房间持久性：实体和Pojos必须具有可用的公共构造函数

Question

我正在尝试通过Room Persistence库将数据库添加到我的android应用中，并且出现此错误：

错误：实体和Pojos必须具有可用的公共构造函数。您可以有一个空的构造函数或一个其参数与字段匹配的构造函数（按名称和类型）。尝试了以下构造函数，但未能匹配：User（int，java.lang.String，java.lang.String，int，int，int，java.lang.String）-> [param：id->匹配字段：unmatched ，param：name->匹配字段：unmatched，param：gender->匹配字段：unmatched，param：age->匹配字段：unmatched，param：weight->匹配字段：unmatched，param：height->匹配字段：unmatched ，参数：锻炼->匹配字段：不匹配]

这是我的代码：

    @Entity
    public class User {

@PrimaryKey
private int userId;
private String userName;
private String userGender;
private int userAge;
private int userWeight;
private int userHeight;
private String workoutPlan;


public User(int id, String name, String gender, int age, int weight, int height, String workout) {

    this.userId = id;
    this.userName = name;
    this.userGender = gender;
    this.userAge = age;
    this.userWeight = weight;
    this.userHeight = height;
    this.workoutPlan = workout;

} ...

有人可以告诉我我做错了什么或错过了什么吗？

Answer 1

请更改参数名称，使其与实体属性匹配。

  public User(int userId, String userName, String userGender, int userAge, int userWeight, int userHeight, String workoutPlan) {
    this.userId = userId;
    this.userName = userName;
    this.userGender = userGender;
    this.userAge = userAge;
    this.userWeight = userWeight;
    this.userHeight = userHeight;
    this.workoutPlan = workoutPlan;
  } ...

为了保持持久性，它在Room中使用JavaBeans约定。有关更多信息：https : //developer.android.com/training/data-storage/room/defining-data#java