我尝试在我的实体中实现映射（Map），但我不知道如何做：
``` java
public class Match {
    private Long id;
    @Builder.Default
    @ManyToMany(targetEntity = Coupon.class,
            mappedBy = "matchList")
    private List<Coupon> couponList = new ArrayList<>();
}

public class Coupon {
    private Long id;
    @ManyToMany
    @JoinTable(
            name = "JOIN_MATCH_ID",
            joinColumns = {@JoinColumn(name = "MATCH_ID", referencedColumnName = "ID")},
            inverseJoinColumns = {@JoinColumn(name = "COUPON_ID", referencedColumnName = "ID")})
    private Map<Match, Integer> mapList = new HashMap<>();

<details>
<summary>英文:</summary>
I try to implement map in my entity but I don&#39;t know how:
``` java
public class Match {
private Long id;
    @Builder.Default
    @ManyToMany(targetEntity = Coupon.class,
            mappedBy = &quot;matchList&quot;)
    private List&lt;Coupon&gt; couponList = new ArrayList&lt;&gt;();
}

public class Coupon {
private Long id;
    @ManyToMany
    @JoinTable(
            name = "JOIN_MATCH_ID",
            joinColumns = {@JoinColumn(name = "MATCH_ID", referencedColumnName = "ID")},
            inverseJoinColumns = {@JoinColumn(name = "COUPON_ID", referencedColumnName = "ID")})
    private Map<Match, Integer> mapList = new HashMap<>();

create table TST_MATCH
(
   mt_id int not null,
   primary key (mt_id)
);
create table TST_COUPON
(
   cn_id int not null,
   primary key (cn_id)
);
create table TST_MATCH_COUPON
(
   match_id int not null,
   coupon_id int not null,
   UNIQUE (match_id, coupon_id),
   foreign key (match_id) references TST_MATCH(mt_id),
   foreign key (coupon_id) references TST_COUPON(cn_id)
);

@Entity
@Table(name = "TST_MATCH")
public class Match
{
   @Id
   @Column(name = "mt_id")
   private Integer id;
   
   @ManyToMany(mappedBy = "matchs", cascade = CascadeType.ALL)
   private List<Coupon> coupons;
   
   // ...
}
@Entity
@Table(name = "TST_COUPON")
public class Coupon
{
   @Id
   @Column(name = "cn_id")
   private Integer id;
   @ManyToMany(cascade = CascadeType.ALL)
   @JoinTable(
      name = "TST_MATCH_COUPON",
      inverseJoinColumns = { @JoinColumn(name = "match_id", referencedColumnName = "mt_id") },
      joinColumns = { @JoinColumn(name = "coupon_id", referencedColumnName = "cn_id") }
   )
   @MapKey(name = "id")
   private Map<Integer, Match> matchs;
   
   // ...
}