Json, Hibernate, Spring boot

Question

I’m having two situations that should do the same thing but don’t:

package com.example.demo.entity;

import com.fasterxml.jackson.annotation.JsonIdentityInfo;
import com.fasterxml.jackson.annotation.ObjectIdGenerators;
import java.util.ArrayList;
import java.util.List;

@JsonIdentityInfo(
        generator = ObjectIdGenerators.PropertyGenerator.class,
        property = "id",
        scope = A.class)
public class A {

    public Integer id;
    public String name;
    public List<B> bItens = new ArrayList<>();

    public A() {
    }

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

    public Integer getId() {
        return id;
    }

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

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public List<B> getbItens() {
        return bItens;
    }

    public void setbItens(List<B> bItens) {
        this.bItens = bItens;
    }

    @Override
    public String toString() {
        return "A{" + "id=" + id + ", name=" + name + ", bItens=" + bItens + '}';
    }



}


package com.example.demo.entity;

import com.fasterxml.jackson.annotation.JsonIdentityInfo;
import com.fasterxml.jackson.annotation.ObjectIdGenerators;

@JsonIdentityInfo(
        generator = ObjectIdGenerators.PropertyGenerator.class,
        property = "id",
        scope = B.class)
public class B {

    public Integer id;
    public String itemName;
    public A aOwner;

    public B() {
    }

    public B(Integer id, String itemName, A aOwner) {
        this.id = id;
        this.itemName = itemName;
        this.aOwner = aOwner;
    }

    public Integer getId() {
        return id;
    }

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

    public String getItemName() {
        return itemName;
    }

    public void setItemName(String itemName) {
        this.itemName = itemName;
    }

    public A getaOwner() {
        return aOwner;
    }

    public void setaOwner(A aOwner) {
        this.aOwner = aOwner;
    }

    @Override
    public String toString() {
        return "B{" + "id=" + id + ", itemName=" + itemName + ", aOwner=" + aOwner + '}';
    }

}

As you can see we have 2 classes where you have the oneToMany relationship. If I run this code I won’t have any problem:

@Autowired
    private ARepository ar;

@RequestMapping(value = "/teste1", method = RequestMethod.POST, consumes = {MediaType.APPLICATION_JSON_VALUE, MediaType.APPLICATION_JSON_UTF8_VALUE}, produces = MediaType.APPLICATION_JSON_VALUE)
    public ResponseEntity teste1() {
        A a = ar.getOne(1);
        a.getbItens().clear();
        ar.save(a);
        return ResponseEntity.ok().body("");
    }

In other words, it will delete in the database all objects of type B. But if I make this code:

@Autowired
        private ARepository ar;

    @RequestMapping(value = "/teste2", method = RequestMethod.POST, consumes = {MediaType.APPLICATION_JSON_VALUE, MediaType.APPLICATION_JSON_UTF8_VALUE}, produces = MediaType.APPLICATION_JSON_VALUE)
        public ResponseEntity teste2(@RequestBody A a) {
            a.getbItens().clear();
            ar.save(a);
            return ResponseEntity.ok().body("");
        }

It simply ignores delete and does not do the necessary deletions in the database...

{
    "id": 1,
    "name": "dasdsadsa",
    "bItens": [
        {
            "id": 1,
            "itemName": "sdfdsf",
            "aOwner": 1
        },
        {
            "id": 2,
            "itemName": "sdfdsf",
            "aOwner": 1
        },
        {
            "id": 3,
            "itemName": "sdfdsf",
            "aOwner": 1
        },
        {
            "id": 4,
            "itemName": "sdfdsf",
            "aOwner": 1
        }
    ]
}

Follow the json q I send in method 2

Following the logic of method 2, it should delete all items from the list of objects of class B and then save, but analyzing the Hibernate log.. it makes the selects and simply deduces it has nothing different... and it does not make the pins, however if I make any changes in the data like changing the name of class A or the item of class B it makes the updates