Spring Data Jpa Set Return Type

Set interface is defined in java Collection framework. Set doesn't contains duplicate elements. Set elements cannot be accessed using integer index.

drop database if exists AppleDb;
create database AppleDb;
use AppleDb;
create TABLE apple ( apple_id BIGINT NOT NULL, apple_name VARCHAR(255) DEFAULT NULL,rating int(1) DEFAULT NULL, PRIMARY KEY (apple_id)) ENGINE=INNODB;
create TABLE hibernate_sequence ( next_val BIGINT) ENGINE=INNODB;

insert into hibernate_sequence values ( 1 );
insert into apple (apple_id, apple_name, taste) values (1, "Macintosh", "tangy");
insert into apple (apple_id, apple_name, taste) values (2, "Macintosh", "tangy");
insert into apple (apple_id, apple_name, taste) values (3, "Macintosh", "sweet");
insert into apple (apple_id, apple_name, taste) values (4, "Macintosh", "sweet");
insert into apple (apple_id, apple_name, taste) values (5, "Macintosh", "juicy");
insert into apple (apple_id, apple_name, taste) values (6, "Macintosh", "juicy");
insert into apple (apple_id, apple_name, taste) values (7, "Macintosh", "tart");
insert into apple (apple_id, apple_name, taste) values (8, "Macintosh", "tart");

package com.sujan.example.jpa.controller;

import com.sujan.example.jpa.entity.Apple;
import com.sujan.example.jpa.repository.AppleRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.Set;

@RestController
public class AppleController {
    @Autowired
    private AppleRepository appleRepository;

    @GetMapping
    Set<Apple> findAll() {
        Set<Apple> apple = appleRepository.findByAppleName("Macintosh");
        apple.forEach(System.out::println);
        return apple;
    }
}

package com.sujan.example.jpa.entity;

import lombok.Data;
import lombok.NoArgsConstructor;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import java.util.Objects;

@Data
@Entity
@NoArgsConstructor
public class Apple {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long appleId;
    private String appleName;
    private String taste;

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        Apple apple = (Apple) o;
        return Objects.equals(appleName, apple.appleName) &&
                Objects.equals(taste, apple.taste);
    }

    @Override
    public int hashCode() {
        return Objects.hash(appleName, taste);
    }
}

package com.sujan.example.jpa.repository;

import com.sujan.example.jpa.entity.Apple;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;

import java.util.Set;

@Repository
public interface AppleRepository extends JpaRepository<Apple, Long> {
    Set<Apple> findByAppleName(String appleName);
}

package com.sujan.example.jpa;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class JpaApplication {
    public static void main(String[] args) {
        SpringApplication.run(JpaApplication.class, args);
    }
}

spring.datasource.url=jdbc:mysql://localhost:3306/AppleDb
spring.datasource.username=root
spring.datasource.password=root

plugins {
    id 'org.springframework.boot' version '2.3.3.RELEASE'
    id 'io.spring.dependency-management' version '1.0.10.RELEASE'
    id 'java'
}
group = 'com.sujan'
version = '0.0.1-SNAPSHOT'
sourceCompatibility = '11'
configurations {
    compileOnly {
        extendsFrom annotationProcessor
    }
}
repositories {
    mavenCentral()
}
dependencies {
    implementation 'org.springframework.boot:spring-boot-starter-web'
    annotationProcessor 'org.projectlombok:lombok'
    compileOnly 'org.projectlombok:lombok'
    implementation 'org.springframework.boot:spring-boot-starter-data-jpa'
    runtimeOnly 'mysql:mysql-connector-java'
    testImplementation('org.springframework.boot:spring-boot-starter-test') {
        exclude group: 'org.junit.vintage', module: 'junit-vintage-engine'
    }
}
test {
    useJUnitPlatform()
}

curl --location --request GET 'http://localhost:8080/'

select apple0_.apple_id as apple_id1_0_, apple0_.apple_name as apple_na2_0_, apple0_.taste as taste3_0_ from apple apple0_ where apple0_.apple_name=?
Apple(appleId=1, appleName=Macintosh, taste=tangy)
Apple(appleId=3, appleName=Macintosh, taste=sweet)
Apple(appleId=5, appleName=Macintosh, taste=juicy)
Apple(appleId=7, appleName=Macintosh, taste=tart)