我正在制作一个应用程序，其中我使用room作为数据库缓存，并使用Retret2从服务器获取数据并将其保存在room数据库中，但从服务器获取数据后无法插入room数据库。

这是我下面的pojo类：

@Entity(tableName = "Users")
public class User {

@NonNull
@PrimaryKey
@SerializedName("_id")
private String _id;

@ColumnInfo(name = "name")
@SerializedName("name")
@Expose
private String name;

@ColumnInfo(name = "age")
@SerializedName("age")
@Expose
private String age;

public User(){}

public User(@NonNull String _id,String name, String age) {
    this._id = _id;
    this.name = name;
    this.age = age;
}

@NonNull
public String get_id() {
    return _id;
}

public void set_id(@NonNull String _id) {
    this._id = _id;
}

public String getName() {
    return name;
}

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

public String getAge() {
    return age;
}

public void setAge(String age) {
    this.age = age;
}
}

JSON反应

[
{
    "id": "5cf68fe7b439470017236249",
    "name": "Rhea",
    "age": "2"
},
{
    "id": "5d09006696a8470cbc7c34a2",
    "name": "Don",
    "age": "10"
},
{
    "id": "5d092d9858af5d22a80858bf",
    "name": "Roman",
    "age": "30"
},
{
    "id": "5d09e9976f3bad18b8fa54a0",
    "name": "Roman",
    "age": "30"
},
{
    "id": "5d09ea2ac127bd07b4b64f6f",
    "name": "Roman",
    "age": "30"
}
]

有人请告诉我发生了什么事。任何帮助都将不胜感激。