Question

我使用spring-boot来提供与MongoDB持久存在的REST接口。我正在使用＆＃39;标准＆＃39;依赖性来支持它，包括spring-boot-starter-data-mongodb和spring-boot-starter-web。

但是，在我的一些类中，我有一些注释@Transient的字段，以便MongoDB不会保留该信息。但是，我希望这些信息在我的休息服务中发送出去。不幸的是，MongoDB和其他控制器似乎都共享该注释。因此，当我的前端收到JSON对象时，这些字段不会被实例化（但仍然被声明）。删除注释允许字段在JSON对象中通过。

我如何分别为MongoDB和REST配置瞬态？

这是我的班级

package com.clashalytics.domain.building;

import com.clashalytics.domain.building.constants.BuildingConstants;
import com.clashalytics.domain.building.constants.BuildingType;
import com.google.common.base.Objects;
import org.springframework.data.annotation.Id;
import org.springframework.data.annotation.Transient;

import java.util.*;

public class Building {

    @Id
    private int id;

    private BuildingType buildingType;
    private int level;
    private Location location;
    // TODO http://stackoverflow.com/questions/30970717/specify-field-is-transient-for-mongodb-but-not-for-restcontroller
    @Transient
    private int hp;
    @Transient
    private BuildingDefense defenses;

    private static Map<Building,Building> buildings = new HashMap<>();

    public Building(){}
    public Building(BuildingType buildingType, int level){
        this.buildingType = buildingType;
        this.level = level;
        if(BuildingConstants.hpMap.containsKey(buildingType))
            this.hp = BuildingConstants.hpMap.get(buildingType).get(level - 1);

        this.defenses = BuildingDefense.get(buildingType, level);
    }

    public static Building get(BuildingType townHall, int level) {
        Building newCandidate = new Building(townHall,level);
        if (buildings.containsKey(newCandidate)){
            return buildings.get(newCandidate);
        }
        buildings.put(newCandidate,newCandidate);
        return newCandidate;
    }

    public int getId() {
        return id;
    }

    public String getName(){
        return buildingType.getName();
    }

    public BuildingType getBuildingType() {
        return buildingType;
    }

    public int getHp() {
        return hp;
    }

    public int getLevel() {
        return level;
    }

    public Location getLocation() {
        return location;
    }

    public void setLocation(Location location) {
        this.location = location;
    }

    public BuildingDefense getDefenses() {
        return defenses;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        Building building = (Building) o;
        return Objects.equal(id, building.id) &&
                Objects.equal(hp, building.hp) &&
                Objects.equal(level, building.level) &&
                Objects.equal(buildingType, building.buildingType) &&
                Objects.equal(defenses, building.defenses) &&
                Objects.equal(location, building.location);
    }

    @Override
    public int hashCode() {
        return Objects.hashCode(id, buildingType, hp, level, defenses, location);
    }
}

原样，hp和defenses分别显示为0和null。如果我删除@Transient标记，则会显示。

Answer 1

只要您使用org.springframework.data.annotation.Transient，它就应该按预期工作。杰克逊对 spring-data 一无所知，它忽略了它的注释。

示例代码，有效：

interface PersonRepository extends CrudRepository<Person, String> {}

import org.springframework.data.annotation.Id;
import org.springframework.data.annotation.Transient;
import org.springframework.data.mongodb.core.mapping.Document;

@Document
class Person {
    @Id
    private String id;
    private String name;
    @Transient
    private Integer age;

    // setters & getters & toString()
}

@RestController
@RequestMapping("/person")
class PersonController {
    private static final Logger LOG = LoggerFactory.getLogger(PersonController.class);
    private final PersonRepository personRepository;

    @Autowired
    PersonController(PersonRepository personRepository) {
        this.personRepository = personRepository;
    }

    @RequestMapping(method = RequestMethod.POST)
    public void post(@RequestBody Person person) {
        // logging to show that json deserialization works
        LOG.info("Saving person: {}", person);
        personRepository.save(person);
    }

    @RequestMapping(method = RequestMethod.GET)
    public Iterable<Person> list() {
        Iterable<Person> list = personRepository.findAll();
        // setting age to show that json serialization works
        list.forEach(foobar -> foobar.setAge(18));

        return list;
    }
}

执行 POST http://localhost:8080/person：

{
    "name":"John Doe",
    "age": 40
}

记录输出Saving person: Person{age=40, id='null', name='John Doe'}
person集合中的条目： { "_id" : ObjectId("55886dae5ca42c52f22a9af3"), "_class" : "demo.Person", "name" : "John Doe" } - 年龄未持久

执行 GET http://localhost:8080/person：

结果：[{"id":"55886dae5ca42c52f22a9af3","name":"John Doe","age":18}]

Answer 2

你的问题似乎是mongo和jackson都表现得像预期的那样。 Mongo不会保留数据，而jackson会忽略该属性，因为它被标记为瞬态。我设法通过＆＃39;欺骗＆＃39; jackson忽略瞬态字段，然后用@JsonProperty注释getter方法。这是我的样本bean。

    @Entity
    public class User {

    @Id
    private Integer id;
    @Column
    private String username;

    @JsonIgnore
    @Transient
    private String password;

    @JsonProperty("password")
    public String getPassword() {
        return // your logic here;
    }
}

这不仅仅是一个合适的解决方案，所以我不确定这是否会为您带来任何副作用。

Answer 3

卡洛斯-bribiescas，你用的是什么版本的。它可能是版本问题。因为这个瞬态注释只是为了不坚持到mongo db。请尝试更改版本。可能类似于Maciej one（1.2.4版本）

在其中一个版本中，有一个json解析spring数据项目的问题。 http://www.widecodes.com/CyVjgkqPXX/fields-with-jsonproperty-are-ignored-on-deserialization-in-spring-boot-spring-data-rest.html

Answer 4

由于您没有将MongoRepositories作为具有Spring Data REST的平静端点公开，因此让您的Resources/endpoint响应与您的域模型分离更有意义，这样您的域模型就可以在没有影响您的其他客户/消费者。对于资源，您可以考虑利用Spring HATEOAS提供的内容。

Answer 5

我使用 @JsonSerialize 解决了这个问题。如果您希望将其除去，也可以选择 @JsonDeserialize 。

@Entity
public class Article {

@Column(name = "title")
private String title;

@Transient
@JsonSerialize
@JsonDeserialize
private Boolean testing;
}

// No annotations needed here
public Boolean getTesting() {
    return testing;
}

public void setTesting(Boolean testing) {
    this.testing = testing;
}

Answer 6

我通过实现自定义JacksonAnnotationIntrospector解决了这个问题：

@Bean
@Primary
ObjectMapper objectMapper() {
  Jackson2ObjectMapperBuilder builder = new Jackson2ObjectMapperBuilder();
  AnnotationIntrospector annotationIntrospector = new JacksonAnnotationIntrospector() {
    @Override
    protected boolean _isIgnorable(Annotated a) {
      boolean ignorable = super._isIgnorable(a);
      if (ignorable) {
        Transient aTransient = a.getAnnotation(Transient.class);
        JsonIgnore jsonIgnore = a.getAnnotation(JsonIgnore.class);

        return aTransient == null || jsonIgnore != null && jsonIgnore.value();
      }
      return false;
    }
  };
  builder.annotationIntrospector(annotationIntrospector);
  return builder.build();
}

此代码对org.springframework.data.annotation.Transient进行了不可见的Jackson注释，但对mongodb有效。

对于MongoDB，指定字段是瞬态的，但对于RestController则不是

6 个答案: