java - 错误: Entities and Pojos must have a usable public constructor - Java

每当我尝试编译应用程序时，都会出现此错误

error: Entities and Pojos must have a usable public constructor. You can have an empty constructor or a constructor whose parameters match the fields (by name and type). - java.util.List

SystemMessagesEntity.java:

    @Entity(tableName = "system_messages")
    @TypeConverters(ReplyMessages.class)
    public class SystemMessageEntity {
        @PrimaryKey
        @NonNull
        public String messageId;
        public String title;
        public String body;
        public String color;
        public Integer date;
        public String icon;
        public String ad;
        public Integer isRead;
        public String ip;
        String id; //user_id
        @Embedded(prefix = "reply_")
        private List<ReplyMessage> reply_message;

        @Ignore
        public SystemMessageEntity() {
        }

        public SystemMessageEntity(String id, @NonNull String messageId, String title, String body, String color, Integer date, String icon, String ad, Integer isRead, String ip, List<ReplyMessage> reply_message) {
            this.id = id;
            this.messageId = messageId;
            this.title = title;
            this.body = body;
            this.color = color;
            this.date = date;
            this.icon = icon;
            this.ad = ad;
            this.isRead = isRead;
            this.ip = ip;
            this.reply_message = reply_message;
        }
    //getters and setters
}

ReplyMessages.java:

@TypeConverters(ReplyMessages.class)

公共(public)类ReplyMessage {

private String body = "";
private String userId = "";
private Integer date = 0;
private String id = "";
private String messageId = "";


@Ignore
public ReplyMessage() {
}

public ReplyMessage(String body, String userId, Integer date, String id, String messageId) {
    this.body = body;
    this.date = date;
    this.id = id;
    this.messageId = messageId;
    this.userId = userId;
}

这是TypeConverter:

public class ReplyMessages {

    @TypeConverter
    public static String ListToJson(List<ReplyMessage> replyMessages) {
        if(replyMessages == null) return null;
        Type type = new TypeToken<List<ReplyMessage>>() {}.getType();
        String json = new Gson().toJson(replyMessages, type);
        Log.i("JSON", "toJson: " + json);
        return replyMessages.isEmpty() ? null : json;
    }

    @TypeConverter
    public static List<ReplyMessage> JsonToList(String json) {
        Gson gson = new Gson();
        Type type = new TypeToken<List<ReplyMessage>>() {}.getType();
        List<ReplyMessage> replyMessages = gson.fromJson(json, type);
        return replyMessages;
    }
}

我想使用Retrofit从API获取JSON数据并将其存储在数据库中。JSON数据在对象的父数组(MessageReply)内具有一个对象数组(SystemMessagesEntity)。
我已经尝试了一切，并在StackOverflow中搜索了几乎所有问题，但没有发现任何问题。
编辑:当我单独使用SystemMessageEntity实体时，数据库运行良好。但是，当我添加ReplyMessage实体时，出现了问题。
编辑2:通过删除ReplyMessage的List<>已解决了该问题。我不知道为何使用转换器但列表不起作用。

最佳答案

我已经解决了问题。好吧，似乎我不能将@Embedded与@TypeConverter一起使用主要是因为转换器返回一个String，并且它是原始类型，而不是POJO类。无论如何，我删除了@Embedded注解，它工作正常。