNewid() {
    return newid;
  }

  public void setNewid(String newid) {
    this.newid = newid;
  }

  public boolean requestIsValid() {
    if (this.name.isEmpty()) return false;

    return true;
  }
}

Answer 1

我认为这个简单的解决方案可以帮助您

由于正在使用 Jackson，您必须将其配置为 Jackson 属性。对于Spring Boot REST services，你必须在application.properties或application.yml中配置它：

spring.jackson.default-property-inclusion = NON_NULL

Answer 2

在spring启动视图中https://docs.spring.io/spring-boot/docs/2.4.0/reference/htmlsingle 并搜索 spring.jackson.default-property-inclusion

如何在 ResponseEntity 中不 return 空值？

How to not return null value in ResponseEntity?

java

spring

mybatis

spring-boot