尝试将我的类转换为 Json 时出现 stackoverflow 错误 [重复]

【问题标题】：I get stackoverflow error when trying to convert my class to Json [duplicate]尝试将我的类转换为 Json 时出现 stackoverflow 错误 [重复]
【发布时间】：2018-07-24 15:16:49
【问题描述】：

我正在尝试将从数据库收到的列表对象转换为 Json，但是当我尝试转换时得到了。

java.lang.StackOverflowError: null
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.write(ReflectiveTypeAdapterFactory.java:243) ~[gson-2.8.0.jar:na]
at com.google.gson.Gson$FutureTypeAdapter.write(Gson.java:976) ~[gson-2.8.0.jar:na]
at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:69) ~[gson-2.8.0.jar:na]
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.write(ReflectiveTypeAdapterFactory.java:125) ~[gson-2.8.0.jar:na]
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.write(ReflectiveTypeAdapterFactory.java:243) ~[gson-2.8.0.jar:na]
at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:69) ~[gson-2.8.0.jar:na]
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.write(ReflectiveTypeAdapterFactory.java:125) ~[gson-2.8.0.jar:na]
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.write(ReflectiveTypeAdapterFactory.java:243) ~[gson-2.8.0.jar:na]
at com.google.gson.Gson$FutureTypeAdapter.write(Gson.java:976) ~[gson-2.8.0.jar:na]
at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:69) ~[gson-2.8.0.jar:na]
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.write(ReflectiveTypeAdapterFactory.java:125) ~[gson-2.8.0.jar:na]
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.write(ReflectiveTypeAdapterFactory.java:243) ~[gson-2.8.0.jar:na]
at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:69) ~[gson-2.8.0.jar:na]
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.write(ReflectiveTypeAdapterFactory.java:125) ~[gson-2.8.0.jar:na]
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.write(ReflectiveTypeAdapterFactory.java:243) ~[gson-2.8.0.jar:na]
at com.google.gson.Gson$FutureTypeAdapter.write(Gson.java:976) ~[gson-2.8.0.jar:na]
at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:69) ~[gson-2.8.0.jar:na]
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.write(ReflectiveTypeAdapterFactory.java:125) ~[gson-2.8.0.jar:na]
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.write(ReflectiveTypeAdapterFactory.java:243) ~[gson-2.8.0.jar:na]
at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:69) ~[gson-2.8.0.jar:na]
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.write(ReflectiveTypeAdapterFactory.java:125) ~[gson-2.8.0.jar:na]
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.write(ReflectiveTypeAdapterFactory.java:243) ~[gson-2.8.0.jar:na]
at com.google.gson.Gson$FutureTypeAdapter.write(Gson.java:976) ~[gson-2.8.0.jar:na]
at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:69) ~[gson-2.8.0.jar:na]
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.write(ReflectiveTypeAdapterFactory.java:125) ~[gson-2.8.0.jar:na]
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.write(ReflectiveTypeAdapterFactory.java:243) ~[gson-2.8.0.jar:na]
at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:69) ~[gson-2.8.0.jar:na]
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.write(ReflectiveTypeAdapterFactory.java:125) ~[gson-2.8.0.jar:na]
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.write(ReflectiveTypeAdapterFactory.java:243) ~[gson-2.8.0.jar:na]
at com.google.gson.Gson$FutureTypeAdapter.write(Gson.java:976) ~[gson-2.8.0.jar:na]
at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:69) ~[gson-2.8.0.jar:na]
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.write(ReflectiveTypeAdapterFactory.java:125) ~[gson-2.8.0.jar:na]
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.write(ReflectiveTypeAdapterFactory.java:243) ~[gson-2.8.0.jar:na]
at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:69) ~[gson-2.8.0.jar:na]
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.write(ReflectiveTypeAdapterFactory.java:125) ~[gson-2.8.0.jar:na]
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.write(ReflectiveTypeAdapterFactory.java:243) ~[gson-2.8.0.jar:na]
at com.google.gson.Gson$FutureTypeAdapter.write(Gson.java:976) ~[gson-2.8.0.jar:na]
at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:69) ~[gson-2.8.0.jar:na]
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.write(ReflectiveTypeAdapterFactory.java:125) ~[gson-2.8.0.jar:na]
at (and so on)

这是我的代码：

@RequestMapping(value = "/query/orders",method = RequestMethod.GET)
public String QueryOrderTable(HttpServletRequest request){

    DataTableRequest<Orders> dataTableInRQ = new DataTableRequest<Orders>(request);
    PaginationCriteria pagination = dataTableInRQ.getPaginationRequest();

    String baseQuery = "SELECT id as id, time as time, amount as amount, status as status, style as style, fashionbrand as fashionbrand, user_id as user_id, (SELECT COUNT(1) FROM ORDERS) AS totalrecords  FROM ORDERS";
    String paginatedQuery = AppUtil.buildPaginatedQuery(baseQuery, pagination);

    System.out.println(paginatedQuery);

    Query query = entityManager.createNativeQuery(paginatedQuery, Orders.class);

    @SuppressWarnings("unchecked")
    List<Orders> ordersList = query.getResultList();

    DataTableResults<Orders> dataTableResult = new DataTableResults<Orders>();
    dataTableResult.setDraw(dataTableInRQ.getDraw());
    dataTableResult.setListOfDataObjects(ordersList);
    if (!AppUtil.isObjectEmpty(ordersList)) {
        dataTableResult.setRecordsTotal(String.valueOf(ordersList.size())
        );
        if (dataTableInRQ.getPaginationRequest().isFilterByEmpty()) {
            dataTableResult.setRecordsFiltered(String.valueOf(ordersList.size()));
        } else {
            dataTableResult.setRecordsFiltered(String.valueOf(ordersList.size()));
        }
    }
    JSONSerializer serializer = new JSONSerializer();

    return serializer.deepSerialize(dataTableResult);
}

我的想法是我从数据库中检索 Orderobjects 列表，将其传递给 dataTableResult 并将其发送到前端以由 Jquerydatatable 显示，我得到了列表，但是当我尝试使用 GSON() 来尝试转换 orederList 或 dataTableResult 它会引发错误。我切换到 flexJson，它允许我将 orderList 转换为 json 但不是 dataTableResult。请有人解释一下为什么会这样。

这分别是我的 Order 类和 dataTableResult 类：

@Entity
public class Orders extends DefaultEntity {

  @Expose(serialize = false)
  @ManyToOne
  @JoinColumn(name = "fashionbrand")
  private FashionBrand fashionBrand;

  private double amount;

  @Enumerated(EnumType.STRING)
  @Column(name = "style")
  private Enum.ClothStyle clothStyle;

  @Expose(serialize = false)
  @OneToMany
  private List<ClothModel> clothModels = new ArrayList<>();

  @Enumerated(EnumType.STRING)
  private Enum.Status status;

  @Expose(serialize = false)
  @ManyToOne
  @JoinColumn(name = "user_id")
  private User user;
}

public class DataTableResults<T> {

  /** The draw. */
  private String draw;

  /** The records filtered. */
  private String recordsFiltered;

  /** The records total. */
  private String recordsTotal;

  /** The list of data objects. */
  @SerializedName("data")
  List<T> listOfDataObjects;    
}

这是 ClothModel 类：

@Entity
public class ClothModel extends DefaultEntity {

    private int quantity;

    private double amount;

    @Transient
    private String modelStructure;

    private String savedUrl;
}

FashionBrand 类：

@Entity
public class FashionBrand extends DefaultEntity {

    private String brandName;

    private String image;

    private String website;

    @Email
    private String email;

    private String password;

    private String phoneNumber;

    private String brandPhrase;

    @JsonIgnore
    @Transient
    private List<Rating> ratings = new ArrayList<>();

    private String location;

    @OneToOne(cascade = CascadeType.ALL, fetch = FetchType.EAGER)
    @JoinColumn(name = "pricing_id")
    private Pricing pricing;


    @OneToOne(cascade = CascadeType.ALL, fetch = FetchType.EAGER)
    @JoinColumn(name = "services_id")
    private Services services;

    @JsonIgnore
    @Transient
    private List<Orders> orders = new ArrayList<>();

    @JsonIgnore
    @Transient
    private List<Employee> employees = new ArrayList<>();
}

最后是默认实体类：

@MappedSuperclass
public class DefaultEntity implements Serializable {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(columnDefinition = "serial")
    private long id;

    @Column(name = "Time",columnDefinition= "TIMESTAMP WITH TIME ZONE")
    @Temporal(TemporalType.TIMESTAMP)
    private Date dateCreated;

    public long getId() {
        return id;
    }

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

    public Date getDateCreated() {
        return dateCreated;
    }

    public void setDateCreated() {

        SimpleDateFormat dateFormat = new SimpleDateFormat("dd-MM-yyyy HH:mm:ss");

        dateFormat.setTimeZone(TimeZone.getTimeZone("UTC"));

        try {
            dateCreated = dateFormat.parse(dateFormat.format(new Date()));
        } catch (ParseException e) {
            e.printStackTrace();
        }
    }
}

【问题讨论】：

  • 你的标题错了吗？错误不匹配。
  • 您提供的堆栈跟踪的 sn-p 描述性不足以确定实际原因是什么。在编组过程中闻起来像是一个错误，但我不完全确定，因为您删除了讨论您的代码的堆栈跟踪部分。
  • 当你有循环引用时会发生这种情况。您的“ClothModel”是否引用了“Orders”类。
  • @Keaz 我没有
  • @Thanus 能否提供完整的代码，以便我们更好地了解关系。

标签： java gson flexjson


【解决方案1】：

这很可能是因为您在 Orders 类中引用了 FashionBrand，并且在 FashionBrand 类中引用了 Order。在生成 JSON 时，它们会不断地相互引用，从而导致 stackoverflow。我意识到 FashionBrand 的字段上有一个 @JsonIgnore 注释，但我仍然会说这个注释可能被忽略了。据我所知，这是一个 Jackson 注释，但您似乎使用的是 Google 的 GSON，它不会关心该注释。调试起来应该很容易。

在您的 Orders 类中：

@Expose(serialize = false)
@ManyToOne
@JoinColumn(name = "fashionbrand")
private FashionBrand fashionBrand;

在您的 FashionBrand 类中：

@JsonIgnore
@Transient
private List<Orders> orders = new ArrayList<>();

【讨论】：

    猜你喜欢
    • 1970-01-01
    • 1970-01-01
    • 2021-10-03
    • 1970-01-01
    • 1970-01-01
    • 1970-01-01
    • 2022-09-22
    • 1970-01-01
    • 1970-01-01
    相关资源
    最近更新 更多
    热门标签
    Java Python linux javascript Mysql C# Docker 算法 前端 SpringBoot Redis Vue spring 设计模式 .net core .net kubernetes c++ 数据库 数据结构 大数据 js 机器学习 微服务 Android Go 程序员 面试 JVM ASP.net core 云原生 人工智能 后端 PHP git CSS golang k8s Nginx Django mybatis 深度学习 多线程 React 架构 devops 爬虫 云计算 Spring Boot LeetCode