这个java模型@oneToMany为什么返回的是递归结果？

Z时代
2024-03-14
分类：IT

最近刚学到Java的JPA
我现在有一个customer模型：

package com.example.demo.model.po;
import lombok.Data;
import org.hibernate.annotations.Fetch;
import org.hibernate.annotations.FetchMode;
import javax.persistence.*;
import java.util.HashSet;
import java.util.Set;
@Entity
@Table
@Data
public class Customer {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    @OneToMany(mappedBy = "customer")
    @Fetch(value = FetchMode.SELECT)
    private Set<Order> orders = new HashSet<>();}

一个order

package com.example.demo.model.po;
import lombok.*;
import org.hibernate.Hibernate;
import javax.persistence.*;
import java.util.Objects;
@Entity
@Table(name = "orders")
@Getter
@Setter
@ToString
@RequiredArgsConstructor
public class Order {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    private String name;
    @ManyToOne
    @JoinColumn(name = "customer_id")
    private Customer customer;
    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || Hibernate.getClass(this) != Hibernate.getClass(o)) return false;
        Order order = (Order) o;
        return id != null && Objects.equals(id, order.id);
    }
    @Override
    public int hashCode() {
        return getClass().hashCode();
    }}

控制器使用

package com.example.demo.controller;
import com.example.demo.model.po.Customer;
import com.example.demo.repository.CustomerRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
@RequestMapping("/api/customer")
public class CustomerController {
    @Autowired
    private CustomerRepository repo;
    @GetMapping("/{id}")
    public ResponseEntity<Customer> findById(@PathVariable Long id){
        Customer customer = repo.findById(id).get();
        return ResponseEntity.ok(customer);
    }}

返回的结果像这样：

{ "id": 1, "orders": [ { "id": 1, "name": "ONE", "customer": { "id": 1, "orders": [ { "id": 1, "name": "ONE", "customer": { "id": 1, "orders": [ { "id": 1, "name": "ONE", "customer": { "id": 1, "orders": [ { "id": 1, "name": "ONE", "customer": { "id": 1, "orders": [ //...还有很多层

}

是哪里写的不对吗？请大佬指教，谢谢。