如何在领域android数据库中存储java列表 [英] how to store java list in realm android database

问题描述

我们如何将Java列表存储在领域android数据库中.我尝试使用模型中存在的setter方法存储它，但是它不起作用，并且在异常消息中得到'值'的每个元素必须是有效的托管对象".

How we can store java list in realm android database. I try to store it by using setter method present in my model, but it doesn't work and I get "Each element of 'value' must be a valid managed object" in exception message.

public void storeNewsList(String categoryId, List<News> newsList) { 
    Realm realm = Realm.getDefaultInstance(); 
    realm.beginTransaction(); 
    NewsList newsListObj = realm.createObject(NewsList.class); 
    newsListObj.setNewsList(new RealmList<>(newsList.toArray(new News[newsList.size()]))); 
    newsListObj.setCategoryId(categoryId); 
    realm.commitTransaction(); 
    realm.close(); 
} 

推荐答案

替换为

public void storeNewsList(String categoryId, List<News> newsList) { 
    try(Realm realm = Realm.getDefaultInstance()) { 
        realm.executeTransaction(new Realm.Transaction() {
             @Override
             public void execute(Realm realm) {
                 NewsList newsListObj = new NewsList(); // <-- create unmanaged
                 RealmList<News> _newsList = new RealmList<>();
                 _newsList.addAll(newsList);
                 newsListObj.setNewsList(_newsList); 
                 newsListObj.setCategoryId(categoryId);
                 realm.insert(newsListObj); // <-- insert unmanaged to Realm
             }
        }); 
    }
} 

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