kotlin data class 看下反编译的代码

kotlin

data class IdModel(val id: String)

对应的class文件反编译查看为

import kotlin.Metadata;
import kotlin.jvm.internal.Intrinsics;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;

@Metadata(mv = {1, 7, 1}, k = 1, xi = 48, d1 = {"\000\"\n\002\030\002\n\002\020\000\n\000\n\002\020\016\n\002\b\006\n\002\020\013\n\002\b\002\n\002\020\b\n\002\b\002\b\b\030\0002\0020\001B\r\022\006\020\002\032\0020\003\006\002\020\004J\t\020\007\032\0020\003H\003J\023\020\b\032\0020\0002\b\b\002\020\002\032\0020\003H\001J\023\020\t\032\0020\n2\b\020\013\032\004\030\0010\001H\003J\t\020\f\032\0020\rH\001J\t\020\016\032\0020\003H\001R\021\020\002\032\0020\003\006\b\n\000\032\004\b\005\020\006\006\017"}, d2 = {"Lbasic/IdModel;", "", "id", "", "(Ljava/lang/String;)V", "getId", "()Ljava/lang/String;", "component1", "copy", "equals", "", "other", "hashCode", "", "toString", "exposed_tutorial"})
public final class IdModel {
  @NotNull
  private final String id;

  public IdModel(@NotNull String id) {
    this.id = id;
  }

  @NotNull
  public final String getId() {
    return this.id;
  }

  @NotNull
  public final String component1() {
    return this.id;
  }

  @NotNull
  public final IdModel copy(@NotNull String id) {
    Intrinsics.checkNotNullParameter(id, "id");
    return new IdModel(id);
  }

  @NotNull
  public String toString() {
    return "IdModel(id=" + this.id + ')';
  }

  public int hashCode() {
    return this.id.hashCode();
  }

  public boolean equals(@Nullable Object other) {
    if (this == other)
      return true; 
    if (!(other instanceof IdModel))
      return false; 
    IdModel idModel = (IdModel)other;
    return !!Intrinsics.areEqual(this.id, idModel.id);
  }
}

在类的基础上自动添加了很多方法，同时也把class标记为了final，不可继承，这就有个问题， 我们又希望使用data class的便利，还想继承怎么搞，比如在mongodb里面我可能需要基础的class，记录了id和created，updated时间，如果每个类都搞一下，岂不是很烦人。