Question

我正在使用MOXy来解组一些推文并将它们存储在数据库表中。目前我正专注于解析推文。

我用以下内容开始了上下文：

unmarshaller = JAXBContext.newInstance(Tweet.class, User.class).createUnmarshaller();
unmarshaller.setProperty("eclipselink.media-type", "application/json");
unmarshaller.setProperty("eclipselink.json.include-root", false);

编辑3：简化模型

这是我正在使用的简单Json / JPA映射：

@Entity
@XmlRootElement
public class User implements Serializable {
    @Id public long id;
    public String name;
    public String screen_name;
}

和

@Entity
@XmlRootElement
public class Tweet implements Serializable {
    public @XmlJavaTypeAdapter(DateAdapter.class) Date created_at;
    public @Id long id;
    public String text;
    public @ManyToOne User user;
}

问题是，当我用以下内容解组推文时

Tweet tweet = unmarshaller.unmarshal(new StreamSource(new StringReader(msg)), Tweet.class).getValue();

tweet.getUser()始终返回null。

我无法理解为什么会这样，如果我遗失了什么;我无法找到启发性的答案。

编辑2 :(将EDIT 1替换为工作示例和输出）：

根据评论请求，我提供了一个示例推文：

{
    "created_at":"Wed Nov 02 14:18:24 +0000 2016",
    "id":793819553092558848,
    "id_str":"793819553092558848",
    "text":"Day of the Dead Google doodle marks Mexico’s holiday honoring life &amp; death *url removed*,
    "source":"<a href=\"http://www.hootsuite.com\" rel=\"nofollow\">Hootsuite</a>",
    "truncated":false,
    "in_reply_to_status_id":null,
    "in_reply_to_status_id_str":null,
    "in_reply_to_user_id":null,
    "in_reply_to_user_id_str":null,
    "in_reply_to_screen_name":null,
    "user":{
        "id":1266274663,
        "id_str":"1266274663",
        "name":"Nitin Solanki",
        "screen_name":"SolankiNit",
        "location":"India,Mumbai",
        "url":"*url removed*",
        "description":"I am passionate & engaged in #SEO #PPC #SocialMedia activity Since 2008. Sharing Trending Content & Useful Resources on #DigitalMarketing & much more. Thanks!!",
        "protected":false,
        "verified":false,
        "followers_count":689,
        "friends_count":632,
        "listed_count":64,
        "favourites_count":304,
        "statuses_count":11297,
        "created_at":"Thu Mar 14 05:30:59 +0000 2013",
        "utc_offset":19800,
        "time_zone":"Chennai",
        "geo_enabled":true,
        "lang":"en",
        "contributors_enabled":false,
        "is_translator":false,
        "profile_background_color":"8B542B",
        "profile_background_image_url":"http://abs.twimg.com/images/themes/theme8/bg.gif",
        "profile_background_image_url_https":"https://abs.twimg.com/images/themes/theme8/bg.gif",
        "profile_background_tile":false,
        "profile_link_color":"9D582E",
        "profile_sidebar_border_color":"D9B17E",
        "profile_sidebar_fill_color":"EADEAA",
        "profile_text_color":"333333",
        "profile_use_background_image":true,
        "profile_image_url":"http://pbs.twimg.com/profile_images/479285935293468672/6bqotzuS_normal.jpeg",
        "profile_image_url_https":"https://pbs.twimg.com/profile_images/479285935293468672/6bqotzuS_normal.jpeg",
        "profile_banner_url":"https://pbs.twimg.com/profile_banners/1266274663/1415196380",
        "default_profile":false,
        "default_profile_image":false,
        "following":null,
        "follow_request_sent":null,
        "notifications":null
    },
    "geo":null,
    "coordinates":null,
    "place":null,
    "contributors":null,
    "is_quote_status":false,
    "retweet_count":0,
    "favorite_count":0,
    "entities":{
        "hashtags":[
        ],
        "urls":[
            {
                "url":"*url removed*",
                "expanded_url":"*url removed*",
                "display_url":"*url removed*",
                "indices":[
                    79,
                    102
                ]
            }
        ],
        "user_mentions":[
        ],
        "symbols":[
        ]
    },
    "favorited":false,
    "retweeted":false,
    "possibly_sensitive":false,
    "filter_level":"low",
    "lang":"en",
    "timestamp_ms":"1478096304568"
}

这是解析后的结果：

{id_str=793819553092558848, created_at=Wed Nov 02 14:18:24 CET 2016, truncated=false, id=793819553092558848, text=Day of the Dead Google doodle marks Mexico’s holiday honoring life &amp; death *url removed*, retweeted_status=null, user=null, retweeted=false}

为什么MOXy Json嵌套的Root元素被解组为null？

0 个答案: