java - 具有多对一关系的无限递归错误

因此，我们尝试设置数据库已多次遇到此问题。基本上，我们有一个联赛，其中会有多个比赛。每当我们尝试打印http://localhost:8080/api/leagues时，页面就会填充无限的联赛列表，然后出现此错误。

“无法呈现请求[/ api / leagues]和异常[无法编写JSON：无限递归（StackOverflowError）的错误页面；嵌套的异常是com.fasterxml.jackson.databind.JsonMappingException：无限递归（StackOverflowError）（通过参考链： org.hibernate.collection.internal.PersistentBag [0]-> com.dontfeed.Dont.Feed.model.League [“ teams]-> org.hibernate.collection.internal.PersistentBag [0]-> com.dontfeed。 Dont.Feed.model.Team [“联盟”]-“

有谁对我们如何解决这个问题有任何想法？
@JsonIgnoreProperties在那里，因为我试图进行故障排除。我可以拿出来。

import com.dontfeed.Dont.Feed.model.enumerator.LeagueFormat;
import com.fasterxml.jackson.annotation.JsonBackReference;
import com.fasterxml.jackson.annotation.JsonIgnore;
import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
import lombok.Data;
import lombok.NoArgsConstructor;

import javax.persistence.*;
import javax.validation.constraints.NotNull;

import java.time.LocalDate;
import java.util.List;

@Data
@Entity
@NoArgsConstructor
@Table(name = "leagues")
public class League {

    @Id
    @NotNull
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id", updatable = false, nullable = false)
    private long id;

    private LocalDate dateCreated;

    private int duration;

    private LocalDate endDate;

    @Enumerated(EnumType.STRING)
    private LeagueFormat format;

    private String logo;

    private String matchFrequency;

    private int maxTeams;

    @Column(unique = true)
    private String name;

    private String description;

    private LocalDate startDate;

    private String passcode;

    // Relationships
    @JsonIgnoreProperties({"hibernateLazyInitializer", "handler"})
    @OneToOne(fetch = FetchType.LAZY)
    private Game game;

    @JsonIgnoreProperties({"hibernateLazyInitializer", "handler"})
    @OneToOne(fetch = FetchType.LAZY)
    private Tournament tournament;

    @JsonIgnoreProperties({"hibernateLazyInitializer", "handler"})
    @OneToMany(fetch = FetchType.LAZY)
    private List<Match> matches;

    @JsonIgnoreProperties({"hibernateLazyInitializer", "handler"})
    @ManyToMany(mappedBy = "leagues", fetch = FetchType.LAZY)
    private List<Team> teams;

    @Override
    public String toString() {
        return "League{" +
                "id=" + id +
                ", dateCreated=" + dateCreated +
                ", duration=" + duration +
                ", endDate=" + endDate +
                ", format=" + format +
                ", logo='" + logo + '\'' +
                ", matchFrequency='" + matchFrequency + '\'' +
                ", maxTeams=" + maxTeams +
                ", name='" + name + '\'' +
                ", startDate=" + startDate +
                ", description= " + description +
                '}';
    }
}

import com.fasterxml.jackson.annotation.JsonIgnore;
import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
import com.fasterxml.jackson.annotation.JsonManagedReference;
import lombok.Data;
import lombok.NoArgsConstructor;

import javax.persistence.*;
import javax.validation.constraints.NotNull;

import java.time.LocalDate;
import java.util.List;

@Data
@Entity
@NoArgsConstructor
@Table(name = "matches")
public class Match {

    @Id
    @NotNull
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id", updatable = false, nullable = false)
    private long id;

    private float duration;

    private LocalDate matchDate;

    private long matchId;

    private String score;

    // Relationships
    @JsonIgnoreProperties({"hibernateLazyInitializer", "handler"})
    @ManyToOne(fetch = FetchType.LAZY)
    private Game game;

    @JsonIgnoreProperties({"hibernateLazyInitializer", "handler"})
    @ManyToOne(fetch = FetchType.LAZY)
    private League league;

    @JsonIgnoreProperties({"hibernateLazyInitializer", "handler"})
    @ManyToOne(fetch = FetchType.LAZY)
    private Team team_a;

    @JsonIgnoreProperties({"hibernateLazyInitializer", "handler"})
    @ManyToOne(fetch = FetchType.LAZY)
    private Team team_b;

    @JsonIgnoreProperties({"hibernateLazyInitializer", "handler"})
    @ManyToOne(fetch = FetchType.LAZY)
    private Team victor;

    @JsonIgnoreProperties({"hibernateLazyInitializer", "handler"})
    @ManyToOne(fetch = FetchType.LAZY)
    private Tournament tournament;

    @Override
    public String toString() {
        return "Match{" +
                "id=" + id +
                ", duration=" + duration +
                ", matchDate=" + matchDate +
                ", matchId=" + matchId +
                ", score='" + score + '\'' +
                ", victor=" + victor +
                '}';
    }
}

import com.dontfeed.Dont.Feed.model.League;
import com.dontfeed.Dont.Feed.service.LeagueService;
import lombok.AllArgsConstructor;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;

@RestController
@AllArgsConstructor
@CrossOrigin(origins = "http://localhost:3000")
@RequestMapping(value = LeagueController.PATH, produces = MediaType.APPLICATION_JSON_VALUE)
public class LeagueController {

    static final String PATH = "/api/leagues";
    private final LeagueService leagueService;

    @GetMapping
    public ResponseEntity<?> getLeagues() {
        System.out.println("Test");
        if (leagueService.findAllLeagues() == null) {
            return ResponseEntity
                    .status(HttpStatus.BAD_REQUEST)
                    .body("No results found");
        }
        return ResponseEntity
                .status(HttpStatus.OK)
                .body(leagueService.findAllLeagues());
    }

最佳答案

从错误看来，您已将Team内的League和League内的Team映射了。
它开始转换为JSON的周期。

将@JsonIgnore与League内的Team一起使用。